DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY

Composition of Co-Rich Ferromanganese Crusts and Substrate Rocks from the NW Marshall Islands and International Waters

to the North, Tunes 6 Cruise

by

James R. Hein 1 , Susan E. Zielinski 1 , Hubert Staudigel2, Se-Won Chang3 Michelle Greene 1 , and Malcolm S. Pringle4

Open File Report 97-482

1997

*U.S. Geological Survey, Menlo Park, CA2University of California, Scripps Institute (3Korea Institute of Geology, Mining, and M4Scottish Universities Research and Reactor Centre, Kilbride, UK

2University of California, Scripps Institute of Oceanography, La Jolla, CA 3Korea Institute of Geology, Mining, and Materials, Taejon, Korea

This report is preliminary and has not been reviewed for conformity with the U.S.Geological Survey editorial standards or with the North American Stratigraphic Code. Any

use of trade, product, or firm names is for descriptive purposes only and does not implyendorsement by the U.S. Government.

INTRODUCTION

Thirteen northwest Pacific seamounts and guyots were dredged during the Tunes 6 cruise, which took place from 31 October to 2 December, 1991 aboard the R.V. Thomas Washington under the direction of H. Staudigel. The primary objectives of the cruise were to study seamount ages and basalt chemistry in order to better understand the long term history of the South Pacific thermal anomaly (SOPITA). Representative ferromanganese oxyhydroxide crusts (Fe-Mn crusts) from most dredges were collected for this study, which extends our previous work on Fe-Mn crusts collected from the Marshall Islands and Federated States of Micronesia to seamounts located farther north (Hein, Kang et al., 1990; Hein, Ann et al., 1992).

Most dredge recoveries were from 11 seamounts located in international waters north of the Marshall Islands Exclusive Economic Zone (EEZ), whereas only one seamount was sampled within the EEZ of the Marshall Islands (Fig. 1; Table 1). A total of 35 dredges were attempted and 23 recovered Fe-Mn crust samples and substrate rocks. One or two dredge hauls recovered samples from most guyots, however, Vlinder and Batiza Guyots yielded five and four dredge haul recoveries, respectively. Several guyots had previous bathymetric surveys (Batiza, Jennings, Maloney, Missy, Golden Dragon), or were crossed because they were close to the ship's track (Alcatraz, Bellevue) and therefore only minor additional bathymetric surveys were conducted during Tunes 6.

Most volcanic edifices studied are flat-topped guyots and many of those appear from seismic-reflection records to be devoid of summit reefs. However, Jennings Guyot yielded Cretaceous shallow-water limestone and five other guyots (mostly at the western end of the Marcus-Wake seamount group) yielded carbonates. Bellevue, Alcatraz, and Seth Guyots have steep and smooth upper flanks that are morphologically uniform to great depths, indicating carbonate thicknesses up to 1000 m. Drowned atolls typically have steep upper flanks that slope at 24-36° and the reefs form a 20-40 m rim around the summit platform. Vlinder Guyot has a volcanic cone projecting through the summit platform, indicating rejuvenation of volcanism. Guyots without limestones typically have summits that slope at low angles from a central high to the main break in slope between the summit and flanks. Below the main slope break, flanks slope at 12-20° down to the abyssal seafloor.

This report presents data for those dredge hauls from which Fe-Mn crusts were studied. Data include sample descriptions, detailed chemical (major, minor, Pt-group, and rare earth elements) and mineralogical analyses of bulk Fe-Mn crusts and individual crust layers, and major oxide compositions and mineralogy for substrate rocks collected during the Tunes 6 cruise. Correlation coefficients are used to determine relationships between elements and Q-mode factor analysis to determine the grouping of elements with various crust phases.

METHODS

X-ray diffraction was completed on a Philips diffractometer using Cuka radiation and a curved-crystal carbon monochromator. Abundances of major oxides in substrate rocks were determined by X-ray fluorescence spectroscopy (Taggart et al., 1987), Fe(II) by colorimetric titration (Peck, 1964), CO2 by coulometric titration (Engleman et al., 1985), H2O+ by water evolved at 925°C as determined coulometrically by Karl-Fischer titration (Jackson et al., 1987), and H2O- by sample weight difference at 110°C for greater than one hour (Shapiro, 1975). The low totals for the phosphorite samples occur because fluorine and sulfur were not determined and therefore are not included in the totals. High fluorine (to 4.4%) and sulfur (to 2.1% 803) contents are typical of marine carbonate fluorapatite (Cullen and Burnett, 1986; Burnett et al., 1987; Hein et al., 1993). For Fe-Mn crusts, the concentrations of most major and minor elements were determined by inductively coupled

plasma-atomic emission spectrometry, except those of K, Zn, and Pb, which were determined by flame atomic-absorption spectroscopy, and those of As, Cr, and Cd, determined by graphite-furnace atomic absorption spectroscopy on air-dried samples (Aruscavage et al., 1989). Concentrations of platinum-group elements (PGEs) and rare earth elements (REEs) for Fe-Mn crusts were determined by inductively coupled plasma- mass spectrometry (Lichte et al., 1987a,b).

The usual Pearson product moment correlation coefficient was used to calculate the correlation coefficient matrices. For Q-mode factor analysis, each variable percentage was scaled to the percent of the maximum value before the values were row-normalized and cosine theta coefficients calculated. Factors were derived from orthogonal rotations of principal component eigenvectors using the Varimax method (Klovan and Imbrie, 1971). All communalities are >0.93. Low factor scores, < 10.21, were discarded because they are not statistically significant.

SUBSTRATE ROCK DESCRIPTIONS AND COMPOSITION

Substrate rocks in decreasing order of abundance are basalt, breccia, phosphorite, hyaloclastite, limestone, volcaniclastic siltstone and sandstone, and mudstone (Table 1). As many as five different rock types were recovered in a single dredge haul. As seen in hand samples, breccias most commonly consist of basalt clasts in a hyaloclastite matrix, and/or carbonate fluorapatite (CFA) cement. Many samples have Mn oxide impregnations that commonly form dendrites. Volcanogenic clasts in breccias and volcaniclastic rocks are commonly replaced by clay minerals and iron oxides. Basalts are aphanitic with common plagioclase phenocrysts and CFA infilling fractures and vesicles. Some samples have vesicles filled with carbonate mud or Fe-Mn oxides. Reef limestones consist of rounded carbonate clasts with calcite cement and moldic porosity; pelagic limestones are micritic and bioturbated to massive. Mudstones are mostly bioturbated with Fe-Mn oxides lining some burrows. Phosphorites have carbonate mud in cracks and Fe-Mn oxide impregnations.

X-ray Diffraction Mineralogy and Petrography

Primary Volcanogenic and sedimentary minerals include plagioclase, pyroxene, magnetite, and calcite; and secondary minerals include CFA, smectite, calcite, phillipsite, clinoptilolite, goethite, hematite, barite, and potassium feldspar (Table 2). Secondary CFA is the most abundant mineral in these samples and occurs in 73% of the samples as a major or moderate constituent, regardless of rock type (Table 2).

Hyaloclastite and hyaloclastite breccias consist chiefly of CFA and phillipsite (Table 2), with moderate to minor amounts of plagioclase, pyroxene, and magnetite. Most samples contain minor amounts of smectite. One sample consists predominantly of goethite. Hyaloclastites are predominantly completely altered to phillipsite, clinoptilolite, smectite, and Fe oxides, which in turn are cemented by CFA and/or replaced in varying degrees by CFA. Consequently, all gradations exist from altered hyaloclastite to phosphorite with relict hyaloclastite textures. Vesicles are lined with smectite and infilled by zeolites.

Mineralogically, most basalts consist chiefly of plagioclase and pyroxene, although some contain large amounts of CFA, hematite, and goethite. One sample (D21-2) is almost completely replaced by goethite and hematite, whereas another sample (D38-2) is nearly completely replaced by CFA, but shows a relict basalt microcrystalline texture. A wide range of basalt types were collected with variable amounts and combinations of plagioclase, pyroxene, olivine, and rarely amphibole phenocrysts. Groundmass textures include holocrystalline, subophitic, intersertal, microcrystalline, aphanitic, and doleritic. Samples range from highly vesicular to massive. Detailed descriptions of the basalts are available from H. Staudigel, Scripps Institution of Oceanography (see also Koppers, 1997).

Rocks identified as limestones from hand samples are overwhelmingly CFA mineralogically, with moderate amounts of plagioclase, calcite, barite, phillipsite, and potassium feldspar and trace amounts of chlorite, smectite, and quartz. Calcite is primary and the other minerals are due to various admixtures of volcanogenic grains and their alteration products, or to cementation and replacement. Barite forms veins and lenses. All gradations exist from unaltered limestone to phosphorite with relict limestone textures, especially CFA-replaced foraminiferal sands, some with abundant relict radiolarians.

Three types of mudstones were sampled from this region. The first type is composed mainly of magnetite, hematite, and smectite with lesser amounts of phillipsite and clinoptilolite. The second type of mudstone consists of variable amounts of CFA, potassium feldspar, smectite, phillipsite, and plagioclase, whereas the third type is composed solely of smectite. The first type is most likely either an altered ash or altered fine-grained hyaloclastite. The second type is a CFA-replaced altered volcaniclastic mudstone and the third type is bentonite.

Phosphorites are composed of CFA with plagioclase, smectite, and other minerals (Table 2). CFA commonly cements all of the clastic rock types and variably replaces grains in all rock types from incipient to complete replacement. The most commonly replaced rock type is pelagic limestone, where the foraminifera, radiolarians, other grains, and presumably the nannofossil matrix have been completely replaced by CFA. The grains (except the nannofossils) occur as ghosts. Barite veins and lenses commonly occur in the phosphatized pelagic limestone. In addition, shallow-water limestone, volcaniclastic rocks, hyaloclastite, and rarely basalt are completely replaced by CFA, thereby forming phosphorite.

Chemistry

The most P2Os rich CFA-replaced sedimentary rocks have CaO/?2Os ratios of 1.60 to 1.66 (Table 3), whereas theoretical chemical compositions for CFA range from 1.5 to 1.6 (Manheim and Gulbrandsen, 1979). The slight excess Ca over P in some of our samples is due to additional Ca associated with minor contamination by volcanogenic plagioclase, phillipsite cement (an alteration product of volcanic debris), and to relict calcite in the phosphatized limestone.

Smectite occurs in major to moderate amounts in 29% of the samples analyzed, and is especially abundant in the mudstones. It is found in at least trace amounts in over 70% of the samples analyzed. The one sample of nearly pure smectite (D33-3) has relatively high Al, Fe, and Mg contents and low Ca content, indicative of an iron-rich montmorillonite.

Phillipsite is also a common mineral, occurring in major to moderate abundances in 26% of the samples, primarily in the breccias and phosphatized limestones. The samples measured for chemistry, which have abundant phillipsite, have Si/Al ratios ranging from 3.0 to 3.4, which is higher than the range for most marine phillipsites (2.3-2.8) and significantly higher than the values for mafic igneous rocks (1.3-2.4; Kastner, 1979). These high values are the result of contamination by Si-rich volcanogenic and other phases.

Most of the basalt and basalt clasts in breccia are altered to smectite and goethite and are rarely replaced by phosphorite and phillipsite. Alteration is best characterized by increases in Fe2Os and water and decreases in FeO and K2O contents (Table 3). Volcaniclastic mudstones and hyaloclastites have compositions comparable to highly altered basalts.

FERROMANGANESE CRUSTS

Fe-Mn crusts studied here vary in thickness from 3 to 114 mm (Tables 1,4), although crusts were collected during Tunes 6 that range from a patina to 200 mm or more (D18,

South Wake Guyot). The thickest crust studied (114 mm) was dredged from the western flank of Vlinder Guyot in dredge D27. The thickest crust average from the various dredge hauls is 49 mm collected from Neen Koiaak Guyot in dredge D12. Limited availability of personnel on the Tunes 6 cruise did not allow for detailed records to be kept of maximum and average crust thicknesses for each dredge and the values listed in this report are predominately for samples analyzed here and from sketchy notes in the original logs.

Thicker crusts are composed of two or more layers, six being the maximum and two being the most common. Polished thin sections show that various layers are typically botryoidal, columnar, mottled, and laminated, in that order of abundance and are typical of other central Pacific crusts (Hein et al., 1992a). If the substrate rock has an irregular surface, then the first Fe-Mn oxyhydroxide layer is botryoidal, with initial points of growth being on the projections. If the substrate rock has a smooth surface, the first oxyhydroxide layer may be laminated, massive, or mottled. Mottled layers are porous and commonly have the most contamination by detrital minerals relative to the other layer types. Detrital minerals also accumulate between columns and are the chief cause for the directed growth of the columnar structure.

Growth Rates and Ages

Because the flux of Co into Fe-Mn crusts is relatively constant over time, growth rates can be determined from the Co content using the equation of Puteanus and Halbach (1988):

Growth Rate (mm/Ma) = 1.28 / (Co% - 0.24) (1)

The faster a crust grows, the lower the Co concentration. Crusts in which the older parts have been heavily phosphatized (>1 weight % P), however, do not have such a simple relationship because P dilutes the Co and likely mobilizes many of the metals within that older crust generation (Hein, Kang, et al., 1990; Koschinsky and Halbach, 1995). Growth rates in phosphatized parts of crusts may be determined using Co, Mn, and P contents and another set of equations of Puteanus and Halbach (1988):

CoW - Co(x)m (Mn / CoW) / (Mn / Co(b>) (2)

CoW" = CoW (1 - 0.05 AP)-1 (3)

where CoW is the Co concentration corrected for phosphate dilution; CoWm is the Co concentration measured in layer (x); Mn/CoW and Mn/Co(b) are the Mn/Co ratios measured in layer (x) and the boundary layer, respectively; AP is the difference between the CFA fraction of layer (x) and the average of the younger crust; and CoW" is the doubly corrected Co concentration in layer (x). Based on Co content for samples with less than one weight percent P and based on Co, P, and Mn contents for the remaining crust samples, growth rates for bulk crusts varied from 2.1 mm/Ma to 9.8 mm/Ma (Table 4). The average growth rate for bulk crusts was 5.0 mm/Ma, which is within the range of growth rates for hydrogenetic crusts (Hein et al., 1987b; 1990), but is a somewhat faster mean rate than for crusts from areas to the south and southeast. Growth rates for Tunes 6 crusts generally decrease with decreasing latitude, with the highest growth rates calculated for crusts from Oma Vlinder and Missy Guyots. Individual crust layers grew at rates from 2.2 to 14.3 mm/Ma.

The five thickest crusts analyzed, D27-5 (114 mm), D15-4 (95 mm), D 36-3 (81 mm), D25-3 (80 mm), and D41-1 (73 mm) began growing at 24.4, 37.5, 21.5, 15.8, and 13.0 Ma respectively, based on the growth rates of individual layers and the thickness of each

layer (Table 4). These ages of initiation of crust growth are minimum ages because the technique does not take into account dissolution and erosional unconformities which can add another several million years to the age of the crusts (Futa et al., 1988; Ingram et al., 1990; Ling et al., 1997). The oldest crust, from Aean Kan Guyot, is of late Eocene age (37.5 Ma), but is still 37-67 Ma younger than ages typical of central Pacific Cretaceous seamounts.

X-ray Diffraction Mineralogy

Great care was taken in sampling crusts for chemical and mineralogical analyses. All contamination from recent sediments was removed, which was especially critical in porous crust layers. Also, special attention was paid to obtaining a clean separation of the lower crust layers from the substrate. Any minerals or elements determined to exist in the various crust layers were incorporated into those layers during deposition or diagenesis and are not due to sampling procedures or post-depositional infiltration of sediment. Finally, all encrusting organisms and other debris were cleaned from the crust surfaces before sampling. Bulk always refers to the entire crust thickness, whether composed of layers or not.

All but two of the 79 samples of Fe-Mn crusts contain greater than 90% S-MnO? (vernadite; Table 5), which has only two X-ray reflections at about 2.42A and 1.41 A. X- ray amorphous Fe oxyhydroxide epitaxially intergrown with the §-MnO2 is also a dominant phase in these crusts, but is not included with the crystalline phases listed in Table 2. This X-ray amorphous iron phase crystallized to goethite in three of the bulk crusts and two of the individual layers analyzed. In the individual layers, goethite was present only in the innermost layer, indicating that those layers have undergone the most advanced diagenetic alteration. Two more samples, one an innermost layer (D41-1C) and the other a thin bulk crust (D14-17A), contain hematite, which is likely due to contamination by altered volcanogenic debris in the thin bulk crust, but may instead be due to diagenesis in the inner layer of the thick crust. CFA occurs in 24% of the bulk crusts and 19% of the layers analyzed. Layered samples contain up to 19% CFA, always within the innermost one or two layers of the crust. CFA is not found in the outer layers.

Quartz was found in all but three crusts. Of those samples that contain quartz, all but five have three percent or less quartz, whereas the other five have 4-5% quartz. Plagioclase (trace to 5%) was found in 75% of the samples. The quartz and some of the plagioclase are of eolian origin, carried by the westerlies from Asia, as there is no local or regional source for quartz in the west-central Pacific. The Marshall Islands are south of the main westerly wind belt which is reflected in lower quartz contents compared to crusts from higher latitudes (Hein et al., 1985a,b; 1987a; 1990). The remainder of the plagioclase, as well as the phillipsite, pyroxene, and calcite are reworked from local outcrops and incorporated into the crusts during precipitation of the Fe-Mn oxyhydroxides.

Calcite occurs in trace amounts in only two bulk samples of thin crusts and none of the layers. Calcite probably occurs from incorporation of biogenic calcite in the outermost millimeter of those crusts during accretion of the oxyhydroxides. The calcite is replaced by the oxyhydroxides once the incorporated calcite is buried by accretion of additional layers.

Todorokite is rare in hydrogenetic seamount crusts (Hein et al., 1987a), but occurs questionably in one of the samples analyzed here (D15-1B, Aean-Kan Guyot). Todorokite may form under different redox conditions than the more oxidized &-MnO2 phase, either during initial precipitation, during diagenesis, or during low-temperature hydrothermal precipitation. A diagenetic origin for D15-1 todorokite is unlikely because the crust is too thin for significant diagenesis.

Chemistry

Bulk Crusts: Chemical analyses for 84 samples and subsamples of crusts are presented in Tables 6 and 7 (normalized to 0% t^O"). General statistics for each dataset are presented in Tables 8, 9, and 10.

Water-normalized contents are often used because hygroscopic water varies with humidity in the lab in which samples are analyzed. Therefore, t^O", and consequently the abundances of other elements, will vary accordingly and significantly as hygroscopic water contents can be as high as 30%. Compositions normalized to 0% H2O" (Table 7) can be more meaningfully compared and may also more closely represent the grade of the potential ore. Consequently, the following discussion is based on hygroscopic water-free data.

The mean Fe and Mn contents of the 46 bulk crust samples are 16.7% and 22.1 %, respectively (Table 9). The mean Fe/Mn ratio (0.76) is comparable to the mean ratio for the entire central Pacific region (0.77; Hein et al., 1992b), but is somewhat higher than the mean ratio for the Marshall Islands EEZ (0.65; Hein, Kang, et al., 1990). Mean Fe content is less and Mn somewhat less compared to bulk crust samples from the Marshall Islands EEZ, 15.3% and 23.6%, respectively. The mean contents of the economically important metals Co (0.52%), Ni (0.40%), and Pt (0.50 ppm) are somewhat less than the Marshall Islands EEZ mean contents of 0.66%, 0.50%, and 0.58 ppm, respectively. The mean Co content is less, Ni about the same, and Pt much higher than mean contents for the equatorial Pacific. Phosphorus, a potential byproduct for mining, has a low mean value of 0.72% compared to the central Pacific mean of more than 1% and the Marshall Islands EEZ mean of nearly 2%.

Analysis of a large number of thick crusts lowers the mean contents of most metals (except platinum), and that is probably why this study shows mean concentrations below the regional and Marshall Islands means. Studies that include only analyses of thin crusts yield mean concentrations higher than those of regional means (for example, Pichocki and Hoffert, 1987; see Hein et al., 1992b for discussion).

Layers: In general, Co contents decrease from the outer surface to the substrate through Fe-Mn crusts (Halbach et al., 1982; Hein et al., 1985b); but in Tunes 6 samples, only about half show that decrease (Tables 6,7), whereas in the other half Co increases with depth; in one sample, the Co content remains unchanged with depth in the crust. This geographic area is unique in having so many samples that show an increase in Co with depth in the crusts. Other elements also change with depth in the crusts. Although there are exceptions, the following changes typically occur with depth in the Tunes 6 crusts: Fe, Si, Al, Pb, Cr, and As decrease, while Mn, Ni, Cu, Zn, Ba, Ce, and Pt increase.

Those trends indicate that, in general, elements representative of the aluminosilicate detrital fraction decrease toward the substrate (with notable exceptions), in contrast to the trend found in other studies. This decreasing trend with depth in the crusts is also true for the Fe oxyhydroxide phase and associated elements, whereas the Mn oxyhydroxide phase and associated elements show the opposite trend. Most of the PGEs increase toward the substrate, which is typical of the trend observed in other studies. Phosphorus remains relatively constant in thin crusts and increases significantly in the lower layers of thick crusts. Strongly phosphatized crusts disrupt the trends in the elements as noted above. A few crusts have the highest concentrations of elements in one of the internal layers.

Thinner crusts are similar chemically to the outer parts of thicker crusts. Thinner crusts (<15 mm) have less Mn and Co than thicker crusts and significantly less P, Cu, Mo, and Ni, but more Fe than thicker crusts. These trends are similar to those reported by Hein, Ann, et al. (1992) for Micronesian crusts, but contrast with trends in crusts from other areas. These differences probably are related to milder phosphatization of Tunes 6 crusts compared to those from other areas. Phosphatization dilutes these elements with depth in the crusts, making their overall grades lower than for thinner, non-phosphatized crusts. In addition to those element trends, thin crusts have higher Al, Si, K, and Cr and much lower

Pt concentrations than thick crusts. The Pt contents of two inner layers of thick crusts are extremely high, among the highest measured in any Pacific crusts, 2.1 ppm (D25-3D) and 2.7 ppm (D32-9H). The other PGEs are also very high in these crust layers.

Platinum Group Elements (PGEs)

We report the concentrations of Pt, Pd, Rh, Ru, and Ir for 19 bulk crusts and 33 crust layers (Tables 6,7). This is the fourth report of Ru and Ir contents in Fe-Mn crusts (see Hein, Kang, et al., 1990; Hein, Ann, et al., 1992; Hein, Gramm-Osipov, et al., 1994). Platinum contents vary from 0.133 ppm to 0.874 ppm for bulk crusts and from 0.133 ppm to 2.65 ppm for crust layers (Tables 9, 10). Palladium is below the limit of detection of 4 ppb (based on the original hygroscopic water-bearing dataset); the other PGEs vary by factors of three to nine: Rh (9.8-97.6 ppb), Ru (8.7-32.3 ppb), and Ir (4.1-22.3 ppb). The maximum values for each PGE (except Pd) are extremely high compared to those in other crusts analyzed to date. However, the mean values of bulk crusts are significantly less than mean values of Marshall Islands EEZ crusts for Ir, somewhat less for Pt and Rh, and somewhat more for Ru. The Tunes 6 PGE contents are significantly enriched over lithospheric and seawater abundances, but not over chondrite abundances (Figs. 2, 3; Parthe and Crocket, 1978; Hodge et al., 1986; Goldberg, 1987; Anders and Grevesse, 1989; Colodner, 1991; Bertine et al., 1993). For comparison, the sample with the highest PGE enrichment (D32-9H, layer 50-60 mm) is plotted in Fig. 3. Relative to chondrites, Ir and Ru ratios are a few times greater in D32-9H compared to the mean values for bulk crusts, Rh an order of magnitude greater, and Pt is enriched by three orders of magnitude. Relative to surface seawater, Ir is the most enriched for the mean bulk crust dataset, whereas Pt is the most enriched for sample D32-9H, but only somewhat more enriched than Ir, Ru, and Rh. Pd probably has about the same enrichment for both mean crust and most enriched crust datasets.

The highest Pt, Rh, and Ir concentrations occur in the inner layer of crust D32-9H, which was recovered from the deepest water dredge site, whereas the highest Ru content is in the innermost layer of crust D18-1C. Enrichment of PGEs in the inner parts of crusts is common for central Pacific crusts. The highest Pd and Ru concentrations occur in crusts from the Yap and Mariana arcs, as do other elements indicative of clastic input. As shown in previous studies, Pt, Ir, and Rh are derived predominantly from seawater, whereas Pd and much of the Ru are derived from clastic debris, the remainder of the Ru being derived from seawater. The extraterrestrial component (meteorite debris) in the bulk crusts is small. However, meteorite debris may be concentrated locally in the crusts by formation of dissolution unconformities, or by proximity of the crust to meteorite fallout during formation of the layer. Localized extraterrestrial debris-rich horizons, however, do not alter the overall hydrogenetic signature of the PGEs in the crusts. The high Pt contents in three crusts studied here occur over many millimeters of the inner crusts, which represent millions of years of accretion of Fe-Mn oxyhydroxides and therefore cannot be explained as the result of meteorite impacts, as those are essentially instantaneous events and would form only a very thin lamina in the crusts. In addition, the PGE ratios are non-chondritic, with Fe-Mn crust compositions showing more than an order of magnitude more Pt relative to Ir and Rh relative to Ir. More likely, Pt is a redox sensitive element and its changing concentration reflects changing redox conditions and diagenesis (see Hein et al., 1997).

Rare Earth Elements (REEs)

The concentrations of REEs are reported for 19 bulk crust samples and 33 individual crust layers (Table 11). For bulk crusts, ZREEs range from 0.13% to 0.32%, with a mean

of 0.21%. Nearly the same range is found for individual layers (0.14-0.35%) (Table 11). Out of 13 samples in which layers were analyzed, 11 of those show increases of EREEs with depth in the crusts; the other two samples show the opposite trend although the differences in percentages of EREEs between layers is quite small in those two samples. For crusts D18-1, D23-1, D37-4, and D41-1, the outer layer of each crust has the highest concentration of each REE, except Ce, which is highest in the middle layer. This is the same trend reported by Hein, Ann, et al. (1992) for crusts from Micronesia. D15-4 and D27-1 show the same trends, but also have inner layers with the highest Yb contents. For crusts D25-3, D27-5, D32-9, D36-3, and D42-1, the innermost layers have the highest concentrations of all REEs. D-32-8 has the highest concentrations of all the REEs except Ce in the middle layer.

Chondrite (Anders and Grevesse, 1989)-normalized patterns show a positive Ce anomaly (2Ce/La+Pr from chondrite-normalized data), light REE enrichment, and a slight decrease in heavy REEs with increasing atomic number; whereas, post-Archean Australian shale (PAAS; McLennan, 1989)-normalized patterns show nearly flat heavy REEs, light REE depletion, and positive Ce anomaly (Fig. 4). Normalized REE patterns for bulk crusts and layers are shown in Figures 4-17. Patterns for individual samples (Figs. 5-17), in additional to the above characteristics, show a small positive Gd anomaly, typical of hydrogenetic Fe-Mn crusts and of seawater (Hein et al., 1988). In crusts where two layers were analyzed, the largest Ce anomaly occurs in the inner layer as does the highest enrichment of Ce relative to chondrites. When more than two layers were analyzed, the largest Ce anomaly was either in an interior layer or the innermost layer, whereas the greatest enrichment relative to chondrites occurred in the innermost layer.

Interelement Relationships

Correlation coefficient matrices were constructed from the chemical compositions of 46 bulk crusts (Table 12), nine thick bulk crusts (>70 mm; Table 13), five thin bulk crusts (<11 mm; Table 14), five layers from D27-5 (Table 15), and five layers from D32-9 (Table 16). In addition to 28 elements, all matrices include H2O+, H2O, CO2, LOI, and the tables for bulk crusts include longitude, latitude, water depth, and crust thickness.

For the 46 bulk crusts, statistically significant positive correlations at the 99% confidence level are found among the following selected elements, listed in order of decreasing significance for each element (Table 12): Mn: Mo, H2O+, LOI, Ni, Zn, H2O~, Cu, Co, Cd, V, Ti; Fe: Na, As, Si, V; Si: Al, Na, K, Mg, Cr, As; P: CO2, Ca, Y, Sr, Mo; Ba: Ce, Sr, V, Mo, Pb, Y, Zn, Ti, Ca; Pt: Rh, Ir.

All elements are associated with one or more mineral phase(s) in the crusts. We interpret these correlations and others in Table 12 to indicate the following phases and their associated elements: 8-MnO2: Mn, Ni, Co, Mo, Cd, Cu, V, Ti; Fe oxyhydroxide: Fe, V, As; aluminosilicate: Si, Al, K, Na, Mg, Cr, As; CFA: Ca, P, Y, CO2, Sr; residual biogenic: Ba, Zn, V, Cu, Ce, Sr, Y, Ca. In general, these interelement associations are similar to those determined for crusts from other areas of the central Pacific, although regional differences do occur (Hein et al., 1990,1992b; Hein, Kang, et al., 1990).

Weak correlations exist for dredge haul locations and crust compositions. Y increases with increasing latitude (to the north) and Zn, Mn, Fe, Co, and V increase with increasing longitude (to the east), whereas Co and Zn decrease with increasing latitude. Only Ti increases with increasing water depth. Most PGEs (Pt, Ir, Rh), the CFA phase, and Ni increase with increasing crust thickness, whereas the iron and aluminosilicate phases decrease with increasing crust thickness.

For the nine bulk crusts thicker than 70 mm (Table 13), the following positive correlations between elements are found: Mn: Zn, Na, Pb, As, Co, H2O+; Fe: Ba, Mg,

Ti, Cu, H2O-, Si, Na, K, Al, LOI; Si: K, Fe, H2O~, Al, Ti, Ba, Cu, Mg, Ce, LOI; P: Ca, CO2, Sr, Y; Ba: Fe, Si, Na, Mg, Ti, H2Q-, Cu, Zn, Ru; Pt: Co, IT. Notable differences from the entire bulk crust dataset are the correlations of Pb with Mn and Cu with Fe. Fe and Ti are more strongly associated with the aluminosilicate phase and there has been a transfer of elements between the residual biogenic and iron oxyhydroxide phases. These differences indicate that diagenesis has affected the thicker crusts. The CFA phase and crust thickness decrease with increasing latitude. Co increases and Ce decreases with increasing longitude. With increasing water depth, Al, K, Ti, Si, Cu, Ce, and Cr increase and Ni, Co, Sr, and Cd decrease.

The five thin bulk crusts (<11 mm) have statistically significant positive correlations between the following elements (Table 14): Mn: H2O~, Ca, Ba, LOI, Co, and at just below the 95% confidence level, Ni and Mo; Fe: P, Sr, Pb, As; Si: none; P: Fe, Sr, V, As; Ba: Mo, Mn, LOI, Y. These thin crusts have no CFA mineralization and P is correlated with Fe, and Ca with the Mn phase. These correlations indicate that there are at least two mechanisms that incorporate P into crusts: Syndepositional adsorption and later- stage diagenesis. No elements are correlated with crust thickness, water depth, or latitude. With increasing longitude, Mo, Ba, LOI, Y, V, and CO2 increase, whereas Si, Al, and Cu decrease.

For the five layers of crust D27-5 (west side of Vlinder Guyot), the following elements have statistically significant positive correlations (Table 15): Mn: H2O', LOI, Ni, Cu, Rh, Ir; Fe: H2O+ , As; Si: H2O+; P: Ca, Y, CO2 , Sr, Ba; Ba: Ca, P, Sr, Ce; Pt: Rh, Ir, Zn, Cu. There is a strong negative correlation between layer thickness and Si and H2O+. The hydrogenetic PGEs may be associated with the Mn phase.

The five crust layers from D32-9 (Oma Vlinder Guyot) have the following positive element correlations (Table 16): Mn: Ti; Fe and Si have none; P: Ca, Ba, Y, Pt, Rh, Ir; Ba: Ir, Rh, Pt, Ca, P, Ce, Al; Pt: Rh, Ba, Ir, Ce, Ca, P, Al, Y. The interesting aspect of these correlations is the possible association of the PGEs with the CFA phase; or the CFA phase and some other PGE-bearing phase may simply co-vary. However, Ir and Rh have perfect correlations with Ba.

The only association common to all of these groups is the composition of CFA, with Ca, P, Y, CO2, and Sr being consistently positively correlated.

Grouping of Elements: Q-Mode Factor Analysis

Q-mode factor analysis was completed on chemical data for the 46 bulk crusts (Figs. 18,19). Grouped elements are assigned to five factors, four of which are essentially the same as those interpreted from the correlation coefficient data. Factor analysis did not identify a group of elements that we interpret as a residual biogenic phase from correlation coefficients. Instead, factor 2 is a PGE-bearing phase that may or may not be a residual biogenic phase. Two elements that have factor scores somewhat less than the 10.21 cutoff are Sr and Mg, which are commonly part of a residual biogenic (loosely bound) phase and support the interpretation of factor 2 as a residual biogenic phase. Differences are minor in elements assigned to the other four phases through interpretation of correlation coefficients and Q-mode factor assignments. Q-mode factor analysis does not include V, Ti, and Cu in the 6-MnO2 phase; V in the FeOOH phase; Cr and As in the aluminosilicate phase; and Sr in the CFA phase. Factor analysis additionally includes Ba in the FeOOH phase; Ti and Fe in the aluminosilicate phase; and Mo in the CFA phase.

The statistical data show that the partitioning of elements in crusts is complex and that many elements occur in several crust phases. Element distributions depend on the location of Fe-Mn crust formation that is both geographic and water depth locations. Distributions also depend on crust thickness, which reflects changes in growth rates with time and

10

diagenesis within the thicker crusts. Compositions further depend on global oceanic and atmospheric changes, which manifest in temporal changes in seawater chemistry.

RESOURCE CONSIDERATIONS

The commonly cited cut off grade for potential economic development is 0.8% Co and the cut off thickness is 40 mm. On a water-free basis, these samples are high in Pt (0.50 ppm); high in Mn (22.1%); and moderate in Ni (0.40%), Co (0.52%), and Cu (0.14 %), with a mean Co+Ni+Cu content of 1.06%. The mean crust thickness is 40 mm, but the true mean crust thickness from each dredge is poorly known.

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Hein, J.R., Manheim, F.T., Schwab, W.C., and Davis, A.S., 1985a, Ferromanganesecrusts from Necker Ridge, Horizon Guyot, and S.P. Lee Guyot: Geologicalconsiderations. Marine Geology, v. 69, p. 25-54.

Hein, J.R., Manheim, F.T., Schwab, W.C., Davis, A.S., Daniel, C.L., Bouse, R.M.,Morgenson, L.A., Sliney, R.E., Clague, D.A., Tate, G.B., and Cacchione, D.A.,1985b, Geological and geochemical data for seamounts and associated ferromanganese

11

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Hein, J.R., Schwab, W.C. and Davis, A.S., 1988, Cobalt and platinum-richferromanganese crusts and associated substrate rocks from the Marshall Islands. Marine Geology, v. 78, p. 255-283.

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Hein, J.R., Kirschenbaum, H., Schwab, W.C., Usui, A., Taggart, J.E., Stewart, K.C., Davis, A.S., Terashima, S., Quinterno, P.J., Olson, R.L., Pickthorn, L.G., Schulz, M.S., Morgan, C.L., 1990, Mineralogy and geochemistry of Co-rich ferromanganese crusts and substrate rocks from Karin Ridge and Johnston Island, Farnella Cruise F7- 86-HW. U.S. Geological Survey Open File Report 90-298, 80 pp.

Hein, J.R., Ahn, J.-H., Wong, J.C., Kang, J-K., Smith, V.K., Yoon, S-H., d'Angelo, W.M., Yoo, S-O., Gibbs, A.E., Kirn, H-J., Quinterno, P.J., Jung, M.-Y., Davis, A.S., Park, B.-K., Gillison, J.R., Marlow, M.S., Schulz, M.S., Siems, D.F., Taggart, J.E., Rait, N., Gray, L., Malcolm, M.J., Kavulak, M.G., Yeh, H.-W., Mann, D.M., Noble, M., Riddle, G.O., Roushey, B.H., and Smith, H., 1992, Geology, geophysics, geochemistry, and deep-sea mineral deposits, Federated States of Micronesia: KORDI-USGS R.V. Farnella cruise F11-90-CP. U.S. Geological Survey Open File Report 92-218, 191 pp.

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Hein, J. R., Schulz, M. S., Gein, L. M., 1992b, Central Pacific cobalt-richferromanganese crusts: Historical perspective and regional variability: in Keating, B. H., and Bolton, B. R., (eds.), Geology and Offshore Mineral Resources of the Central Pacific Basin. Circum-Pacific Council for Energy and Mineral Resources, Earth Sciences Series, v. 14, New York, Springer-Verlag, p. 261-283.

Hein, J.R., Yeh, H.-W., Gunn, S.H., Sliter, W.V., Benninger, L.M., and Wang, C- H., 1993, Two major Cenozoic episodes of phosphogenesis recorded in equatorial Pacific seamount deposits. Paleoceanography, v. 8, p. 293-311.

Hein, J.R., Gramm-Osipov, L., Gibbs, A.E., Kalyagin, A.N., d'Angelo, W.M., Nachaev, V.P., Briggs, P.H., Bychkov, A.S., Davis, A.S., Gusev, V.V., Chezar, H., Gorbarenko, S.A., Bullock, J.H., Kraynikov, G.A., Siems, D.F., Mikhailik, E.V., Smith, H., Eyberman, M.F., Schutt, M.J., Beloglazov, A.I., Mozherovsky, A.V., and Chichkin, R.V., 1994, Description and composition of Fe-Mn crusts, rocks, and sediments collected on Karin Ridge, R.V. Aleksandr Vinogradov cruise 91-AV-

12

19/2: in Hein, J.R., Bychkov, A.S., and Gibbs, A.E. (eds.), Data and results from R.V. Aleksandr Vinogradov cruises 91-AV-19/1, north Pacific hydrochemistry transect; 91-AV-19/2, north equatorial Pacific Karin Ridge Fe-Mn crust studies; and 91-AV-19/4, northwest Pacific and Bering Sea sediment geochemistry and paleoceanographic studies. U.S. Geological Survey Open-File Report 94-230, p. 39- 91.

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13

Puteanus, D. and Halbach, P., 1988, Correlation of Co concentration and growth rate: A method for age determination of ferromanganese crusts. Chemical Geology, v. 69, p. 73-85.

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14

Tab

le 1

. Lo

catio

n an

d de

scrip

tion

of d

redg

e ha

uls

from

Tun

es 6

cru

ise

Dre

dge

Num

ber

D9

DIG

D12

D13

D14

D15

D18

D19

D21

D22

D23

D25

D27

D28

D30

D31

Latit

ude

(N)

12° 0

6.00

' 12

° 03.

60'

12° 0

7.00

' 12

° 06.

50'

14°

19.7

0'

14° 2

0.60

'14

° 17

.06'

14

° 17

.40'

14° 4

7.04

' 14

° 47.

08'

14° 5

2.10

' 14

° 50.

00'

19° 3

0.70

' 19

° 30.

50'

19° 4

3.00

' 19

° 45.

75'

20°

10.5

0'

20°

09.9

8'20

° 14

.32'

20

° 13

.00'

21°

03.4

0'

21°

03.0

0'20

° 26.

94'

20° 2

7.06

'16

° 59.

24'

16° 5

9.55

'17

° 02.

25'

17° 0

2.26

'16

° 3 1

.70'

16

° 3 1.

50'

16° 3

0.40

' 16

° 30.

70'

Long

itude

(E

)

164°

56.

25'

164°

56.

25'

165°

00.

70'

165°

01.

20'

160°

52.

50'

160°

53.

20'

160°

54.

60'

1 60°

55.

80'

160°

18.

23'

160°

18.

68'

160°

20.

97'

160°

18.

68'

157°

44.

70'

157°

45.

00'

1 56°

45.

50'

156°

45.

75'

156°

40.

90'

156°

40.

64'

156°

23.

80'

156°

25.

00'

157°

09.

20'

157°

09.

60'

155°

55.

25'

155°

55.

17'

154°

10.

06'

154°

01.

62'

154°

02.

26'

154°

04.

29'

154°

2 1.

50'

154°

22.

00'

154°

2 1.

70'

154°

22.

50'

Wat

er D

epth

O

n-O

ff

Bot

tom

(m

)30

00-1

500

3000

-150

0

1500

3200

-200

0

2800

-303

5

2200

-143

0

2700

-220

0

2800

-225

0

2700

-220

0

2200

2400

-220

0

2300

-210

0

3100

-290

0

3200

-220

0

2800

-160

0

2400

-180

0

Guy

ot

Wod

ejeb

ato

Wod

ejeb

ato

Nee

n K

oiaa

k

Nee

n K

oiaa

k

Aea

n-K

an

Aea

n-K

an

Sout

h W

ake

Bat

iza

Bat

iza

Bat

iza

Mal

oney

Bat

iza

Vlin

der

Vlin

der

Om

a V

linde

r

Om

a V

linde

r

Max

Cru

st

Thic

knes

s (m

m)

110

65 120

14 50 102

68 26 20 31 110

85 122

13 22 45

Avg

. Cru

st

Thi

ckne

ss

(mm

)42 26 10

5 11 22 40 24 18 9 18 51 42 57 7 14 33

Gen

eral

Des

crip

tion

Bas

alt,

volc

anic

last

ic r

ocks

, se

dim

enta

ry a

nd h

yalo

clas

tite

brec

cia,

ph

osph

orite

, Fe

-Mn

crus

tB

asal

t, se

dim

enta

ry a

nd h

yalo

clas

tite

brec

cia,

ph

osph

orite

, Fe

-Mn

crus

tH

yalo

clas

tite,

pho

spho

rite,

Fe-

Mn

crus

t, ba

salt,

cla

stic

roc

ks

show

ing

brec

ciat

ion

and

cem

enta

tion

Bas

alt,

hyal

ocla

stite

, ve

ry t

hin

Fe-M

n cr

ust

Bas

alt,

phos

phat

ized

hy

aloc

last

ite b

recc

ia,

mud

ston

e, F

e-M

n cr

ust

Bas

alt,

phos

phor

ite,

brec

cia,

mud

ston

e, F

e-M

n cr

ust

Vol

cani

clas

tics,

bas

alt,

brec

cia,

pho

spho

rite

, Fe

-Mn

crus

t

Bas

alt,

hyal

ocla

stite

, ph

osph

orite

, Fe

-Mn

crus

t

Bas

alt,

hyal

ocla

stite

, Fe

-Mn

crus

t

Bas

alt,

volc

anic

last

ics,

bre

ccia

, cl

astic

lim

asto

ne

Bas

alt,

brec

cia,

hya

locl

astit

e, p

hosp

hori

te

Fe-M

n cr

ust,

basa

lt, p

hosp

hatiz

ed l

imes

tone

, pe

lagi

c ch

alk,

hy

aloc

last

ite,

phos

phor

iteFe

-Mn

crus

t, ba

salt,

vol

cani

clas

tics,

pho

spho

rite

, m

ud

Bas

alt,

Fe-M

n cr

ust,

mud

ston

e

Fe-M

n cr

ust,

phos

phor

ite b

recc

ia,

Cre

tace

ous

reef

lim

esto

ne,

pela

gic

chal

kC

reta

ceou

s re

ef l

imes

tone

, pa

legi

c ch

alk,

Mn-

crus

t, ph

osph

orite

br

ecci

a

Tab

le 1

Con

tinue

d

Dre

dge

Num

ber

D32

D33

D36

D37

D38

D41

D42

Lat

itude

(N

)

16°

23.8

0'

16°

25.3

0'20

° 53

.40'

20°

53.3

0'21

° 22

.10'

21°

22.4

5'21

° 15

.45'

21°

14.8

5'23

° 48

.10'

23

° 47

.80'

23°

49.2

0'

23°

49.1

0'23

° 53

.50'

23

° 54

.20'

Lon

gitu

de

(E)

154°

20.

80'

154°

21.

10'

154°

52.

00'

154°

53.

30'

153°

08.

80'

153°

09.

94'

153°

02.

45'

153°

04.

20'

150°

30.

00'

150°

32.

40'

148°

40.

50'

148°

40.

60'

148°

41.

50'

148°

42.

90'

Wat

er D

epth

O

n-O

ff

Bot

tom

(m

)33

50-3

440

2700

-210

0

1700

-120

0

2600

-225

0

3100

-230

0

3400

-320

0

2400

-360

0

Guy

ot

Om

a V

linde

r

Mis

sy

Gol

den

Dra

gon

Gol

den

Dra

gon

Bel

levu

e

Seth

Seth

Max

Cru

st

Thi

ckne

ss

(mm

)75 14 10

5

60 61 73 60

Avg

. Cru

st

Thi

ckne

ss

(mm

)31 8 77 40 32 60 36

Gen

eral

Des

crip

tion

Bas

alt,

hyal

ocla

stite

bre

ccia

, lim

esto

ne,

phos

phor

ite,

Fe-M

n cr

ust

Mud

ston

e, F

e-M

n cr

ust,

silts

tone

, ph

osph

orite

, ba

salt

Bas

alt,

Fe-M

n cr

ust,

pela

gic

carb

onat

e, b

recc

ia,

hyal

ocla

stite

, ph

osph

orite

Bas

alt,

hyal

ocla

stite

, M

n-cr

ust,

min

or c

arbo

nate

, ph

osph

orite

Hya

locl

astit

e, b

asal

t, Fe

-Mn

crus

t an

d no

dule

s, p

hosp

hori

te,

brec

cia

Vol

cani

clas

tics,

Fe-

Mn

crus

t, ba

salt

Bas

alt,

volc

anic

last

ics,

hya

locl

astit

e, p

hosp

hatiz

ed p

elag

ic

limes

tone

, ph

osph

orite

, pi

llow

bre

ccia

, Fe

-Mn

crus

t

Table 2. X-ray diffraction mineralogy of substrate rocks from Tunes 6 cruise

SampleD9-22BD9-24D10-1B

D10-3D10-5AD12-3BD13-13B

D14-17B

D14-18

D15-3D15-4ED18-3

D18-5BD21-2

D21-3BD22-1B

D23-1E

D23-5BD25-2B

D25-3ED25-3FD28-1B

D31-1BD32-6A

D32-8AD32-9AD32-9BD33-1B

D33-1CD33-1DD33-2BD33-3D37-1D38-2-1D42-1D

MajorlCFA2CFACFA

CFACFACFAPlagioclase pyroxeneK-feldspar magnetiteAmorphous smectite, CFAK-feldspar, CFACFAPhillipsite

CFAGoethite

SmectitePlagioclase smectitePhillipsite, CFA plagioclaseCFA, goethiteCFA

CFACFAK-feldspar

CFACFA

CFACFACFAClinoptilolite smectiteSmectiteSmectiteCFASmectiteCFACFAPhillipsite

ModerateCalcitePhillipsite, plagioclasePhillipsite

Plagioclase-PlagioclaseMagnetite

Hematite, smectite

-

SmectiteBariteMagnetite

-Calcite, hematite

-CFA, hematite

Plagioclase, pyroxenePlagioclase

Plagioclase-Pyroxene, CFA Phillipsite, plagioclase-Phillipsite, K-feldspar

Smectite-BariteMagnetite, hematite

Hematite, phillipsite-Phillipsite--Phillipsite, smectite-

Minor/TraceChloriteSmectiteSmectite

SmectiteSmectiteSmectite, quartzSmectite

-

-

_-Smectite plagioclase--

--

Smectite

SmectiteSmectite, quartz

Smectite-Smectite

Smectite, quartzSmectite clinoptilolite_K-feldspar-Plagioclase

Clinoptilolite_-__--

Rock/SedimentPhosphorite [clastic limestone)3CFA-cemented breccia4CFA-cemented breccia in contact w/ phosphorite (foraminifera sand)CFA-cemented brecciaPhosphorite (breccia)Phosphorite (sandstone)Basalt

Mudstone

Mudstone

MudstonePhosphorite (micritic limestone)Breccia

Phosphorite (foraminifera sand)Yellow-red mineral replacement of basaltYellow replacement mineralAmygdaloid basalt

CFA-cemented breccia

CFA-cemented brecciaPhosphorite (volcaniclastic calcareous sandstone)Phosphorite (hyaloclastite)PhosphoriteMudstone

Phosphorite (limestone)Phosphorite (limestone)

PhosphoriteWhite phosphoriteBrown fracture fillPale brown mudstone

Dark brown mudstoneGreen mudstonePhosphorite (limestone)MudstoneAuffPhosphoritePhosphorite (basalt)Botryoidal crystals in vug

1 Major: >25%, Moderate: >5% to <25%, Minor: <5% 2CFA is carbonate fluorapatite 3Rock types in parentheses are replaced by phosphorite 4A11 breccias are sedimentary, and most are volcaniclastic

17

Tab

le 3

. C

hem

ical

com

posi

tion

in w

eigh

t per

cent

of s

ubst

rate

rock

s fr

om T

unes

6 c

ruis

e

Si0

2A

12Q

3Fc

OFc

2O3

MR0

CaO

Na2

0K

20TK

)2P2

P5M

nOL

OI9

25C

°T

otal

H20

+H

20-

C02

CaO

/P2O

sR

ock

Typ

e

D9-

22B

10.1

3.02 nd 3.16

1.06

413

0.97

0.70

0.35

125

0.%

10.5

94.6

2

2.1 1.6

72 1.84

Phos

phor

ite

(cla

stic

Is)

D10

-1B

28.3

8.21

<0.0

16.

972.

5121

.21.

331.

511.

1212

.10.

3213

.096

.57

3.7

63 23 1.75

CFA

-cem

ente

d br

ecci

a

D12

-3B

7.89

2.42

0.04 1.70

0.37

44.2

0.99

0.67

0.35

27.5

0.07

6.45

92.6

5

2.2

0.48 4.3

1.61

Phos

phor

ite

(san

dsto

ne)

D13

-13B

47.0

15.1

32 9.34

4.49

8.99

3.45

1.44

2.68

0.76

0.24

2.56

99.2

5

1.4

1.4

0.07

11.8

Bas

alt

D14

-17B

43.5

15.5

nd 11.4

238

1.49

1.83

3.58

232

0.83 1.88

14.4

99.1

1

4.5

9.0

0.10 1.80

Mud

s ton

e

D15

-4E

3.84

0.83

<0.0

11.

150.

4142

.20.

830.

170.

1626

.30.

237.

0783

.19

2.1

0.50 4.4

1.60

Phos

phor

ite

(mic

ritic

Is)

D18

-5B

5.76

1.90

0.04 1.42

038

472

0.%

029

032

28.5

0.08

7.67

94.5

2

2.0

0.78 5.5

1.66

Phos

phor

ite

(Is

brec

cia)

D22

-1B

41.9

8.86 1.0

10.6

7.84 12.6

1.40

131

2.60

2.75

0.15

8.19

99.2

0

2.0

5.4

020

4.58

Am

ygda

loid

ba

salt

D25

-2B

6.90

1.74 nd 1.74

0.44

462

0.70

0.61

0.35

28.9

0.54

6.55

94.6

7

1.6

1.1 42 1.60

Phos

phor

ite

(vol

cani

clas

tic

calc

areo

us s

s)

Si02

Al^

FcO

Fc2<

*M

gOC

aON

a20

K20

TK>2

P2P5

MnO

LO

I 92

5C°

Tot

al

H^

H2Q

-

0^

CaO

/P2O

5R

ock

Typ

e

D25

-3E

20.1

5.85

<0.0

15.

11 1.36

30.0

1.42

1.31

1.09

18.7

0.17 11.5

96.6

1

3.0

5.6

2.9

1.60

Phos

phor

ite

(hya

locl

astit

e)

D28

-1B

44.0

13.4

nd 9.16

2.22

6.09

2.13

4.21

1.38

3.48

0.72

12.1

98.8

9

43 4.8

0.42

1.75

Mud

s ton

e

D31

-1B

3.60

1.02

<0.0

10.

840.

3949

.20.

770.

120.

0830

.30.

417.

5394

.26

1.9

0.80 5.3

1.62

Phos

phor

ite

(lim

esto

ne)

D32

-6A

12.7

03.

24<0

.01

3.05

0.78

37.3

1.34

0.78

0.39

23.4

0.16

12.9

96.0

4

0.20 5.8 1.8

1.59

Phos

phor

ite

(lim

esto

ne)

D33

-1B

44.3

12.7

<0.0

111

32.

670.

533.

102.

57 1.99

024

025

19.3

98.9

5

5.6

11.1

0.03

221

Mud

s ton

e

D33

-1C

36.7

13.6

0.20

13.9

2.53

0.44

1.78

1.55

2.66

0.24 0.1

26.2

99.9

0

2.5

13.5

0.02

1.83

Mud

ston

e

D33

-2B

14.0

3.64

<0.0

13.

510.

8937

.013

70.

870.

4523

202

410

.495

.57

0.40 52 33 1.59

Phos

phor

ite

(lim

esto

ne)

D33

-347

.412

.6<0

.01

9.15

4.15

0.43

222

135

1.73

0.16

0.12

20.6

99.9

1

4.3

133

0.02

2.69

Mud

s ton

e/tu

ff

Maj

or o

xide

s by

X-r

ay f

luor

esce

nce;

LO

I = L

oss

On

Igni

tion

at 9

25°C

; nd=

not

det

erm

ined

; an

alys

ts:

H.

Smith

, J. R

. G

illis

on, C

. J. S

keen

, U.S

. geo

logi

cal S

urve

y L

ow to

tals

are

due

to th

e pr

esen

ce o

f hig

h F,

Cl,

and

S, w

hich

is ty

pica

l of s

eam

ount

pho

spho

rites

Roc

k ty

pe in

par

enth

eses

was

repl

aced

by

carb

onat

e flu

orap

atite

; Is =

lim

esto

ne; s

s =

sand

ston

e

Table 4. Calculated growth rates of Fe-Mn crusts from Tunes 6 cruise

Sample

D9-11D9-22AD9-25AD9-25BD10-1AD12-3AD13-13AD14-11D14-17AD14-19AD15-1AD15-1BD15^AD15^BD15^CD15^DD18-1AD18-1BD18-1CD18-5AD19-1D19-2D21-3AD2MD22-1AD22-2D23-1AD23-1B,CD23-1DD23-5AD25-1D25-2AD25-3AD25-3BD25-3CD25-3DD27-1AD27-1BD27-1CD27^D27-5AD27-5BD27-5CD27-5DD27-5ED27-5FD28-1A

Type & Interval (mm) 1

Bulk (0-30)Bulk (0-41)Layer (0-23)Layer (23-43)Bulk (0-49)Bulk (0-45)Bulk (0-14)Bulk (0-30)Bulk (0-15)Bulk (0-29)Bulk (0-29)Bulk (0-20)Bulk (0-93)Layer (0-33)Layer (30-62)Layer (62-95)Bulk (0-68)Layer (0-18)Layer (18-56)Bulk (0-8)Bulk (0-26)Bulk (0-20)Bulk (0-15)Bulk (0-15)Bulk (0-30)Bulk (0-22)Bulk (0-70)Layer (0-25)Layer (25-70)Bulk (0-40)Bulk (0-55)Bulk (0-19)Bulk (0-83)Layer (0-24)Layer (24^6)Layer (46-80)Bulk (0-62)Layer (0-14)Layer (14-51)Bulk (0-18)Bulk (0-1 14)Layer (0-11)Layer (11-23)Layer (23-53)Layer (53-84)Layer (83- 114)Bulk (0-11)

Mn(wt.%)

26.021.324.119.627.124.323.122.819.624.020.615.320.925.027.616.129.024.130.921.519.924.218.120.020.118.723.021.327.625.123.018.224.522.628.823.422.622.720.819.721.918.219.725.421.416.418.2

P(wt.%)

0.330.450.350.350.320.390.390.320.310.352.195.522.870.360.366.090.400.400.320.440.370.350.360.360.400.470.390.360.401.850.360.350.410.370.370.591.460.392.600.381.370.430.370.411.474.280.32

Co (ppm)

84933856681841835683567661146166483058513732223349617371703426096777576482985645503361744774492749475355514242676069303848654681530647816319412135954412312151253962493551255501321721384799

Growth Rate (mm/Ma)2

2.18.82.97.23.93.93.53.45.33.7__3

2.52.62.82.32.93.82.23.94.93.45.45.15.04.34.76.93.5

5.25.64.45.43.37.46.16.46.04.74.75.14.74.15.17.45.3

Crust Age(Ma)14.34.77.910.712.611.54.18.82.97.8-

36.812.823.337.523.34.722.22.05.45.92.83.06.05.115.03.716.6-

10.63.418.84.511.215.810.22.28.43.8

24.52.26.914.120.224.42.1

19

Table 4 Continued

D30-1AD31-1AD32-2D32-5D32-6BD32-8BD32-8CD32-8DD32-8ED32-9CD32-9DD32-9ED32-9FD32-9GD32-9HD33-1AD33-2AD36-1D36-3AD36-3BD36-3CD36-3DD36-4D37-2D37-4AD37-4BD37-4CD38-1AD38-1BD38-1CD38-2-2AD41-1AD41-1BD41-1CD42-1AD42-1BD42-1C

Bulk (0-21)Bulk (0-45)Bulk (0-22)Bulk (0-72)Bulk (0-3)Bulk (0-40)Layer (0-5)Layer (5-20)Layer (20-40)Bulk (0-60)Layer (0-2)Layer (2-17)Layer (17-30)Layer (30-50)Layer (50-60)Bulk (0-10)Bulk (0-10)Bulk (0-72)Bulk (0-78)Layer (0-18)Layer (18-49)Layer (49-81)Bulk (0-76)Bulk (0-50)Bulk (0-50)Layer (0-30)Layer (30-50)Bulk (0-55)Layer (0-28)Layer (28-57)Bulk (0-13)Bulk (0-72)Layer (0-32)Layer (32-73)Bulk (0-20)Layer (0-7)Layer (7-20)

19.821.421.726.018.122.616.521.225.523.321.224.128.726.325.118.416.627.522.421.124.522.126.121.622.621.122.922.623.321.822.321.621.523.019.918.621.3

0.340.310.310.410.390.390.410.380.350.410.450.410.360.390.750.370.411.101.980.510.443.651.370.530.490.401.010.530.380.410.430.460.390.530.440.440.41

5013643465225328387654593295530567116036396852216019651040454331371357775013527757224297576154054515382649804927506239514849472345704775412238514933

4.93.23.14.48.74.214.34.43.03.58.24.53.53.17.86.69.8

3.84.53.93.4

4.36.19.05.05.14.88.35.25.55.95.47.48.85.1

4.314.27.116.50.49.60.43.810.517.00.33.67.213.715.01.51.0-

20.64.112.121.5-

11.78.33.37.410.95.88.32.513.15.413.02.70.83.4

Intervals measured from the outer surface of crusts2Growth rates determined via the equations of Puteanus and Halbach (1988); crust age was calculated from

growth rate and crust thickness; the age of a layer is for the base of that layer 3Growth rates and crust ages could not be determined because samples were heavily phosphatized and no

unphosphatized younger layers existed for comparison

20

Table 5. X-ray diffraction mineralogy of Fe-Mn crusts from Tunes 6 cruise

Sample

D9-11D9-22AD9-25AD9-25BD10-1AD13-13AD14-11D14-17AD14-19AD15-1AD15-1BD15-4AD15-4BD15-4CD15-4DD18-1AD18-1BD18-1CD18-5AD19-1D19-2D21-3AD21-4D22-1AD22-2

D23-1AD23-1B,CD23-1DD23-5AD25-1D25-2AD25-3AD25-3BD25-3CD25-3DD27-1AD27-1BD27-1CD27-4D27-5AD27-5BD27-5CD27-5DD27-5ED27-5FD28-1AD31-1AD32-2D32-5D32-6BD32-8BD32-8C

Type & Interval (mm)l

Bulk (0-30)Bulk (0-41)Layer (0-23)Layer (23-43)Bulk (0-49)Bulk (0-14)Bulk (0-30)Bulk (0-15)Bulk (0-29)Bulk (0-29)Layer (0-20)Bulk (0-93)Layer (0-33)Layer (30-62)Layer (62-95)Bulk (0-68)Layer (0-18)Layer (18-56)Bulk (0-8)Bulk (0-26)Bulk (0-20)Bulk (0-15)Bulk (0-15)Bulk (0-30)Bulk (0-22)

Bulk (0-70)Layer (0-25)Layer (25-70)Bulk (0-40)Bulk (0-55)Bulk (0-19)Bulk (0-83)Layer (0-24)Layer (24-46)Layer (46-80)Bulk (0-621Layer (0-14)Layer (14-51)Bulk (0-18)Bulk (0-114)Layer (0-11)Layer (11-23)Layer (23-53)Layer (53-83)Layer (83-114)Bulk (0-11)Bulk (0-45)Bulk (0-22)Bulk (0-72)Bulk (0-3)Bulk (0-40)Layer (0-5)

5-MnO2(%)2

9891100989397989397908193969990989610097949893979591

979798949890979898969499939895979999968193969897939792

Others (%)

1-goethite, <l-K-feldspar8-phillipsite, <l-amphibole, <l-goethitetrace -quartz1-goethite, <l-smectite, <l-quartz6-goethite, <l-smectite(?)2-quartz, 1-plagioclase1-plagioclase, 1 -quartz3-plagioclase, 2-quartz,. 2-hematite2-palygorskite, 1-plagioclase, <1 -quartz8-CFA, 1-plagioclase, 1 -quartz16-CFA, 1-plagioclase, 1 -quartz, 1-todorokite (?)6-CFA, <l-quartz, < 1-plagioclase3-quartz, 1-plagioclase< 1-plagioclase, <1 -quartz9-CFA, <l-geothite, <l-plagioclase, <l-quartz1-plagioclase, 1 -quartz2-CFA, 1-plagioclase, 1 -quartztrace-quartz2-quartz, 1-plagioclase5-quartz, 1-plagioclase1-quartz, <l-plagioclase, <l-smectite3-quartz, 2-plagioclase, 2-smectite (?)2-quartz, 1-plagioclase3-quartz, 2-plagioclase5-plagioclase, 2-birnessite, 1-quartz, <l-calcite, <1- smectite2-plagioclase, 1-quartz1-phillipsite, 1-plagioclase, 1-quartz1-plagioclase, 1-quartz5-CFA, < 1-plagioclase, 1-quartz1-plagioclase, <l-quartz, <l-smectite5-phillipsite, 3-plagioclase, 2-quartz1-CFA, 1-plagioclase, 1-quartz1-quartz, < 1-plagioclase1-plagioclase, 1-quartz2-phillipsite, 1-plagioclase, 1-quartz6-CFA, <l-quartz1-quartz6-CFA, 1-quartz1-plagioclase, < 1-quartz4-CFA, <l-quartz2-quartz, 1-plagioclase< 1-quartz1-quartz3-CFA, 1-quartz19-CFA5-phillipsite, 1-plagioclase 1-quartz2-quartz, 1-plagioclase, 1 -smectite1-chlorite (?), 1-quartz2-quartz, 1-plagioclase4-quartz, 2-plagioclase, 1 -smectite2-quartz, 1-plagioclase5-quartz, 3-plagioclase

21

TableS Continued

D32-8DD32-8ED32-9CD32-9DD32-9ED32-9FD32-9GD32-9HD33-1AD33-2AD36-1D36-3AD36-3BD36-3CD36-3DD36-4D37-2D37-4AD37-4CD38-1AD38-1BD38-1CD38-2-2AD41-1AD41-1BD41-1CD42-1AD42-1BD42-1C

Layer (5-20)Layer (20-40)Bulk (0-60)Layer (0-2)Layer (2-17)Layer (17-30)Layer (30-501Layer (50-60)Bulk (0-10)Bulk (0-10)Bulk (0-72)Bulk (0-78)Layer (0-18)Layer (18-49)Layer (49-81)Bulk (0-76)Bulk (0-50)Bulk (0-50)Layer (30-50)Bulk (0-55)Layer (0-28)Layer (28-57)Bulk (0-13)Bulk (0-72)Layer (0-32)Layer (32-73)Bulk (0-20)Layer (0-7)Layer (7-20)

9699999799999998939297959599839694979399979495979997989297

2-quartz, 1-plagioclase, 1-stevensite (?)1 -quartz< 1-plagioclase, <1 -quartz2-quartz, 1-plagioclase1 -quartz<l-clinoptilolite, < 1-stevensite1 -quartz1-CFA, 1 -quartz4-quartz, 2-plagioclase, <l-calcite (?), <1 -smectite5-quartz, 2-plagioclase2-CFA, < 1-plagioclase, <1 -quartz4-CFA, 1 -quartz3-quartz, 2-plagioclase1 -quartz16-CFA, 1-quartz2-CFA, 1-quartz, 1-plagioclase5-phillipsite, < 1-plagioclase, <l-quartz2-quartz, 1-plagioclase4-phillipsite, 2-CFA, < 1-plagioclase, < 1-quartz1-quartz2-quartz, <l-plagioclase, <1 -smectite2-plagioclase, 2-quartz, 1-CFA, 1 -smectite2-plagioclase, 1-CFA, 1-quartz2-plagioclase, 1-quartz1-quartz, < 1-plagioclase1 -hematite, 1-plagioclase, 1-quartz2-quartz4-plagioclase, 2-pyroxene (?), 2-quartz1-phillipsite, 1-quartz

llntervals measured from the outer surface of crusts^Percentages were determined by using the following weighting factors relative to quartz set at 1: 6-MnO2

70; todorokite 10; birnessite 12 (Hein et al., 1988); carbonate fluorapatite (CFA) 3.1; plagioclase 2.8;calcite 1.65; smectite 3.0; goethite 7.0; phillipsite 17.0; illite 6.0; pyroxene 5.0; halite 2.0 (Cook et al.,1975); the limit of detection for each mineral falls between 0.2 and 1.0%, except the manganese mineralswhich are greater, perhaps as much as 10% for 8-MnO2

22

Tab

le 6

. C

hem

ical

com

posi

tion

of F

e-M

n cr

usts

fro

m T

unes

6 c

ruis

e

|[ D

9-11

Fe

Wt%

Mn

Fe/M

nS

iN

aA

lK M

gC

aT

iP H

20+

H2O

CO

2L

OI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

12 19.0

0.63 2.4

1.2

0.41

0.40

0.68 1.9

0.88

0.24 5.8

27.0

0.34

39.9

4000

690

490

6200

1100

370

1200

650

140

490

1100

10.0

3.3

170 - - - - -

BO

-30

Cru

st

D9-

22A

13 16.0

0.81 3.5 1.4

0.96

0.49

0.67 2.0

0.81

0.34 7.1

24.8

0.35

37.7

3200

2100

570

2900

1700

270

1200

740

130

490

920

9.6

2.5

170 - - - - -

BO

-41

Cru

st

D9-

25A

1

13 18.0

0.72 3.0 1.3

0.53

0.41

0.66 1.9

0.88

0.26 8.7

25.2

0.41

38.5

3100

980

460

5100

1100

350

1200

700

160

510

1100

9.1

2.3

190 - - - - -

LO

-23

Cru

st

D9-

25B

15 15.0

1.00 3.9

1.3

1.1

0.46

0.67 1.8

0.95

0.27 6.6

23.5

0.31

36.0

2600

2100

570

3200

1700

260

1200

670

160

540

800

11 1.9

170 - - - - -

L23

^t3

Cru

st

D10

-1A

14 20.0

0.70 2.3 1.3

0.41

0.39

0.82 2.0

0.88

0.24 7.6

26.1

0.35

39.4

3700

1600

680

4200

1600

410

1300

770

110

610

1000

4.8

2.0

190

250

<4 12 16 4.6

BO

-49

Cru

st

D12

-3A

14 18.0

0.78 3.5 1.3

0.76

0.46

0.80 1.9

0.95

0.29 7.2

26.0

0.35

38.5

3100

1900

580

4200

1600

310

1200

880

130

540

1000

7.3

2.0

170

350

<4 15 19 5.5

BO

-45

Cru

st

D13

-13A

14 17.0

0.82 4.1 1.3

0.65

0.41

0.80 1.8

0.72

0.29 7.0

26.4

0.38

38.6

2800

480

470

4500

1100

340

1200

730

150

510

1400

8.0

2.0

220

240

<4 13 18 5.3

BO

-14

Cru

st

D14

-11

13 17.0

0.76 4.0

1.2

0.81

0.45

0.66 1.8

0.97

0.24 7.8

25.4

0.33

38.1

2900

1200

480

4600

1200

290

1100

870

140

500

1100

7.5

2.5

170 - - - - -

BO

-30

Cru

st

D14

-17A

13.0

15.0

0.87 5.1 1.5

1.3

0.57

0.68 1.8

0.94

0.24 7.4

23.4

0.30

36.2

2600

1700

480

3700

1300

230

1100

920

130

460

1000

9.3

2.3

150 - - - - -

BO

-15

Cru

st

D14

-19A

14.0

18.0

0.78 3.8 1.0

0.73

0.42

0.80 1.9

0.98

0.26 7.3

24.8

0.39

37.4

2900

910

520

4400

1400

340

1200

920

150

500

1200

5.9

2.4

190

220

<4 12 16 4.3

BO

-29

Cru

st

D15

-1A

10.0

16.0

0.63 2.8 1.2

0.61

0.39

0.67 5.8

0.71 1.7

8.1

22.3

0.99

34.8

3300

1000

620

2900

2200

400

1300

1200

210

560

1600

2,8

2,4

140 - - - - -

BO

-29

Cru

st

D15

-1B

7.7

13.0

0.59 1.9

1.0

0.64

0.36

0.73 14 0.62 4.7

5.3

14.9

2.20

26.1

4200

1100

740

1900

2100

290

1400

850

390

440

1200 81 3.7

77 - - - - -B

O-2

0C

rust

Tab

le 6

Con

tinue

d

II D

15-4

AFe

W

t%M

nFe

/Mn

Si Na

Al

K Mg

Ca

Ti

P H2O

+

H2CT

C02

LOI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

2T

ype

11.0

16.0

0.69 2.6 1.1 0.

580.

360.

77 7.2

0.74 2.2

5.8

23.4

1.10

35.3

3300

1000

460

3800

1200

300

1300

690

190

410

1000

9.6

2.2

140

470

<4 18 16 6.3

BO

-93

Cru

st

D15

-4B

13.0

18.0

0.72 3.6

1.4

0.61

0.44

0.83 1.8

0.83

0.26 2.9

28.1

0.34

40.3

3300

670

450

5300

1100

350

1200

680

120

460

1300 10 25 210

220

<4 12 19 5.3

LO

-33

Cru

st

D15

-4C

12.0

20.0

0.60 2.6

0.8

0.62

0.42

0.88 2.0 1.0

0.26 6.8

27.5

0.34

39.9

4100

1400

560

5100

1500

360

1300

830

100

470

1000

9.0

2.5

180

650

<4 29 21 8.3

L 30

-62

Cru

st

D15

-4D

7.4

13.0

0.60 1.5

1.1 0.48

0.34

0.65 14 0.49 4.9

4.0

19.5

2.20

29.9

3100

1100

420

2100

1100

240

1300

640

280

310

680

6.4

2.8

93 590

<4 19 12 7.0

L 62

-95

Cru

st

D18

-1A

11.0

21.0

0.52 2.4

1.1

0.47

0.45

0.90 2.1

0.82

0.29 7.3

27.7

0.36

40.7

4900

1300

550

4900

1300

440

1200

890

170

450

1300

7.3

3.1

190

580

<4 21 19 6.9

BO

-68

Cru

st

D18

-1B

14.0

18.0

0.78 3.4

1.3

0.51

0.40

0.83 1.9

0.77

0.30 6.1

25.4

0.40

38.1

3000

590

440

4300

1100

390

1300

710

160

510

1400

6.2

1.9

230

150

<4 9.6 14 4.4

LO

-18

Cru

st

D18

-1C

9.6

22.0

0.44 1.5

1.0

0.33

0.44

0.93 2.0

0.94

0.23 7.3

28.9

0.34

41.7

5800

1600

590

5900

1400

460

1200

990

140

430

1200

7.3

3.4

170

840

<4 28 23 8.8

L 18

-56

Cru

st

D18

-5A

14.0

16.0

0.88 3.7

1.5

0.58

0.42

0.70 1.9

0.67

0.33 7.6

25.6

0.38

38.3

2700

320

420

4200

9300

360

1200

630

170

560

1400

5.3

2.2

250 - - - - -

BO

-8

Cru

st

D19

-113

.015

.00.

87 5.1 1.3

0.91

0.47

0.64 1.7

0.80

0.28 6.0

24.5

0.34

36.3

2300

520

420

3800

1000

300

1100

760

160

510

1300

4.4

2.1

210 - - - - -

BO

-26

Cru

st

D19

-212

.018

.00.

67 3.8 1.3

0.83

0.51

0.72 1.9

1.0

0.26 5.9

25.5

0.34

38.4

3200

1400

480

4600

1200

280

1100

970

120

490

1400 11 2.9

170 - - - - -

BO

-20

Cru

st

D21

-3A

14.0

14.0

1.00 6.1 1.6

1.3

0.57 1.0

1.8

0.98

0.28 5.1

22.5

0.31

33.9

2100

980

420

3700

1100

210

990

1100

150

470

1300

120

2.3

170 - - - - -

BO

-15

Cru

st

D21

-413

.015

.00.

87 4.4

1.3

0.94

0.48

0.73 1.8

0.94

0.27 7.5

24.9

0.32

37.5

2200

940

410

3700

1000

260

1100

1000

150

490

1300 27 2.0

190 - - - - -

BO

-15

Cru

st

Tab

le 6

Con

tinue

d

II D

22-1

AFe

W

t%M

nF

e/M

nSi N

aA

lK M

gC

aTi P H

2O+

H2a

C02

LOI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

14.0

15.0

0.93 5.6

1.4

1.1 0.53

0.91 1.8

0.74

0.30 6.0

25.2

0.35

36.8

2500

690

380

3700

930

280

1100

630

140

440

1200 30 1.8

220

210

<4 12 17 5.2

BO

-30

Cru

st

D22

-213

.014

.00.

93 5.1 1.3

1.1 0.53

0.71 2.3

0.69

0.35 5.5

25.3

0.98

37.0

2700

520

380

4000

860

260

1000

620

130

460

1200 12 2.4

200 - - - - -

BO

-22

Cru

st

D23

-1A

13.0

17.0

0.76 4.3 1.3

0.81

0.49

0.84 1.9

0.87

0.29 6.6

26.1

0.36

38.2

3300

1100

490

3800

1300

330

1200

1000

150

460

1300

6.3

11 190

440

<4 19 17 6.4

BO

-70

Cru

st

D23

-1B

,C14

.016

.00.

88 5.6

1.3

0.88

0.45

0.76 1.7

0.81

0.27 6.3

25.0

0.36

36.2

2300

640

430

3200

1100

300

1100

840

140

470

1400 11 2.0

200

150

<4 10 15 4.1

LO

-25

Cru

st

D23

-1D

11.0

20.0

0.55 3.0

1.0

0.71

0.51

0.87 2.1

0.96

0.29 6.7

27.5

0.35

39.9

4400

1800

570

4400

1500

360

1100

1200

140

430

1100

5.9

3.0

160

700

<4 27 20 8.6

L 25

-70

Cru

st

D23

-5A

13.0

19.0

0.68 1.6

1.1 0.30

0.32

0.66 5.3

0.89 1.4

6.9

24.3

0.84

36.5

2300

880

570

2300

2600

490

1600

1700

300

600

1900

5.7 1.5

180

520

<4 20 9.9

6.2

BO

^OC

rust

D25

-113

.017

.00.

76 3.6

1.4

0.66

0.47

0.70 1.8

0.86

0.27 6.8

26.0

0.33

39.0

3000

890

470

3600

1200

330

1100

990

160

500

1300

5.5

14 180 - - - - -

BO

-55

Cru

st

D25

-2A

11.0

14.0

0.79 5.6

2.0

1.6

0.85

0.75 1.8

0.82

0.27 6.9

23.1

0.31

35.6

2800

1200

430

3600

1100

240

910

840

140

430

1200 12 2.3

150 - - - - -

BO

-19

Cru

st

D25

-3A

13.0

18.0

0.72 3.5 1.3

0.76

0.48

0.86 2.0

0.93

0.30 6.8

26.5

0.34

39.0

3300

1100

500

3900

1300

340

1100

1100

160

460

1300 11 1.9

180

590

<4 24 16 7.1

BO

-83

Cru

st

D25

-3B

15.0

17.0

0.88 3.8

1.6

0.58

0.40

0.81 1.8

0.88

0.28 7.6

24.7

0.36

37.8

2400

600

450

3600

1100

340

1200

950

160

500

1400

7.2

2.4

210

. 12

0<4 8.

5 15 3.9

LO

-24

Cru

st

D25

-3C

10.0

21.0

0.48 3.0

1.0

0.79

0.53

0.94 11 0.96

0.27 8.0

27.2

0.32

40.1

4800

1800

570

4600

1400

380

1100

1100

150

420

930

23 19 140

650

<4 26 20 8.0

L 24

-46

Cru

st

D25

-3D

11.0

17.0

0.65 4.1 1.1 1.3

0.67

0.87 2.4

0.91

0.43 7.8

26.5

0.36

38.9

3500

1400

520

3000

1800

310

1100

1300

220

420

1200

18.0

1.8

140

1500

<4 55 20 13L

46-8

0C

rust

Tab

le 6

Con

tinue

d

II D

27-1

AF

e W

t%M

nF

e/M

nSi N

aA

lK M

gC

aT

iP H

20+

H20

-

CO

2L

OI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb

Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

2T

ype

13.0

17.0

0.76 12 1.3

0.39

0.31

0.71 4.4

0.89 1.1

6.9

24.9

0.71

37.6

2300

790

510

2700

2200

410

1400

1400

200

550

1500

5.1 1.6

180

400

<4 15 11 5.9

BO

-62

Cru

st

D27

-1B

16.0

17.0

0.94 3.6 1.3

0.55

0.34

0.81 1.7

0.82

0.29 7.3

25.2

0.38

38.4

2400

540

450

3300

1100

300

1200

900

160

490

1300

6.3

2.3

210

210

<4 13 15 5.0

LO

-14

Cru

st

D27

-1C

11.0

16.0

0.69 10 1.2

0.38

0.30

0.60 5.8

0.92

2.00 6.1

23.1

0.95

35.5

2100

910

520

2400

2500

430

1600

1600

230

590

1800

3.4

10 110

350

<4 14 8.8

5.3

L 1

4-51

Cru

st

D27

-412

.015

.00.

80 4.7

1.4

1.4

0.62

0.72 2.0

1.0

0.29 6.4

23.9

0.34

36.8

2700

1300

490

3900

1200

220

980

1000

130

420

1100 12 2.3

130 - - - - -

BO

-18

Cru

st

D27

-5A

12.0

16.0

0.75 2.6

0.9

0.57

0.37

0.68 3.6

0.91

1.00 5.2

26.8

0.60

38.8

2800

1100

520

2900

2200

370

1300

1500

190

540

1500

3.5 1.9

150

640

<4 27 13 8.1

BO

-114

Cru

st

D27

-5B

15.0

14.0

1.07 5.1

0.9

0.85

0.41

0.73 1.6

0.82

0.33 7.9

23.0

0.39

35.3

2000

560

440

3800

1200

250

1200

850

170

510

1400

8.1 1.9

210

120

<4 9.0 15 3.9

LO

-11

Cru

st

D27

-5C

14.0

15.0

0.93 4.7 1.2

0.98

0.50

0.73 1.7

1.10

0.28 7.9

23.9

0.29

35.4

2300

1000

460

3900

1400

210

1200

1100

160

460

1300

9.6

1.8

170

340

<4 20 23 6.5

LI

1-23

Cru

st

D27

-5D

10.0

18.0

0.56 2.9 1.0

0.84

0.49

0.85 1.9

0.84

0.29 5.2

29.1

0.56

40.8

4500

1300

530

3900

1500

280

1100

1100

160

400

1000

7.0

3.1

140

680

<4 33 21 9.2

L 23

-53

Cru

st

D27

-5E

13.0

16.0

0.81 2.1 1.0

0.43

0.32

0.63 3.8

0.94 1.1

5.8

25.4

0.59

37.4

2400

1100

570

2400

2500

450

1500

1700

190

650

1800

5.8 1.7

170

750

<4 32 12 8.7

L 53

-84

Cru

st

D27

-5F

11.0

13.0

0.85 1.9

0.8

0.42

0.29

0.49 9.0

0.90

3.40 5.1

20.5

1.50

31.3

1500

690

490

1700

3000

360

1700

1500

370

560

1500

<2 1.4

110

310

<4 11 6.9

4.4

L 8

3-11

4C

rust

D28

-1A

110

14.0

0.86 6.5 1.2

10 1.1 0.69 1.7

0.90

0.25 7.0

22.9

0.30

33.7

2500

1200

450

3700

1100

200

900

910

130

400

1100 15 14 130 - - - - -

BO

-11

Cru

st

D30

-114

.015

.00.

93 4.7

1.3

0.95

0.49

0.66 1.7

0.83

0.26 8.1

24.2

0.35

37.0

2300

680

460

3800

1100

270

1100

740

150

490

1300

6.3

1.9

200 - - - - -

BO

-21

Cru

st

Tab

le 6

Con

tinue

d

Fe

Wt%

Mn

Fe/

Mn

Si

Na

Al

K Mg

Ca

Ti

P H20

+

H2a

C02

LO

IN

i pp

mC

uZ

nC

oB

aM

oSr C

eY V P

b Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

D31

-1A

110

16.0

0.75 4.6

1.2

1.0

0.51

0.71 10 0.94

0.23 7.6

25.4

0.31

37.5

3100

1100

480

4800

1200

270

1000

760

140

450

1200

6.8

14 170 - - - - -

BO

-45

Cru

st

D32

-213

.018

.00.

72 2.3 1.3

0.37

0.36

0.68 1.8

0.92

0.25 8.0

26.4

0.37

40.1

2500

540

410

4800

1000

370

1100

920

150

530

1300

3.4

2.1

200 - - - - -

BO

-22

Cru

st

D32

-511

.019

.00.

58 3.0

1.0

0.67

0.48

0.76 12 0.86

0.30 7.5

26.8

0.36

39.3

4100

1200

540

3900

1400

380

1100

1100

180

490

1300

3.4

18 170 - - - - -

BO

-72

Cru

st

D32

-6B

14.0

14.0

1.00 7.0

1.5 1.3

0.43

0.85 1.6

0.75

0.30 6.4

22.6

0.32

34.2

2100

1100

500

3000

1100

220

1100

800

120

480

1500

5.5 1.8

200 - - - - -

BO

-3

Cru

st

D32

-8B

12.0

17.0

0.71 4.3 1.3

0.79

0.44

0.76 1.7

0.87

0.29 5.6

24.9

0.35

37.5

3100

900

450

4100

1200

310

1200

920

150

480

1300 12 2.8

180

330

<4 18 19 5.6

BO

^M)

Cru

st

D32

-8C

13.0

13.0

1.00 8.4

1.6

1.4

0.52

0.72 1.6

0.65

0.32 5.2

21.1

0.39

32.0

1800

520

390

2600

1000

230

1100

710

150

470

1400

8.8 1.7

190

140

<4 8.8 14 3.2

LO

-5

Cru

st

D32

-8D

13.0

16.0

0.81 3.9 1.3

0.61

0.39

0.73 1.7

0.90

0.29 4.7

24.6

0.37

37.4

2800

690

430

4000

1200

330

1300

890

170

500

1500

5.4

11 190

160

<4 12 16 4.6

L5-

20C

rust

D32

-8E

11.0

19.0

0.58 2.8 1.1 0.

550.

410.

81 1.9

1.0

0.26 5.1

25.5

0.35

38.5

4200

1300

530

5000

1400

350

1200

1200

140

470

1300

4.2

2.9

170

670

<4 29 22 7.7

L20

^M)

Cru

st

D32

-9C

11.0

17.0

0.65 3.4

1.1

0.75

0.45

0.81 1.9

0.97

0.30 4.3

27.1

0.32

39.4

3700

1300

500

4400

1400

300

1100

1100

170

450

1300

5.6

2.8

160

550

<4 29 23 7.9

BO

-60

Cru

st

D32

-9D

14.0

16.0

0.88 4.6

1.3

0.82

0.41

0.85 1.8

0.67

0.34 7.6

24.4

0.41

36.8

2100

640

460

3000

910

280

1200

910

150

530

1500

3.6

2.2

230 - - - - -

LO

-2

Cru

st

D32

-9E

13.0

18.0

0.72 17 1.1 0.40

0.33

0.76 1.9

0.85

0.31 5.8

25.3

0.39

38.7

3200

850

490

3900

1300

450

1300

830

180

600

1500

4.4

11 210

120

<4 8.6 16 3.7

L2-

17C

rust

D32

-9F

10.0

21.0

0.48 1.5

1.3

0.25

0.35

0.79 2.0

0.98

0.26 6.7

26.9

0.38

40.3

4400

1200

510

4400

1300

480

1300

940

140

540

1400

<2

2.9

170

150

<4 8.8 15 4.1

L 1

7-30

Cru

st

Tab

led

Con

tinue

d

II D

32-9

GFe

W

t%M

nFe

/Mn

Si Na

Al

K MR

Ca

Ti

P H20

+H

2O-

C02

LOI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

9.6

19.0

0.51 2.6

1.0

0.63

0.45

0.82 2.0

0.94

0.28 5.0

27.8

0.30

40.5

4800

1700

580

4700

1600

380

1200

1200

150

460

1100

6.4

3.1

140

700

<4 30 21 8.4

L 3

0-50

Cru

st

D32

-9H

11.0

18.0

0.61 2.7 1.0

0.76

0.46

0.76 2.6

0.90

0.54 4.1

28.3

0.38

40.5

3400

1500

540

2900

2100

330

1200

1500

280

480

1300

3.4

2.1

130

1900

<4 70 21 16L

50-

60C

rust

D33

-1A

13.0

14.0

0.93 6.5 1.9

1.3

0.55

0.86 1.7

0.70

0.28 5.4

23.8

0.34

35.7

2100

740

420

3300

1000

230

1000

750

140

440

1300

8.0

1.7

170 - - - - -

BO

-10

Cru

st

D33

-2A

14.0

13.0

1.08 7.0

1.8

1.30

0.44

0.82 1.6

0.70

0.32 3.8

21.9

0.35

34.0

1800

770

530

2900

1100

230

1100

720

130

470

1400

11.0 1.4

200

180

<4 10 15 4.3

BO

-10

Cru

st

D36

-19.

920

.00.

50 2.1 1.1

0.40

0.42

0.84 3.5

0.79

0.80 6.6

27.3

0.56

39.5

4600

1100

620

4200

1500

450

1300

1100

250

490

1400

4.4

3.0

180 - - - - -

BO

-72

Cru

st

D36

-3A

10.0

17.0

0.59 2.6

1.1 0.46

0.37

0.78 5.0

0.68 1.5

5.2

24.2

0.98

36.4

3800

590

460

3800

1100

390

1300

940

240

450

1400

5.2

2.7

170

470

<4 24 14.

7.1

BO

-78

Cru

st

D36

-3B

13.0

16.0

0.81 4.7 1.0

0.83

0.42

0.76 1.8

0.60

0.39 19 24.2

0.47

35.7

2400

290

340

4000

860

380

1200

680

160

520

1500

<2 1.8

270

200

<4 14 15 5.1

LO

-18

Cru

st

D36

-3C

12.0

18.0

0.67 3.6

1.1

0.65

0.42

0.79 1.7

0.74

0.32 5.9

26.6

0.40

38.7

3300

580

400

4200

1000

370

1200

800

130

480

1500

7.1

3.0

220

360

<4 21 17 6.9

L18

^9C

rust

D36

-3D

7.2

17.0

0.42 1.2

1.3

0.31

0.36

0.77 8.2

0.65 2.8

1.7

23.2

1.50

35.8

4500

930

550

3300

1300

380

1300

1100

320

390

1200 11 2.9

110

730

<4 30 13 8.7

L 1

8-49

Cru

st

D36

^10

.019

.00.

53 2.7 1.2

0.51

0.44

0.83 3.9

0.69 1.0

5.3

27.1

0.63

39.2

4200

630

510

4200

1200

430

1300

1000

200

460

1400 12 2.7

180 - - - - -

BO

-76

Cru

st

D37

-212

.016

.00.

75 4.7 1.3

1.1 0.57

0.82 11 0.98

0.39 5.6

26.0

0.34

38.3

2600

1100

470

4000

1200

270

1100

1200

180

440

1100

6.3

11 150 - - - - -

BO

-50

Cru

st

D37

-4A

13.0

17.0

0.76 3.8

1.1

0.70

0.43

0.78 2.0

0.92

0.37 5.0

24.7

0.45

37.2

2900

1000

480

3400

1300

330

1200

1100

180

500

1200

8.9

2.1

190

290

<4 17 16 5.3

BO

-50

Cru

st

Tab

le 6

Con

tinue

d

H D

37-4

BFe

W

t%M

nF

e/M

nSi N

aA

lK M

gC

aT

iP H

20+

H2O

C0

2L

OI

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

Ir Inte

rval

2T

ype

14.0

16.0

0.88 3.8 1.1 0.

590.

370.

74 1.8

0.92

0.30 5.6

24.2

0.42

36.6

2300

710

480

2900

1300

330

1200

1100

160

530

1400

8.1

2.6

210

140

<4 11 15 3.5

LO

-30

Cru

st

D37

-1C

9.4

17.0

0.55 3.8 1.1 0.

980.

610.

85 3.0

0.88

0.75 3.8

25.7

0.48

37.7

4000

1500

510

3700

1400

330

1100

1200

240

420

870 11 2.8

120

590

<4 30 18 8.0

L 3

0-50

Cru

st

D38

-1A

13.0

17.0

0.76 4.2 1.1 0.

910.

520.

83 12 0.95

0.40 6.3

24.9

0.41

37.4

2900

990

470

3700

1200

330

1200

1200

180

470

1200 28 2.0

170 - - - - -

BO

-55

Cru

st

D38

-1B

14.0

17.0

0.82 3.6

1.0

0.64

0.41

0.79 1.8

0.92

0.28 6.9

26.9

0.36

39.4

2600

580

450

3700

1100

350

1200

1100

160

500

1400

3.2

2.0

200 - - - - -

LO

-28

Cru

st

D38

-1C

10.0

18.0

0.56 4.7

1.0

1.3

0.67

0.90 2.7

0.99

0.54 5.0

26.6

0.39

38.0

3500

1400

490

4100

1200

310

1100

1300

220

410

870

40 2.1

130 - - - - -

L 2

8-57

Cru

st

D38

-2-2

A

11.0

17.0

0.65 5.1 1.6

1.4

0.68

0.88 2.0

0.93

0.33 6.7

23.7

0.31

36.3

3200

1600

520

3700

1200

250

1000

1100

120

410

1100

6.0

2.3

150 - - - - -

BO

-13

Nod

ule

D41

-1A

12.0

16.0

0.75 3.9

1.1 1.0

0.53

0.82 10 0.94

0.34 3.7

25.9

0.34

37.9

3000

1100

440

3500

1200

320

1100

1200

170

450

1100 15 10 160

250

<4 14 15 5.3

BO

-72

Cru

st

D41

-1B

15.0

16.0

0.94 3.2

1.0

0.66

0.35

0.77 1.7

1.0

0.29 6.2

25.6

0.38

38.0

2200

620

430

3400

1200

320

1200

1200

160

520

1400

<2 1.6

210

110

<4 8.6 15 4.0

LO

-32

Cru

st

D41

-1C

9.2

17.0

0.54 4.5 1.3

1.3

0.68

0.92 2.3

0.87

0.39 3.3

26.7

0.31

37.9

3900

1500

450

3500

1200

320

980

1300

170

390

820

4.0

2.8

110

390

<4 20 16 6.7

L 3

2-73

Cru

st

D42

-1A

15.0

15.0

1.00 3.9 1.0

0.66

0.36

0.77 1.7

0.75

0.33 4.6

24.8

0.47

37.1

2100

390

420

3100

1100

330

1200

800

180

530

1500

<2

3.0

230

. 10

0<4 7.

4 12 3.4

BO

-20

Cru

st

D42

-1B

15.0

14.0

1.07 4.1 1.3

0.84

0.43

0.78 1.6

0.75

0.33 5.0

24.7

0.41

37.0

1700

370

390

2900

990

260

1100

850

160

500

1400 11 1.6

220

100

<4 7.4 13 3.1

LO

-7

Cru

st

D42

-1C

14.0

16.0

0.88 3.8

1.0

0.69

0.37

0.77 1.8

0.89

0.31 5.7

25.0

0.45

37.1

2500

590

430

3700

1200

330

1200

870

170

510

1400

7.4

1.8

200

110

<4 9.1 15 3.7

L7-

20C

rust

Maj

or a

nd m

inor

ele

men

ts d

eter

min

ed b

y In

duct

ivel

y C

oupl

ed P

lasm

a-A

tom

ic E

mis

sion

Spe

ctro

met

ry (

ICP-

AE

S),

exce

pt K

, Z

n, P

b by

Fla

me

Ato

mic

Abs

orpt

ion

Spec

tros

copy

, an

d A

s, C

r, C

d by

Gra

phite

-Fur

nace

Ato

mic

Abs

orpt

ion

Spec

tros

copy

; Pt

gro

up e

lem

ents

det

erm

ined

by

ICP

- M

ass

Spec

tros

copy

; Sa

mpl

es w

ere

air

drie

d be

fore

bei

ng g

roun

d; a

naly

sts:

J.

H.

Bul

lock

, W

. M

. d'

Ang

elo,

and

H.

Smith

Sam

ple

num

bers

tha

t ar

e id

entic

al e

xcep

t for

suf

fixe

s -A

, -B

, -C

, -D

, et

c. r

epre

sent

dif

fere

nt s

ampl

e in

terv

als

from

the

sam

e cr

ust

2Int

erva

ls m

easu

red

from

the

out

er s

urfa

ce o

f cr

ust;

B=b

ulk,

whi

ch m

eans

the

ent

ire

crus

t th

ickn

ess

was

sam

pled

and

ana

lyze

d; L

=cru

st l

ayer

Tab

le 7

. H

ygro

scop

ic w

ater

-fre

e (0

% H

2O~)

com

posi

tion

of F

e-M

n cr

usts

fro

m T

able

6

II D

9-11

Fe

Wt%

Mn

Si Na

Al

K Mg

Ca

Ti

P H20

+H

2O-

CO

2N

i pp

mC

uZ

nC

oB

aM

oSr C

eY V P

bC

rC

dA

sPt

pp

bP

d Rh

Ru

Ir Inte

rval

2T

ype

16.4

26.0

3.3 1.6

0.56

0.55

0.93 16 1.21

0.33 8.0

0.0

0.47

5479

945

671

8493

1507

507

1644

890

192

671

1507

13.7

4.5

233 - - - - -

BO

-30

Cru

st

D9-

22A

17.3

21.3

4.7 1.9

1.28

0.65

0.89 2.7

1.08

0.45 9.4

0.0

0.47

4255

2793

758

3856

2261

359

1596

984

173

652

1223

12.8

3.3

226 - - - - -

BO

^lC

rust

D9-

25A

17.4

24.1

4.0 1.7

0.71

0.55

0.88 15 1.18

0.35 11.6

0.0

0.55

4144

1310

615

6818

1471

468

1604

936

214

682

1471

12.2

3.1

254 - - - - -

LO

-23

Cru

st

D9-

25B

19.6

19.6

5.1 1.7

1.44

0.60

0.88 2.4

1.24

0.35 8.6

0.0

0.41

3399

2745

745

4183

2222

340

1569

876

209

706

1046

14.4

2.5

222 - - - - -

L2

3^3

Cru

st

D10

-1A

19.0

27.1

3.1 1.8

0.55

0.53

1.11 2.7

1.19

0.32

10.3

0.0

0.47

5007

2165

920

5683

2165

555

1759

1042

149

825

1353

6.5

2.7

257

338

<5.4

116

.221

.76.

260^9

Cru

st

D12

-3A

18.9

24.3

4.7 1.8

1.03

0.62

1.08 2.6

1.28

0.39 9.7

0.0

0.47

4189

2568

784

5676

2162

419

1622

1189

176

730

1351

9.9

2.7

230

473

<5.4

120

.325

.77.

460^5

Cru

st

D13

-13A

19.0

23.1

5.6

1.8

0.88

0.56

1.09 15 0.98

0.39 9.5

0.0

0.52

3804

652

639

6114

1495

462

1630

992

204

693

1902

10.9

17 299

326

<5.4

317

.724

.57.

2B

O-1

4C

rust

D14

-11

17.4

22.8

5.4

1.6

1.09

0.60

0.88 2.4

1.30

0.32

10.5

0.0

0.44

3887

1609

643

6166

1609

389

1475

1166

188

670

1475

10.1

3.4

228 - - - - -

BO

-30

Cru

st

D14

-17A

17.0

19.6

6.7

2.0

1.70

0.74

0.89 2.4

1.23

0.31 9.7

0.0

0.39

3394

2219

627

4830

1697

300

1436

1201

170

601

1305

12.1

3.0

196 - - - - -

BO

-15

Cru

st

D14

-19A

18.6

24.0

5.1 1.3

0.97

0.56

1.06 2.5

1.30

0.35 9.7

0.0

0.52

3856

1210

691

5851

1862

452

1596

1223

199

665

1596

7.9

3.2

253

293

<5.3

216

.021

.35.

7B

O-2

9C

rust

D15

-1A

12.9

20.6

3.6 1.5

0.79

0.50

0.86 7.5

0.91

2.19

10.4

0.0

1.27

4247

1287

798

3732

2831

515

1673

1544

270

721

2059

3.6

3.1

180 - - - - -

BO

-29

Cru

st

D15

-1B

9.1

15.3

2.2

1.1 0.75

0.42

0.86

16.5

0.73

5.52 6.2

0.0

2.59

4935

1293

870

2233

2468

341

1645

999

458

517

1410

95.2

4.4 90 - - - - -

BO

-20

Cru

st

Tab

le?

Con

tinue

d

Fe

Wt%

Mn

Si Na

Al

K Mg

Ca

Ti

P H2O

+H

20-

CO

2N

i pp

mC

uZ

nC

oB

aM

oSr C

eY V P

bC

rC

dA

sPt

pp

bP

d Rh

Ru

fr Inte

rval

2T

ype

DIS

^A14

.420

.93.

41.

40.

760.

471.

01 9.4

0.97

2.87 7.6

0.0

1.44

4308

1305

601

4961

1567

392

1697

901

248

535

1305

12.5

2.9

183

614

<5.2

223

.520

.98.

2B

O-9

3C

rust

D15

-4B

18.1

25.0

5.0

1.9

0.85

0.61 1.15 2.5

1.15

0.36 4.0

0.0

0.47

4590

932

626

7371

1530

487

1669

946

167

640

1808

13.9

3.5

292

306

<5.5

616

.726

.47.

4L

O-3

3C

rust

D15

-4C

16.6

27.6

3.6

1.1 0.86

0.58 1.21 18 1.38

0.36 9.4

0.0

0.47

5655

1931

772

7034

2069

497

1793

1145

138

648

1379

12.4

3.4

248

897

<5.5

240

.029

.011

.4L

30-

62C

rust

D15

-4D

9.2

16.1 1.9

1.4

0.60

0.42

0.81 17.4

0.61

6.09 5.0

0.0

2.73

3851

1366

522

2609

1366

298

1615

795

348

385

845

8.0

3.5

116

733

<4.9

723

.614

.98.

7L

62-

95C

rust

D18

-1A

15.2

29.0

3.3

1.5

0.65

0.62

1.24 2.9

1.13

0.40

10.1

0.0

0.50

6777

1798

761

6777

1798

609

1660

1231

235

622

1798

10.1

4.3

263

802

<5.5

329

.026

.39.

5B

O-6

8C

rust

D18

-1B

18.8

24.1

4.6

1.7

0.68

0.54

1.11 2.5

1.03

0.40 8.2

0.0

0.54

4021

791

590

5764

1475

523

1743

952

214

684

1877

8.3

2.5

308

201

<5.3

612

.918

.85.

9L

O-1

8C

rust

D18

-1C

13.5

30.9

11 1.4

0.46

0.62

1.31 18 1.32

0.32

10.3

0.0

0.48

8158

2250

830

8298

1969

647

1688

1392

197

605

1688

10.3

4.8

239

1181

<5.6

339

.432

.312

.4L

18-

56C

rust

D18

-5A

18.8

21.5

5.0

2.0

0.78

0.56

0.94 2.6

0.90

0.44

10.2

0.0

0.51

3629

430

565

5645

1250

048

416

1384

722

875

318

827.

13.

033

6 - - - - -B

O-8

Cru

st

D19

-117

.219

.96.

81.

71.

210.

620.

85 2.3

1.06

0.37 7.9

0.0

0.45

3046

689

556

5033

1325

397

1457

1007

212

675

1722

5.8

2.8

278 - - - - -

BO

-26

Cru

st

D19

-216

.124

.25.

1 1.7

1.11

0.68

0.97 2.6

1.34

0.35 7.9

0.0

0.46

4295

1879

644

6174

1611

376

1477

1302

161

658

1879

14.8

3.9

228 -

.- - -

BO

-20

Cru

st

D21

-3A

18.1

18.1

7.9

11 1.68

0.74

1.29 13 1.26

0.36 6.6

0.0

0.40

2710

1265

542

4774

1419

271

1277

1419

194

606

1677

154.

83.

021

9 - - - - -B

O-1

5C

rust

D21

-417

.320

.05.

91.

71.

250.

640.

97 2.4

1.25

0.36

10.0

0.0

0.43

2929

1252

546

4927

1332

346

1465

1332

200

652

1731

36.0

2.7

253 - - - - -

BO

- 15

Cru

st

Tab

le?

Con

tinue

d

JL

D22

-1A

Fe

Wt%

Mn

Si Na

Al

K Mg

Ca

Ti

P H20

+H

20-

C02

Ni

ppm

Cu

Zn

Co

Ba

Mo

Sr Ce

Y V Pb

Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

18.7

20.1

7.5 1.9

1.47

0.71 1.22 2.4

0.99

0.40 8.0

0.0

0.47

3342

922

508

4947

1243

374

1471

842

187

588

1604

40.1 2.4

294

281

<5.3

516

.022

.77.

0B

O-3

0C

rust

D22

-217

.418

.76.

8 1.7

1.47

0.71

0.95 3.1

0.92

0.47 7.4

0.0

1.31

3614

696

509

5355

1151

348

1339

830

174

616

1606

16.1

3.2

268 - - - - -

BO

-22

Cru

st

D23

-1A

17.6

23.0

5.8 1.8

1.10

0.66

1.14 16 1.18

0.39 8.9

0.0

0.49

4465

1488

663

5142

1759

447

1624

1353

203

622

1759 8.5

18 257

595

<5.4

125

.723

.08.

7B

O-7

0C

rust

D23

-1B

.C18

.721

.37.

5 1.7

1.17

0.60

1.01 13 1.08

0.36 8.4

0.0

0.48

3067

853

573

4267

1467

400

1467

1120

187

627

1867

14.7

2.7

267

200

<5.3

313

.320

.05.

5L

O-2

5C

rust

D23

-1D

15.2

27.6

4.1 1.4

0.98

0.70

1.20 2.9

1.32

0.40 9.2

0.0

0.48

6069

2483

786

6069

2069

497

1517

1655

193

593

1517

8.1

4.1

221

966

<5.5

237

.227

.611

.9L

25-

70C

rust

D23

-5A

17.2

25.1 2.1 1.5

0.40

0.42

0.87 7.0

1.18

1.85 9.1

0.0

1.11

3038

1162

753

3038

3435

647

2114

2246

396

793

2510 7.5

2.0

238

687

<5.2

826

.413

.18.

2B

O^O

Cru

st

D25

-117

.623

.04.

9 1.9

0.89

0.64

0.95 14 1.16

0.36 9.2

0.0

0.45

4054

1203

635

4865

1622

446

1486

1338

216

676

1757

7.4

3.2

243 - - - - -

BO

-55

Cru

st

D25

-2A

14.3

18.2

7.3

2.6

2.08

1.11

0.98 2.3

1.07

0.35 9.0

0.0

0.40

3641

1560

559

4681

1430

312

1183

1092

182

559

1560

15.6

3.0

195 - - - - -

BO

-19

Cru

st

D25

-3A

17.7

24.5

4.8 1.8

1.03

0.65

1.17 2.7

1.27

0.41 9.3

0.0

0.46

4490

1497

680

5306

1769

463

1497

1497

218

626

1769

15.0

2.6

245

803

<5.4

432

.721

.89.

7B

O-8

3C

rust

D25

-3B

19.9

22.6

5.0

2.1

0.77

0.53

1.08 2.4

1.17

0.37

10.1

0.0

0.48

3187

797

598

4781

1461

452

1594

1262

212

664

1859

9.6

3.2

279

159

. <5

.31

11.3

19.9

5.2

LO

-24

Cru

st

D25

-3C

13.7

28.8

4.1 1.4

1.09

0.73 1.29 19 1.32

0.37

11.0

0.0

0.44

6593

2473

783

6319

1923

522

1511

1511

206

577

1277

31.6

4.0

192

893

<5.4

935

.727

.511

.0L

24^6

Cru

st

D25

-3D

15.1

23.4

5.6

1.5

1.79

0.92

1.20 3.3

1.25

0.59

10.7

0.0

0.49

4808

1923

714

4121

2473

426

1511

1786

302

577

1648

24.7

2.5

192

2060

<5.4

975

.527

.517

.9L

46-

80C

rust

Tab

le 7

Con

tinue

d

|| D

27-1

AFe

W

t%M

nSi N

aA

lK M

gC

aT

iP H

2O+

H20

-

CO

2N

i pp

mC

uZ

nC

oB

aM

oSr C

eY V P

bC

rC

dA

sPt

pp

bPd R

hR

ufr In

terv

al2

Typ

e

17.3

22.6

2.9 1.7

0.52

0.41

0.95 5.9

1.19

1.46 9.2

0.0

0.95

3063

1052

679

3595

2929

546

1864

1864

266

732

1997

6.8

2.1

240

533

<5.3

320

.014

.67.

9B

O-6

2C

rust

D27

-1B

21.4

22.7

4.8 1.7

0.74

0.45 1.08 2.3

1.10

0.39 9.8

0.0

0.51

3209

722

602

4412

1471

401

1604

1203

214

655

1738

8.4

3.1

281

281

<5.3

517

.420

.16.

7L

O-1

4C

rust

D27

-1C

14.3

20.8

16 1.6

0.49

0.39

0.78 7.5

1.20

2.60 7.9

0.0

1.24

2731

1183

676

3121

3251

559

2081

2081

299

767

2341 4.4

16 143

455

<5.2

018

.211

.46.

9L

14-

51C

rust

D27

-415

.819

.76.

21.

81.

840.

810.

95 2.6

1.31

0.38 8.4

0.0

0.45

3548

1708

644

5125

1577

289

1288

1314

171

552

1445

15.8

3.0

171 - - - - -

BO

-18

Cru

st

D27

-5A

16.4

21.9

3.6

1.2

0.78

0.51

0.93 4.9

1.24

1.37 7.1

0.0

0.82

3825

1503

710

3962

3005

505

1776

2049

260

738

2049

4.8

2.6

205

874

<5.4

636

.917

.811

.1B

O-1

14C

rust

D27

-5B

19.5

18.2

6.6

1.2

1.10

0.53

0.95 2.1

1.06

0.43

10.3

0.0

0.51

2597

727

571

4935

1558

325

1558

1104

221

662

1818

10.5

2.5

273

156

<5.1

911

.719

.55.

1L

O-1

1C

rust

D27

-5C

18.4

19.7

6.2 1.6

1.29

0.66

0.96 12 1.45

0.37

10.4

0.0

0.38

3022

1314

604

5125

1840

276

1577

1445

210

604

1708

12.6

14 223

447

<5.2

626

.330

.28.

5L

I 1-

23C

rust

D27

-5D

14.1

25.4

4.1 1.4

1.18

0.69

1.20 2.7

1.18

0.41 7.3

0.0

0.79

6347

1834

748

5501

2116

395

1551

1551

226

564

1410

9.9

4.4

197

959

<5.6

446

.529

.613

.0L

23-

53C

rust

D27

-5E

17.4

21.4

2.8

1.3

0.58

0.43

0.84 5.1

1.26

1.47 7.8

0.0

0.79

3217

1475

764

3217

3351

603

2011

2279

255

871

2413

7.8

2.3

228

1005

<5.3

642

.916

.111

.7L

53-

84C

rust

D27

-5F

13.8

16.4

2.4

1.0

0.53

0.36

0.62

11.3

1.13

4.28 6.4

0.0

1.89

1887

868

616

2138

3774

453

2138

1887

465

704

1887

2.5 1.8

138

390

<5.0

313

.88.

75.

5L

83-

1 14

Cru

st

D28

-1A

15.6

18.2

8.4

1.6

2.59

1.43

0.89 12 1.17

0.32 9.1

0.0

0.39

3243

1556

584

4799

1427

259

1167

1180

169

519

1427

19.5

3.1

169 - - - - -

BO

-11

Cru

st

D30

-118

.519

.86.

21.

71.

250.

650.

87 2.2

1.09

0.34

10.7

0.0

0.46

3034

897

607

5013

1451

356

1451

976

198

646

1715

8.3

2.5

264 - - - - -

BO

-21

Cru

st

Tab

le?

Con

tinue

d

Fe

Wt%

Mn

Si Na

Al

K Mg

Ca

Ti P H2O

+H

2O-

CO

2N

i pp

mC

uZ

n Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As

Pt

ppb

Pd Rh

Ru

IT Inte

rval

2T

ype

D31

-1A

16.1

21.4

6.2

1.6

1.34

0.68

0.95 2.7

1.26

0.31 10.2

0.0

0.42

4155

1475

643

6434

1609

362

1340

1019

188

603

1609

9.1

3.2

228 - - - - -

BO

-45

Cru

st

D32

-216

.321

.76.

3 1.6

1.36

0.69

0.96 2.7

1.28

0.31 10.3

0.0

0.42

4212

1495

652

6522

1630

367

1359

1033

190

611

1630

9.2

3.3

231 - - - - -

BO

-22

Cru

st

D32

-515

.026

.04.

1 1.4

0.92

0.66

1.04 3.0

1.17

0.41 10.2

0.0

0.49

5601

1639

738

5328

1913

519

1503

1503

246

669

1776

4.6

3.8

232 - - - - -

BO

-72

Cru

st

D32

-6B

18.1

18.1

9.0

1.9

1.68

0.56

1.10 2.1

1.03

0.39 8.3

0.0

0.41

2713

1421

646

3876

1421

284

1421

1034

155

620

1938

7.1

2.3

258 - - - - -

BO

-3

Cru

st

D32

-8B

16.0

22.6

5.7

1.7

1.05

0.59

1.01 2.3

1.16

0.39 7.5

0.0

0.47

4128

1198

599

5459

1598

413

1598

1225

200

639

1731

16.0

3.7

240

439

<5.3

324

.025

.37.

5B

O-4

0C

rust

D32

-8C

16.5

16.5

10.6

2.0

1. 77

0.66

0.91 2.0

0.82

0.41 6.6

0.0

0.49

2281

659

494

3295

1267

292

1394

900

190

596

1774

11.2

2.2

241

177

<5.0

711

.217

.74.

1L

O-5

Cru

st

D32

-8D

17.2

21.2

5.2 1.7

0.81

0.52

0.97 13 1.19

0.38 6.2

0.0

0.49

3714

915

570

5305

1592

438

1724

1180

225

663

1989

7.2

18 252

212

<5.3

115

.921

.26.

1L

5-20

Cru

st

D32

-8E

14.8

25.5

3.8

1.5

0.74

0.55

1.09 2.6

1.34

0.35 6.8

0.0

0.47

5638

1745

711

6711

1879

470

1611

1611

188

631

1745

5.6

3.9

228

899

<5.3

738

.929

.510

.3L

20-

40C

rust

D32

-9C

15.1

23.3

4.7 1.5

1.03

0.62

1.11 2.6

1.33

0.41 5.9

0.0

0.44

5075

1783

686

6036

1920

412

1509

1509

233

617

1783

7.7

3.8

219

754

<5.4

939

.831

.610

.8B

O-6

0C

rust

D32

-9D

18.5

21.2

6.1 1.7

1.08

0.54

1.12 2.4

0.89

0.45

10.1

0.0

0.54

2778

847

608

3968

1204

370

1587

1204

198

701

1984

4.8

2.9

304 -

.- - -

LO

-2

Cru

st

D32

-9E

17.4

24.1

3.6 1.5

0.54

0.44

1.02 15 1.14

0.41 7.8

0.0

0.52

4284

1138

656

5221

1740

602

1740

1111

241

803

2008

5.9

18 281

161

<5.3

511

.521

.45.

0L

2-17

Cru

st

D32

-9F

13.7

28.7

2.1 1.8

0.34

0.48

1.08 2.7

1.34

0.36 9.2

0.0

0.52

6019

1642

698

6019

1778

657

1778

1286

192

739

1915

2.7

4.0

233

205

<5.4

712

.020

.55.

6L

17-

30C

rust

Tab

le?

Con

tinue

d

J| D

32-9

GFe

W

t%M

nSi N

aA

lK M

gC

aT

iP H

2O+

H20

-

CO

2N

i pp

mC

uZ

nC

oB

aM

oSr C

eY V Pb C

rC

dA

sPt

pp

bP

d Rh

Ru

fr Inte

rval

^T

ype

13.3

26.3

3.6

1.4

0.87

0.62

1.14 2.8

1.30

0.39 6.9

0.0

0.42

6648

2355

803

6510

2216

526

1662

1662

208

637

1524

8.9

4.3

194

970

<5.5

441

.629

.111

.6L

30-

50C

rust

D32

-9H

15.3

25.1 3.8 1.4

1.06

0.64 1.06 3.6

1.26

0.75 5.7

0.0

0.53

4742

2092

753

4045

2929

460

1674

2092

391

669

1813

4.7

2.9

181

2650

<5.5

897

.629

.322

.3L

50-

60C

rust

D33

-1A

17.1

18.4

8.5

2.5

1.71

0.72

1.13 2.2

0.92

0.37 7.1

0.0

0.45

2756

971

551

4331

1312

302

1312

984

184

577

1706

10.5

2.2

223 - - - - -

BO

-10

Cru

st

D33

-2A

17.9

16.6

9.0

2.3

1.66

0.56

1.05 2.0

0.90

0.41 4.9

0.0

0.45

2305

986

679

3713

1408

294

1408

922

166

602

1793

14.1 1.8

256

230

<5.1

212

.819

.25.

5B

O-1

0C

rust

D36

-113

.627

.52.

91.

50.

550.

581.

16 4.8

1.09

1.10 9.1

0.0

0.77

6327

1513

853

5777

2063

619

1788

1513

344

674

1926

6.1

4.1

248 - - - - -

BO

-72

Cru

st

D36

-3A

13.2

22.4

3.4

1.5

0.61

0.49

1.03 6.6

0.90

1.98 6.9

0.0

1.29

5013

778

607

5013

1451

515

1715

1240

317

594

1847

6.9

3.6

224

620

<5.2

831

.718

.59.

4B

O-7

8C

rust

D36

-3B

17.2

21.1

6.2 1.3

1.09

0.55 1.00 2.4

0.79

0.51 3.8

0.0

0.62

3166

383

449

5277

1135

501

1583

897

211

686

1979

2.6

2.4

356

264

<5.2

818

.519

.86.

7L

O-1

8C

rust

D36

-3C

16.3

24.5

4.9 1.5

0.89

0.57

1.08 2.3

1.01

0.44 8.0

0.0

0.54

4496

790

545

5722

1362

504

1635

1090

111

654

2044

9.7

4.1

300

490

<5.4

528

.623

.29.

4L

18^9

Cru

st

D36

-3D

9.4

22.1 1.6

1.7

0.40

0.47

1.00

10.7

0.85

3.65 2.2

0.0

1.95

5859

1211

716

4297

1693

495

1693

1432

417

508

1563

14.3

3.8

143

951

<5.2

139

.116

.911

.3L

18-

49C

rust

D36

^13

.726

.1 3.7

1.6

0.70

0.60

1.14 5.3

0.95

1.37 7.3

0.0

0.86

5761

864

700

5761

1646

590

1783

1372

274

631

1920

16.5

3.7

247 -

.- - -

BO

-76

Cru

st

D37

-216

.221

.66.

41.

81.

490.

771.

11 2.8

1.32

0.53 7.6

0.0

0.46

3514

1486

635

5405

1622

365

1486

1622

243

595

1486

8.5

2.8

203 - - - - -

BO

-50

Cru

st

D37

^A17

.322

.65.

01.

50.

930.

571.

04 2.7

1.22

0.49 6.6

0.0

0.60

3851

1328

637

4515

1726

438

1594

1461

239

664

1594

11.8

2.8

252

385

<5.3

122

.621

.27.

0B

O-5

0C

rust

Tab

le?

Con

tinue

d

Fe

Wt%

Mn

Si Na

Al

K Mg

Ca

Ti

P H20

+H

20-

CO

2N

i pp

mC

uZ

nC

oB

aM

oSr C

eY V P

b Cr

Cd

As

Pt

ppb

Pd Rh

Ru

fr Inte

rval

^T

ype

D37

-4B

18.5

21.1

5.0

1.5

0.78

0.49

0.98 2.4

1.21

0.40 7.4

0.0

0.55

3034

937

633

3826

1715

435

1583

1451

211

699

1847

10.7

3.4

277

185

<5.2

814

.519

.84.

6L

O-3

0C

rust

D37

-4C

12.7

22.9

5.1 1.5

1.32

0.82

1.14 4.0

1.18

1.01 5.1

0.0

0.65

5384

2019

686

4980

1884

444

1480

1615

323

565

1171

14.8

3.8

162

794

<5.3

840

.424

.210

.8L

30-

50C

rust

D38

-1A

17.3

22.6

5.6 1.5

1.21

0.69

1.11 19 1.26

0.53 8.4

0.0

0.55

3862

1318

626

4927

1598

439

1598

1598

240

626

1598

37.3

17 226 - - - - -

BO

-55

Cru

st

D38

-1B

19.2

23.3

4.9

1.3

0.88

0.56

1.08 2.5

1.26

0.38 9.4

0.0

0.49

3557

793

616

5062

1505

479

1642

1505

219

684

1915

4.4

2.7

274 - - - - -

LO

-28

Cru

st

D38

-1C

19.1

21.8

5.2

1.5

0.80

0.50

1.01 2.5

1.25

0.41 7.6

0.0

0.57

3134

967

654

3951

1771

450

1635

1499

218

722

1907

11.0

3.5

286 - - - - -

L 2

8-57

Cru

st

D38

-2-2

A

14.4

22.3

6.7

2.1

1.83

0.89

1.15 2.6

1.22

0.43 8.8

0.0

0.41

4194

2097

682

4849

1573

328

1311

1442

157

537

1442

7.9

3.0

197 - - - - -

BO

-13

Nod

ule

D41

-1A

16.2

21.6

5.3 1.5

1.35

0.72

1.11 17 1.27

0.46 5.0

0.0

0.46

4049

1484

594

4723

1619

432

1484

1619

229

607

1484

20.2

17 216

337

<5.4

018

.920

.27.

2B

O-7

2C

rust

D41

-1B

20.2

21.5

4.3 1.3

0.89

0.47

1.03 2.3

1.34

0.39 8.3

0.0

0.51

2957

833

578

4570

1613

430

1613

1613

215

699

1882

2.7

2.2

282

148

<5.3

811

.620

.25.

4L

O-3

2C

rust

D41

-1C

12.6

23.2

6.1 1.8

1.77

0.93

1.26 3.1

1.19

0.53 4.5

0.0

0.42

5321

2046

614

4775

1637

437

1337

1774

232

532

1119

5.5

3.8

150

532

<5.4

627

.321

.89.

1L

32-

73C

rust

D42

-1A

19.9

19.9

5.2

1.3

0.88

0.48

1.02 2.3

1.00

0.44 6.1

0.0

0.63

2793

519

559

4122

1463

439

1596

1064

239

705

1995

2.7

4.0

306

133

. <5

.32

9.8

16.0

4.5

BO

-20

Cru

st

D42

-1B

19.9

18.6

5.4

1.7

1.12

0.57

1.04 11 1.00

0.44 6.6

0.0

0.54

2258

491

518

3851

1315

345

1461

1129

212

664

1859

14.6

2.1

292

133

<5.3

19.

817

.34.

1L

O-7

Cru

st

D42

-1C

18.7

21.3

5.1 1.3

0.92

0.49

1.03 2.4

1.19

0.41 7.6

0.0

0.60

3333

787

573

4933

1600

440

1600

1160

227

680

1867

9.9

2.4

267

147

<5.3

312

.120

.04.

9L

7-20

Cru

st

Table 8. Statistics for 46 bulk Fe-Mn crusts from Tunes 6 cruise; data from table 6

ElementFe Wt %MnFe/Mn4SiNaAlKMgCaTiPH20+H20-

C02LOI

Ni ppmCuZnCoBaMoSrCeYVPbCrCdAs

Pt ppbPdRhRuIr

Depth5Thickness**

N464646464646464646464646464646

4646464646464646464646454646

1919191919

4646

Mean12.416.50.774.01.30.90.480.772.70.850.576.424.80.4837.2

299310164933802149831611589501664831270132.0176

373<417.215.95.8

145040

Median13.016.50.763.91.30.80.460.771.90.880.306.624.90.3537.5

2900100048038001200310110092015048013007

2.3175

350<417.016.05.6

723859

SD1

1.461.910.131.40.20.40.130.082.10.110.761.12.10.332.4

702380737391235701352305047183200.529

15905.93.11.3

226126

Min2

7.713.00.501.60.90.30.310.641.60.620.233.714.90.3026.1

1800320380190086020090062011040092021.477

100<47.49.93.4

14503

Max3

15.021.01.087.02.02.01.101.0014.01.004.708.127.72.2040.7

49002100740620093004901600170039061019001208.1250

640<429.023.08.1

13025114

1 Standard deviation; 2Minimum; 3 Maximum; 4 Ratio of the Fe and Mn means, not a mean of the summation of ratios; 5 Water depth in meters; 6Crust thickness in millimeters

37

Table 9. Statistics for 46 bulk Fe-Mn crusts from Tunes 6 cruise; data from table 7 (hygroscopic water-free)

ElementFe Wt%MnSiNaAlKMgCaTiPH20+

C02

Ni ppmCuZnCoBaMoSrCeYVPbCrCdAs

Pt ppbPdRhRuIr

Depth4

Thickness5

N4646464646464646464646 46

4646464646464646464646464646

1919191919

4646

Mean16.722.15.41.71.150.651.023.21.140.638.6 0.59

399213696525177197842215381260215645168915.33.1237

501<5.3623.221.37.8

1450 40

Median17.222.15.31.71.070.621.022.61.180.409.0 0.47

387513236435023161041615061224202635171110.13.0236

473<5.3522.621.37.5

7238 59

SD1

1.72.81.70.30.460.170.111.60.140.581.6 0.28

960499861002165698183315506524522.50.634

2180.108.14.41.8

2261 26

Min2

12.916.62.11.20.400.410.852.00.900.314.9 0.39

230543050830381151259116783014951912232.71.8169

133<5.129.813.14.5

1450 3

Max3

19.929.09.02.62.591.431.299.41.342.8711.6 1.44

67772793920849312500647211422463968252510154.84.5336

874<5.5339.831.611.1

13025 114

1 Standard deviation; 2Minimum; 3 Maximum; 4Ratio of the Fe and Mn means, not a mean of the summation of ratios; 5 Water depth in meters; 6Crust thickness in millimeters

38

Table 10. Statistics for 38 Fe-Mn crust layers from the Tunes 6 cruise; data from table 7 (hygroscopic water-free)

ElementFe Wt. %MnFe/Mn4SiNaAlKMgCaTiPH20+C02

Ni ppmCuZnCoBaMoSrCeYVPbCrCdAs

Pt ppbPdRhRuIr

N38383838383838383838383838

3838383838383838383838383838

3333333333

Mean16.222.60.74.61.50.930.571.044.01.150.997.70.73

420913326544837188745316391374243647172212.13.2233

612<5.3627.722.28.7

Median16.922.40.84.91.50.880.551.052.51.190.417.80.52

37831161630485717284511612133921465918169.73.0240

447<5.3618.520.57.4

SD1

3.23.60.21.80.20.360.130.153.70.191.452.10.58

1492641100138060392163366788633215.00.861

5660.219.65.74.1

Min2

9.115.30.41.61.00.340.360.622.00.610.322.20.38

18873834492138113527613377951383858452.51.890

133<4.979.88.74.1

Max3

21.430.91.110.62.11.790.931.3117.41.456.0911.02.73

815827458708298377465721382279465871241395.24.8356

2650<5.6497.632.322.3

1 Standard deviation; 2Minimum; 3 Maximum; 4 Ratio of the Fe and Mn means, not a mean of the summation of ratios

39

Tab

le 1

1. C

once

ntra

tions

of r

are

eart

h el

emen

ts (

ppm

) in

Fe-

Mn

crus

ts f

rom

the

Tun

es 6

cru

ise

La Ce

Pr Nd

Sm Eu

Gd

Tb

Dv

Ho

Er

Tm

Yb

2RE

EC

e*

Inte

rval

D10

-1A

320

980

59 230

46 10.0

44 7.4

42 8.4

23 3.4

20 1793

1.61

BO

-49

D 1

2-3 A

320

1100 62 240

48 11.0

50 7.9 46 9.3 25 3.7 23 1946

1.78

B0

^5

D13

-3A

260

790

44 180

36 8.6 40 6.6 39 8.6 23 3.5 21 1460

1.64

BO

- 14

D 1

4- 19

A36

011

00 71 280

58 13.0

55 9.1 54 11.0

29 4.3 27 2071

1.57

BO

-29

D15

^A25

065

040 16

032 7.

3 36 5.7 35 7.9 24 3.5 21 1272

1.43

BO

-93

D15

-4B

310

840

54 220

43 9.8 45 7.3 44 8.9 25 3.7 22 1633

1.45

L0

^3

D15

-4C

230

980

42 170

33 7.3 33 5.4 33 6.6 19 2.8 17 1579

2.25

L 3

0-62

D15

-4D

240

810

32 130

24 5.9 31 4.8 33 8.1 25 3.7 24 1372

1.95

L 6

2-95

D18

-1A

320

1000 60 240

47 11.0

50 8.0 49 10.0

28 4.0 25 1852

1.63

BO

-68

D18

-1B

310

710

58 240

47 11.0

50 8.4 49 10.0

27 3.9 24 1548

1.20

LO

-18

D18

-1C

280

1300 55 210

44 10.0

43 7.4

42 8.5

24 3.6

22 2050

2.39

L 1

8-56

D22

-1A

290

780

55 220

45 10.0

47 7.7 47 9.3 27 3.8 23 1565

1.40

BO

-30

D23

-1A

290

1100 57 230

48 11.0

48 8.0 47 9.1 25 3.7 22 1899

1.95

BO

-70

La

Ce

Pr Nd

Sm Eu

Gd

Tb

Dv

Ho

Er

Tm

Yb

2RE

EC

e*

Inte

rval

D23

-1B

.C30

096

059 23

047 11

.050 8.

348 9.

526 3.

823 17

761.

65

LO

-25

D23

-1D

280

1400 54 210

44 10.0

44 7.1 43 8.6 25 3.6 22 2151

2.59

L 2

5-70

D23

-5A

540

2000 77 290

51 12.0

58 9.0 56 12.0

34 5.0 30 3174

2.11

BO

-40

D25

-3A

320

1300 65 250

53 12.0

53 8.5 50 9.7 26 3.8 22 2173

2.07

BO

-83

D25

-3C

310

1400 65 260

55 12.0

49 8.4 51 9.7 27 3.9 23 2274

2.27

L 2

4-46

D25

-3D

420

1700 82 320

65 15.0

66 9.8 59 11.0

31 4.3 25 2808

2.09

L 4

6-80

D27

-1A

430

1500 72 280

52 12.0

57 8.8 54 11.0

31 4.4 26 2538

1.89

BO

-62

D27

-1B

360

1100 70 270

57 13.0

59 9.6 58 11.0

30 4.3 26 2068

1.58

LO

-14

D27

-1C

430

1900 68 260

47 12.0

51 7.8 48 11.0

31 4.3 27 2897

2.44

L 1

4-51

D27

-5A

410

2200 65 260

48 11.0

52 7.9 47 10.0

29 4.0 24 3168

2.96

BO

-114

D27

-5B

270

920

53 220

47 12.0

54 8.5

50 9.9

27 3.8

23 1698

1.75

LO-1

1

D27

-5C

280

1100

52 210

43 11.0

47 7.5 46 9.5 27 3.8 24 1861

2.06

LI

1-23

D27

-5D

260

1600 48 200

39 10.0

41 6.8 41 8.6 23 3.5 22 2303

3.24

L 2

3-53

Tab

le 1

1 C

ontin

ued

La Ce

Pr Nd

Sm Eu Gd

Tb

Dv

Ho

Er

Tm

Yb

ZR

EE

Ce*

Inte

rval

D27

-5E

370

2100 63 240

44 11.0

48 7.2

44 8.8

25 3.6

22 2987

3.06

L 5

3-84

D27

-5F

500

2400 73 280

50 12.0

61 9.0 60 14.0

39 5.5 35 3539

2.71

L 83

- 114

D32

-8B

260

1100

49 200

41 10.0

47 7.3 45 8.9 24 3.4 22 1818

2.21

BO

^tt)

D32

-8C

240

820

47 190

41 11.0

46 7.5 45 9.2 24 3.3 21 1505

1.76

LO-5

D32

-8D

330

1100 63 250

51 13.0

59 9.6 55 12.0

29 4.3 27 2003

1.73

L5-

20

D32

-8E

270

1600 52 200

43 11.0

41 7.1 42 9.3 26 3.7 24 2329

3.07

L20

^M)

D32

-9C

330

1500 66 260

55 14.0

57 9.5 54 11.0

29 4.2 26 2416

2.33

BO

-60

D32

-9D

280

1000 59 240

51 13.0

56 9.0 51 10.0

26 3.7 23 1822

1.79

LO

-2

D32

-9E

370

1100 77 300

64 17.0

68 11.0

64 13.0

35 5.1 30 2154

1.50

L2-

17

D32

-9F

320

1200 69 260

58 15.0

53 9.5 55 11.0

30 4.2 27 2113

1.87

L 17

-30

D32

-9G

240

1500

48 180

39 10.0

38 6.5

38 8.0

23 3.4

20 2154

3.20

L 3

0-50

D32

-9H

400

1700 80 320

62 17.0

71 11.0

62 13.0

35 4.8 29 2805

2.17

L 5

0-60

D33

-2A

240

790

46 180

38 11.0

41 7.0 39 7.9 22 3.3 20 1445

1.71

BO

-10

La Ce

Pr Nd

Sm Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

ZR

EE

Ce*

Inte

rval

D36

-3A

290

1200

49 200

41 11.0

47 7.8

45 10.0

29 4.2

25 1959

2.24

BO

-78

D36

-3B

280

780

51 200

42 12.0

50 8.3 48 9.9 28 4.1 23 1536

1.47

LO

-18

D36

-3C

240

960

44 170

37 10.0

41 6.7 38 8.6 25 3.5 22 1606

2.11

L 1

8-49

D36

-3D

290

1300

47 190

39 11.0

48 7.5 45 11.0

31 4.6 27 2051

2.46

L1

8^9

D37

^A35

014

00 74 290

63 18.0

68 11.0

61 12.0

33 4.8 29 2414

2.01

BO

-50

D37

^B34

013

00 73 280

59 17.0

63 11.0

56 11.0

32 4.5 28 2275

1.91

LO

-30

D37

^C29

015

00 58 220

47 14.0

53 8.9 50 11.0

31 4.2 26 2313

2.65

L 3

0-50

D41

-1A

300

1500 68 260

57 16.0

61 10.0

53 11.0 29 4.2 25 2394

2.45

BO

-72

D41

-1B

350

1400 78 290

64 18.0

69 11.0

60 12.0

33 4.5 28 2418

1.97

LO

-32

D41

-1C

260

1600 57 220

49 13.0

48 8.3 45 9.1 26 3.7 22 2361

3.05

L 3

2-73

D42

-1A

330

920

68 270

59 17.0

64 11.0

58 12.0

33 4.6

28 1875

1.41

BO

-20

D42

-1B

330

950

66 260

56 16.0

59 9.9 53 11.0

29 3.9 25 1869

1.47

LO

-7

D42

-1C

390

1100 78 310

64 19.0

72 12.0

64 14.0

39 5.2 33 2200

1.44

L7-

20

Ana

lysi

s by

Ind

uctiv

ely

Cou

pled

Pla

sma-

Mas

s Sp

ectr

omet

ry (

ICP-

MS)

; an

alys

ts:

G. O

. Rid

dle

and

M. J

. Mal

colm

Inte

rval

s ar

e m

easu

red

from

the

oute

r sur

face

of t

he c

rust

; B

=bul

k, th

e en

tire

crus

t thi

ckne

ss w

as s

ampl

ed a

nd a

naly

zed;

L=l

ayer

Ce*

= 2

Ce/

La+

Pr fr

om c

hond

rite

-nor

mal

ized

dat

a

Tab

le 1

2. C

orre

latio

n co

effic

ient

mat

rix fo

r 46

bulk

cru

sts

liste

d in

Tab

le 6

; n=4

6, e

xcep

t for

Pt,

Rh,

Ru,

and

Ir =

19; t

he z

ero

corr

elat

ions

for 4

6 po

ints

and

19

poin

ts a

t the

99%

con

fiden

ce le

vel a

re 1

0.374

1 an

d 10

.5681

, res

pect

ivel

y

to

LaL Lon

g.Fe M

nFe

/Mn

Si Ni

At K Mg

Ca

Ti P H20

+m

o-cm L

OI

N Cu

Zn

Co Ba Mo

Sr Ce

Y V Pb Cr

Cd

As Pt Rh

Ru

Ir Thi

ck

Zn

Co Ba

Mo

Sr Ce Y V Pb Cr

Cd

As Pt Rh

Ru

Ir Thi

ck

Dep

th-0

.014

-0.4

10-0

.048

-0.1

060.

025

0.08

7-0

.179

0.14

39.

097

-0.1

80-0

329

0.45

3-0

333

-032

10.

258

-038

90.

248

-0.1

35-0

.125

-0.1

69-0

.037

0.13

9-0

.075

0.17

503

36-0

.094

0.01

60.

174

-0.0

180.

142

-0.0

69-0

.042

0.09

00.

136

0.04

2-0

.040

Cu 0.63

003

020.

185

0.06

3-0

.095

0.01

9-0

353

0.26

4-0

.496

-0.2

620.

158

-036

30.

199

0.12

203

620.

090

0.23

9

LaL -0.7

48-0

.221

-0.2

610.

132

0.23

50.

076

0310

0341

0.13

1-0

.034

-0.1

01-0

.012

-0.4

78-0

.159

0.01

2-0

.247

-0.1

30-0

324

-0.4

19-0

.424

-0.0

960.

011

-0.1

0603

2103

93-0

.345

0362

0313

-0.1

470.

064

0.10

60.

153

-0.3

030.

148

0.11

6

Zn 0.02

20.

507

0.47

40.

385

0.16

3-0

.088

0.73

10.

010

-0.6

27-0

.120

-0.0

640.

111

-0.0

55-0

.114

-0.1

12-0

.050

Lon

g.

0.43

50.

447

-0.0

85-0

.179

0.10

4-0

302

-0.2

110.

138

0.01

1-0

.082

-0.0

380.

755

0.09

2-0

.030

0.18

30.

181

0.33

10.

571

0.42

10.

038

0.15

60.

196

-0.4

38-0

339

0375

-0.2

87-0

.203

-0.0

220.

257

-0.1

48-0

323

0.18

0-0

306

-0.2

73

Co

-0.6

01-0

.156

-0.5

22-0

.639

-0.5

47-0

347

-0.5

910.

011

0.74

20.

166

-0.0

660.

018

0.82

2-0

.013

-0.1

02

Fe -0.1

029.

685

0.42

30.

509

0318

0.16

60.

114

-0.4

810.

133

-0.5

0403

79-0

.126

-0.4

94-0

.089

-0.5

820.

060

0.26

6-0

.115

0.07

2-0

.191

-0.0

84-0

.171

-0.4

720.

481

-0.0

700.

228

-0.6

490.

644

-0.6

31-0

.716

-0.1

10-0

.710

-0.6

56

Ba 0.67

00.

797

0.84

00.

561

0.75

60.

597

-0.5

09-0

381

-030

90.

430

0.24

7-0

.609

0.26

10.

233

Mn

-0.7

47-0

.714

-0.4

36-0

.725

-0.2

000.

042

-0.0

0703

78-0

.099

0.71

50.

573

-0.0

500.

703

0.66

60.

467

0.58

50.

421

0315

0.76

303

650.

181

0.13

90.

406

0.00

3-0

.436

0.42

2-0

.005

0354

0.20

60.

091

0.16

00.

132

Mo

0.77

40.

578

0.61

40.

574

0.50

0-0

.483

0.07

2-0

.068

0.45

30.

262

-0.4

830.

274

0.24

1

Fe/M

n

0.74

70.

630

0.69

30.

201

0.00

4 0

.274

-0.1

86-0

.224

-0.2

91-0

.537

-0.2

49-0

.585

-0.8

33-0

.251

-0.1

49-0

.456

-0.1

06-0

.584

-0.2

48-0

.171

-035

90.

061

-0.0

0903

70-0

.739

0374

-0.6

35-0

.638

-0.2

49-9

.594

-0.4

68

Sr 0.58

50.

738

0.64

10.

577

-0.4

71-0

.250

-0.2

0903

060.

110

-0.6

930.

126

0.14

1

Si 0.70

70.

945

0.63

10.

483

-0.5

84-0

302

-0.5

14-0

.441

-035

8-0

.529

-0.4

24-0

.437

-0.2

69-0

.415

0.04

0-0

.634

-0.8

36-0

.711

-0.5

37-0

.576

-0.4

24-0

.202

0.58

7-0

.216

0.50

0-0

.613

-0.4

6403

11-0

.475

-0.5

52

Ce 0.69

50.

462

0.67

7-0

.409

-0.2

51-0

395

0.52

60.

470

-0.5

750.

445

0385

Ma 0.58

30.

257

0357

-035

9-0

.434

-033

4-0

.091

-0.4

36-0

.341

-039

9-0

.424

-0.1

290.

020

-0.1

09-0

.340

-0.4

80-0

.323

-0.4

73-0

.467

-0.0

55-0

.055

0365

-0.4

330.

546

-0.5

11-0

.548

0.07

8-0

.507

-0.6

00

Y 0.15

20.

717

-0.2

76-0

.064

-034

30.

509

0.45

5-0

.601

0.44

20.

300

Al 0.75

20.

506

-0.5

57-0

.139

-0.4

91-0

356

-0.2

69-0

.538

-036

4-0

380

-0.1

15-0

.452

0.02

8-0

.614

-0.8

77-0

.788

-0.4

49-0

.562

-0.5

11-0

310

0.64

0-0

.200

0.27

9-0

.520

-037

003

36-0

374

-037

0

V 0329

-0.4

44-0

.429

0.11

2-0

.061

-0.1

77-0

.449

-0.2

11-0

.194

K 0.78

8-0

.717

0.11

8-0

.694

-0.2

570.

295

-0.7

250.

203

0.15

50.

194

-037

80.

423

-0.6

65-0

.577

-0.8

49-0

.422

-0.5

92-0

.532

-0.4

870.

632

0.16

10.

277

-0.2

90-0

.153

0.58

0-0

.156

-0.1

50

Pb -0.2

47-0

.269

0.11

603

7003

16-0

.542

0316

-0.0

63

Mg

-0.5

72-0

.186

-0.5

730.

054

0.26

5-0

.569

0.24

90.

421

0.14

6-0

.190

0.65

1-0

.774

-039

2-0

.763

-0.7

12-0

.635

-0.5

57-0

.559

0.53

50.

298

0.45

2-0

.263

-0.2

290.

606

-0.1

96-0

.205

Cr

-0.1

690.

400

-0.4

30-0

375

0.15

0-0

306

-0.2

81

Ca

-0.2

880.

993

0.03

0-0

383

0.97

8-0

.404

-0.0

44-0

.228

-0.0

46-0

.428

0.39

60.

374

0.70

10.

298

0.71

90.

017

0.26

6-0

.255

-0.1

09-0

.557

9.42

00.

265

-0.5

5003

330.

472

Cd

-0.1

990.

287

0.43

40.

636

0.35

50.

214

TI -034

40.

128

0.46

2-0

374

0.50

30.

074

0.58

503

150.

027

0.43

30.

163

-0.0

040.

521

-0.0

5503

36-0

.092

-0.2

870.

062

-032

60.

196

0.22

40.

104

0.11

30.

198

As -0.5

70-0

.567

0.08

9-0

.549

-0.7

69

P -0.0

53-0

.428

0.98

5-0

.461

-0.0

75-0

.273

-0.1

07-0

.441

0341

0.29

50.

651

0.26

40.

702

-0.0

380.

259

-0.2

27-0

.106

-0.5

650.

401

0.27

4-0

.535

0341

0.47

4

Pt 0.90

4-0

.057

0.93

30.

756

H2O

+

0.32

3-0

.019

0.42

20.

237

0.22

90.

466

0.30

20.

286

0.54

303

90-0

.054

-0.0

600.

463

0.00

2-0

.224

9.01

20.

316

0.08

7-0

.174

-0.0

69-0

.125

-0.1

15

Rh 0.13

39.

961

0.69

3

H2O

-

-0.4

530.

970

0.60

60.

445

0.15

40.

515

0.08

703

05-0

.196

0.15

9-0

.192

0.07

4-0

.112

-0.1

430.

415

-0.0

270.

428

0.43

50.

434

0.48

003

33

Ru 0.08

1-0

.165

CO

2

-0.4

69-0

.054

-032

4-0

.097

-0.4

2003

2003

520.

683

0.25

10.

736

-0.0

050.

285

-0.2

61-0

.073

-0.4

8903

560.

248

-0.5

620.

296

0.41

7

Ir 0.75

6

LO

I

0.65

80.

517

0.32

10.

553

0.12

60.

392

-0.1

350.

142

-0.2

280.

188

-0.1

40-0

.257

0.45

0-0

.001

0388

0.37

10.

418

0388

0.27

5

N 0.42

30.

181

0.73

0-0

.260

0303

-0.1

54-0

.216

-0.0

86-0

.273

-035

5-0

.250

0.82

9-0

.224

0.44

50.

451

0.51

10.

433

0.41

9

Tab

le 1

3. C

orre

latio

n co

effi

cien

t mat

rix

for 9

bul

k cr

usts

>70

mm

list

ed in

tabl

e 6;

n=9

, exc

ept f

or P

t, R

h, R

u, a

nd Ir

= 5

; the

zer

o co

rrel

atio

ns f

or 9

poi

nts

and

5 po

ints

at t

he 9

5% c

onfi

denc

e le

vel a

re 1

0.665

1 an

d 10

.883

1, re

spec

tivel

y

U)

LaL

Lon

g.Fe M

nFe

/Mn

Si Na

Al K Mg

Ca

Ti P H20

+H

2O-

CO

2L

OI

N Cu

Zn

Co

Ba

Mo

Sr

Ce

Y V Pb Cr

Cd

As Pt Rh

Ru

Ir Thi

ck

Zn

Co Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As Pt Rh

Ru

Ir Thi

ck

Dep

th0.

534

-0.5

910.

546

-032

20.

837

0.71

70.

036

0.97

00.

869

0.46

7-0

.636

0.83

4-0

.647

-0.5

120.

598

-0.7

280.

510

-0.8

950.

707

-0.2

99-0

.780

0359

-0.5

04-0

.794

0.69

8-0

.638

0.26

0-0

.410

0.83

0-0

.703

0.02

4-0

.716

-0.7

670.

174

-0.8

38-0

.493

Cu 0.28

1-0

.182

0.85

4-0

.805

-0.6

8903

11-0

.964

0.08

5-0

.480

0.61

7.0

.970

0.10

5 0

.146

-0.5

200.

769

-0.4

93-0

.094

Lat

.

-0.8

770.

251

0.20

80.

281

0.58

80.

138

0.55

00.

712

0.50

2-0

.802

0.49

3-0

.775

-0.4

220.

685

-0.6

860.

668

-0.1

26-0

.002

-0.1

12-0

.500

-0.0

080.

446

-0.6

080.

919

-0.1

100.

838

0.49

50.

219

-0.0

680.

584

-0.4

61-0

.090

-031

9-0

.234

-0.8

84

Zn 0.80

80.

732

0.09

1-0

.204

0.03

7-0

.458

0.44

30.

497

-037

0.0

328

0.69

00.

798

0.62

20.

627

0.66

20.

022

Lon

g.

0.06

50.

134

-0.1

61-0

.291

0310

-0.4

91-0

.539

-0.1

640.

513

-035

20.

484

0.77

7-0

383

0.42

3-0

356

0.19

10.

112

0.52

40.

750

0331

-033

80.

505

-0.8

00-0

.124

-0.4

98-0

.173

-0.4

63-0

.026

-0.1

300.

669

0.28

70.

612

0.44

30.

645

Co 0.27

60.

255

0.33

0-0

.451

0.06

50.

016

0.44

1-0

.639

0.13

80.

309

0.97

70.

835

0.31

80.

909

0.45

2

Fe 0.41

30.

733

0.84

60.

840

0.72

50.

794

0.91

7-0

.775

0.87

6-0

.803

0.43

30.

859

-0.8

710.

833

-0.6

390.

865

0.62

60.

076

0.96

3-0

.422

-0.7

670.

513

-0.9

580.

518

0.02

303

29-0

.874

0.57

80.

100

-0.1

440.

774

-0.1

45-0

348

Ba

-0.4

98-0

.598

0.27

0-0

.939

0346

-0.0

360.

205

-0.8

440.

497

0.28

2-0

.056

0.89

1-0

.016

-0.1

36

Mn

-0.2

860.

148

0.76

4-0

.140

0.14

10.

652

-0.4

470.

210

-0.4

470.

698

0.53

8-0

372

0.63

503

53-0

.030

0.85

40.

709

0.42

90.

498

-0.2

9903

04-0

.151

0.66

30.

764

-031

9-0

.115

0.74

60.

764

0.82

60.

157

0.78

3-0

.090

Mo

0.22

30.

197

0.65

50.

509

0.87

8-0

.568

0.70

70.

448

0.25

30.

708

-0.6

390.

621

-030

2

Fe/M

n

0.86

603

270.

896

0.79

80.

513

-0.5

890.

764

-0.6

10-0

.124

0.57

3-0

.707

0.47

0-0

.871

0.85

40.

000

-0.5

120.

643

-0.6

76-0

.598

0.42

5-0

.855

0.20

2-0

.400

0.51

0-0

.748

0.18

6-0

.545

-0.7

560.

629

-0.7

43-0

.491

Sr

-0.8

690.

702

-0.6

030.

000

-0.7

160.

803

-039

00.

204

0.23

4-0

.219

0338

0.43

2

Si 0.62

00.

850

0.91

70.

792

-0.8

840.

821

-0.8

930.

061

0.85

7-0

.917

0.79

1-0

.618

0.70

20.

293

-031

00.

710

-0.2

66-0

.718

0.68

5-0

.822

0.65

50.

103

0.28

1-0

.652

0.64

1-0

339

-039

20.

561

-0.4

21-0

.761

Ce

-038

40.

820

0327

0.48

8-0

.422

0.55

0-0

357

-0.1

32-0

.123

-0.2

77-0

.738

Na 0.27

50.

466

0.85

4-0

.637

0.53

3-0

.655

0.78

90.

733

-0.6

540.

761

-0.1

270.

504

0.93

20.

542

0.87

3-0

.027

-0.4

5603

03-0

.692

0.61

60.

444

-0.1

80-0

.528

0.80

70.

528

0.36

40.

721

0.38

2-0

.266

Y -0.2

910.

248

-0.4

400.

928

-035

70.

055

0.38

1-0

.837

0.35

60.

256

Al 0.94

80.

648

-0.7

650.

922

-0.7

80-0

304

0.74

7-0

.856

0.66

7-0

.889

0.79

8-0

.068

-0.6

270.

554

-0.4

92-0

.860

0.73

8-0

.782

0.40

0-0

.285

0.73

8-0

.793

0.22

5-0

.576

-0.6

6303

50-0

.723

-0.5

56

V 0.76

3-0

.070

-0.1

700.

915

0.03

70.

300

0.02

10.

192

-0.7

89

K 0.81

5-0

.929

0.94

3-0

.937

-0.1

610.

909

-0.9

690.

854

-0.7

180.

701

0.13

4-0

.471

0.60

3-0

.242

-0.9

170.

873

-0.7

590.

666

0.02

80.

578

-0.7

300.

504

-041

9-0

.418

0322

-0.5

01-0

.699

Pb -0.6

190.

401

0.80

70.

416

0.75

6-0

.214

0.69

1-0

.463

Mg

-0.9

050.

857

-0.9

200.

388

0.97

0-0

.930

0.97

8-0

.424

0.63

90.

663

0.12

00.

823

-0.0

62-0

.845

0.72

4-0

.773

0.77

70.

340

0.26

7-0

.722

0.75

70.

181

0.11

30.

502

0.05

4-0

.473

Cr

-0.6

95-0

358

-0.4

91-0

.618

-0.0

15-0

.691

0.01

4

Ca

-0.8

410.

999

-0.0

35-0

.980

0.97

5-0

.960

0.42

6-0

.501

-035

80.

223

-0.5

89-0

.076

0.85

6-0

.909

0.64

1-0

.889

-038

9-0

305

0.56

1-0

.770

0.18

20.

081

-0.2

620.

177

0.77

9

Cd

-0.1

340.

055

0.39

1-0

.662

0.39

50.

054

TI -0.8

62-0

.012

0.88

6-0

.935

0.84

6-0

.807

0.84

10.

254

-032

00.

739

-0.4

12-0

.966

0.76

8-0

.856

0.52

2-0

.120

0.69

3-0

.901

0382

-0.2

30-0

361

0.44

0-0

.427

-042

7

As 0.26

904

200.

296

0376

-0.6

85

P -0.0

57-0

.986

0.98

4-0

.966

0.45

7-.0

540

-0.3

760.

212

-0.6

24-0

.035

0.87

0-0

.898

0.67

5-0

.872

-035

9-0

.325

0.59

9-0

.759

0.16

90.

093

-0.2

990.

185

0.75

5

Pt 0.86

10.

246

0.91

10.

509

H2O

+

0.17

4-0

.059

0.23

60.

254

0.17

70.

939

0.91

50.

617

0.00

20.

100

-030

8-0

321

0.13

903

51-0

.517

-0.1

790.

470

0.87

10.

620

0.65

60.

710

0.26

5

Rh

-0.1

750.

985

0.22

3

H2O

-

-0.9

820.

992

-0.4

610.

590

0486

-0.0

930.

707

-0.0

03-0

.893

0.85

8-0

.721

0.84

703

4903

35-0

.668

0.75

6-0

.034

-0.0

1203

65-0

.096

-0.6

43

Ru

-0.0

650.

009

C02 -0.9

510.

598

-0.6

78-0

.363

0.24

5-0

.707

0.13

80.

916

-0.8

620.

781

-0.7

73-0

.201

-0.4

390.

728

-0.6

650.

193

0.20

0-0

.397

0.27

90.

674

Ir 0.30

5

LO

I

-037

40.

529

0.54

90.

002

0.69

10.

076

-0.8

740.

844

-0.6

680.

869

0423

0.28

6-0

.628

0.78

30.

072

0.10

90.

327

0.02

0-0

.593

N -0.9

050.

142

0.56

1-0

.560

0.82

10.

694

-039

20.

794

0.03

30.

665

-0.8

390.

875

0.15

30.

503

0.78

1-0

472

0.78

80.

146

Tab

le 1

4. C

orre

latio

n co

effi

cien

t mat

rix f

or 5

bul

k cr

usts

<ll

mm

list

ed in

tabl

e 6;

the

zer

o co

rrel

atio

n fo

r 5 p

oint

s at

the

95%

con

fide

nce

leve

l is

10.88

31

Lat

Lon

g.Fe M

nFe

/Mn

Si Na

Al K Mg

Ca

Tl P H2O

+H

20-

C02

LO

IN C

uZ

nC

oB

aM

oS

r Ce

Y V Pb Cr

Cd

As Thi

ck

LO

IN C

uZ

nC

oB

aM

oSr C

eY V Pb C

rC

dAs T

hick

Dep

th-0

.854

-0.4

140.

136

-0.0

910.

124

0.35

7-0

.419

0.21

0-0

.024

0.23

7-0

.430

0.52

8-0

.149

0.28

6-0

.323

-0.5

28-0

.390

-0.0

630.

610

0.35

2-0

.324

-0.2

83-0

.338

-0.0

060.

431

-0.5

73-0

.065

0.35

0-0

.261

0.09

6-0

.067

-0.8

47

C02 0.

829

0.14

7-0

.980

-0.2

110.

357

0.77

10.

876

0.83

9-0

.988

0.80

60.

864

0.51

1-0

.601

-0.2

270.

877

0.01

0

LaL

0.36

20.

248

-0.0

880.

178

-0.1

600.

822

-0.4

09-0

.419

0.26

00.

166

-0.8

080.

413

-0.5

900.

173

0.65

80.

358

-OJ3

3-0

.670

-0.1

12-0

.060

0.14

20.

288

0.25

3-0

.638

0.41

30.

201

0.09

7-0

.078

-0.5

580.

277

0.54

2

LO

I

0.59

9-0

.899

-0.6

720.

730

0.91

00.

945

0.63

9-0

.793

0.95

30.

795

0.25

4-0

.637

0.25

60.

724

-0.0

35

Lon

g.

0.48

40.

840

0.2

72-0

.946

0.07

6-0

.888

-0.4

77-0

.407

0.86

6-0

.685

0.70

30.

396

0.85

50.

900

0.94

80.

558

-0.9

29-0

.459

0.70

40.

969

0.99

70.

760

-0.8

530.

949

0.88

8O

J18

-0.5

640.

213

0.82

9-0

.023

N -0.2

76-0

.734

0.96

00.

719

0.58

50.

049

-0.0

500.

668

0.30

7-0

.359

-0.0

670.

926

0.14

20.

070

Fe 0.15

30.

563

-0.2

180.

443

-0.7

86-0

.947

0.37

90.

000

-0.6

980.

941

-0.2

400.

094

0.68

20.

358

-0.2

97-0

.533

0.40

8-0

.230

0.37

70.

499

0.93

2-0

.768

0.20

30.

803

0.95

8-0

.760

-0.5

590.

886

-0.5

92

Cu 0.39

4-0

.492

-0.8

11-0

.901

-0.7

380.

948

-0.8

93-0

.809

-0.3

620.

552

0.09

5-0

.798

-0.1

19

Mn

-0.6

63-0

.945

-OJ1

3-0

.653

-0.1

47-0

.563

0.93

2-0

.273

0.31

30.

820

0.95

10.

542

0.88

80.

868

-0.6

29-0

.713

0.88

60.

917

0.86

60.

480

-0.4

900.

854

0.69

40.

090

-0.5

220.

628

0.56

8-0

.171

Zn

-0.7

80-0

.491

-0.4

500.

125

0.14

0-0

.675

-0.1

110.

408

0.16

0-0

.609

0.01

1-0

.281

Fe/M

n

0.52

00.

363

0.00

7-0

436

0.46

7-0

.685

-0.1

820.

453

-0.7

71-0

.721

0.05

5-0

.490

-0.7

970.

131

0.95

3-0

.762

-0.3

69-0

.280

0.29

4-0

.124

-0.4

940.

047

0.51

60.

042

-0.7

690.

190

-0.1

92

Co 0.81

30.

711

0.13

9-0

.245

0.83

00.

394

-OJ5

1-0

.075

0.81

70.

243

0.24

1

Si 0.19

10.

721

0.19

70.

624

-0.9

720.

437

-0.4

56-0

.641

-0.9

33-0

.717

-0.9

28-0

.795

0.79

30.

637

-0.8

93-0

.982

-0.9

51-0

.557

0.64

2-0

.962

-0.7

53-0

.069

0.42

0-0

.514

-0.6

45-0

.044

Ba 0.98

00.

688

-0.7

110.

926

0.85

10.

222

-0.4

970.

421

0.76

0-0

.073

Na

-OJ7

4-0

.660

0.75

7-0

.221

-0.7

720.

410

-0.7

34-0

.078

0.46

90.

141

-0.6

70-0

.424

0.11

7-0

.484

-0.1

690.

025

0.28

4-0

.539

0.03

70.

137

0.44

0-O

J49

-0.8

560.

265

0.09

5

Mo

0.77

7-0

.834

0.93

30.

907

0.34

6-0

396

0.24

50.

843

-0.0

93

Al 0.82

0-0

.032

-038

50.

850

-0.8

79-0

.151

-0.6

76-0

.933

-0.8

57-0

.208

0.89

90.

221

-034

0-0

.795

-0.8

92-0

.929

0.95

8-0

.741

-0.9

58-0

.693

0.83

50.

167

-0.9

610.

327

Sr -0.8

8303

240.

964

0.83

9-0

.792

-0.2

740.

993

-0.4

92

K -0.5

47-0

.021

0.82

6-0

.879

0.30

4-0

.176

-0.7

23-0

.438

0.35

60.

606

-0.2

360.

257

-0.3

21-0

.480

-0.8

700.

820

-0.2

47-0

.746

-0.9

380.

838

0.65

1-0

.839

0.52

3

Ce

-0.7

27-0

.880

-0.6

290.

693

0.32

7-0

.910

0.11

0

Mg

-0.6

67-O

J07

0.13

0-0

.662

-0.4

54-0

.056

-0.3

02-0

.835

0.14

70.

394

-0.8

32-0

.573

-0.4

150.

074

-0.0

80-0

.513

-0.1

330.

543

-OJ6

1-0

.847

0.00

7-0

.366

Y 0.70

30.

034

-0.3

860.

357

0.61

80.

219

Ca

-0.3

430.

254

0.68

40.

959

0.60

60.

899

0.85

6-0

.724

-0.7

870.

953

0.91

00.

864

0.35

8-0

.514

0.95

50.

587

-0.1

35-0

.294

0.61

20.

462

0.19

1

V 0.69

7-0

.783

-0.0

320.

986

-0.4

21

n -0.8

030.

318

-0.4

33-0

.922

-0.6

710.

177

0.88

80.

113

-0.0

46-0

.487

-0.6

48-0

.741

0.94

9-0

.595

-0.6

96-0

.585

0.62

30.

531

-0.7

60-0

.007

Pb -0.8

31-0

.577

0.78

4-0

.760

P -0.1

730.

285

0.86

30.

546

-0.1

13-0

.747

0.25

00.

020

0.59

40.

703

0.97

0-0

.902

0.47

00.

895

0.81

2-0

.670

-0.4

280.

953

-OJ4

5

Cr

0.22

0-0

.799

0.71

6

1120

+

0.67

8-0

.031

0.47

50.

933

-0.0

73-0

.641

0.80

50.

585

0.44

70.

041

0.08

40.

456

0.27

2-0

.208

-0.2

090.

904

0.11

4-0

.244

Cd

-0.1

980.

117

H2O

-

0.62

80.

953

0.78

3-0

.743

-0.8

370.

865

0.87

30.

859

0.41

8-0

.571

0.92

60.

631

0.02

1-0

.504

0.50

80.

520

0.02

1

As -0.4

41

Tab

le 1

5. C

orre

latio

n co

effi

cien

t mat

rix

for

5 la

yers

from

D27

-5 l

iste

d in

tabl

e 6;

the

zero

cor

rela

tion

for

5 po

ints

at

the

95%

con

fide

nce

leve

l is

10.88

31

Mn

Fe/M

nSi N

a4 K M

gC

aTl P H

2O+

mo-

cm LO

IN C

uZ

nC

oB

aM

oSr C

eY V Pb C

rC

dAs ft R

hR

uIr T

hick

Zn

Co Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As ft Rh

Ru

Ir Thi

ck

Fe -0.4

140.

916

0.74

003

300.

337

0.09

30.

029

-0.4

440.

281

-0.4

100.

909

-036

5-0

.570

-0.2

41-0

.537

-0.5

19-0

.536

0315

-0.4

39-0

.290

-020

2-0

352

-0.4

010.

242

0372

0.56

7-0

.469

0.87

0-0

.544

-0.4

380.

135

-0.4

51-0

426

Cu 0.70

402

50-0

.091

0.13

8-0

349

0.23

8-0

.449

-028

1-0

315

0255

0.66

2-0

254

0.88

40.

958

0.53

00.

973

0.44

9

Mn

-0.6

73-0

.127

0312

.277

0.54

00.

758

-0.5

65-0

.093

-0.6

04-

.283

0.99

3-0

.481

0.97

10.

945

0.91

60.

598

0.47

6-0

.351

0.01

4-0

.590

-0.0

38-0

.648

-0.4

03-0

.446

0.41

20.

859

0.00

0 .7

870.

909

0.60

50.

919

0.30

9

Zn

-0.3

920.

491

.795

0.27

30.

755

-0.0

050.

401

0.31

0-0

.291

0.23

1-0

355

0.95

40.

837

-0.1

900.

812

0.83

6

Fe/M

n

0.70

0 .0

17 .2

33-0

.078

-0.1

56-0

.197

0.04

9-0

.151

0.82

2-0

.608

-028

3-0

.492

-0.6

92-0

.811

-0.7

220.

164

-032

2-0

317

-0.0

44-0

.422

-0.1

070.

228

0.33

00.

307

-0.5

600.

736

-0.7

97-0

.743

-0.1

08-

.757

-0.7

99

Co

-0.9

84-0

.800

-0.9

88-0

.842

-0.8

58-0

.758

-0.6

850.

909

0.63

50.

586

-0.1

350.

145

0.90

90.

175

-0.6

58

Si 0.47

80.

857

0.65

60.

524

-0.7

180.

164

-0.6

830.

936

-0.0

44-0

.721

0.04

3-0

.069

-032

7-0

.789

0.79

9-0

.874

-0.8

37-0

.706

-0.8

68-0

.603

-0.4

69-0

348

0.80

50.

079

0.76

8-0

.637

-0.4

040.

607

-038

3-0

.974

Ba 0.80

90.

959

0.89

10.

836

0.69

10.

611

-0.9

05-0

.540

-0.6

8902

64-0

.008

-0.8

31-0

.034

0.74

8

Ma 0.64

20.

705

0.45

4-0

.594

0.83

1-0

.604

0.54

10.

288

-0.6

800.

284

0.19

10.

441

-0.1

310.

575

-0.5

02-0

.489

-0.5

16-0

.219

-0.6

11-0

351

-0.2

280.

751

0.11

70.

275

0.10

90.

309

0.80

70.

344

-0.4

85

Mo

0.72

90.

907

0.40

80.

832

0.74

4-0

.633

-031

6-0

314

0.57

90.

347

-0.7

170.

301

0.77

8

Al 0.94

60.

798

-0.8

030.

210

-0.7

870.

681

0.34

1-0

.745

0.37

00.

380

0.11

8-0

.584

0.95

5-0

.942

-0.9

33-0

.909

-0.8

80-0

.706

-0.8

16-0

.724

0.85

20.

488

0.48

2-0

323

-0.0

480.

897

-0.0

07-0

.757

Sr 0.79

90.

872

0.76

90.

717

-0.8

72-0

.741

-0.5

320.

015

-0.2

56-0

.902

-028

40.

540

K 0.88

6-0

.806

0244

-0.8

080.

459

0.58

1-0

.734

0.58

00.

619

0.42

7-0

316

0.93

8-0

.871

-0.8

19-0

.930

-0.7

31-0

.749

-0.8

65-0

.797

0.82

40.

672

0307

-0.0

2102

500.

979

0.29

4-0

.524

Ce 0.50

10.

759

0.70

0-0

.639

-042

4-0

.517

0.58

703

62-0

.607

0332

0.76

3

Mg

-0.8

97-0

.114

-0.9

050.

294

0.81

5-0

.791

0.84

50.

806

0.52

3-0

.051

0.92

6-0

.870

-0.5

75-0

.972

-0.6

67-0

.873

-0.7

37-0

.714

0.79

80.

858

0.42

70.

203

0.45

10.

874

0.47

5-0

333

Y 0383

0313

-0.9

38-0

.555

-0.7

18-0

.221

-0.4

64-0

.815

-0.4

720.

474

Ca

-0.0

780.

999

-0.6

15-0

.626

0.97

7-0

.704

-0.5

13-0

337

0.15

8-0

.926

0.91

80.

547

0.92

60.

644

0.98

40.

482

0.40

6-0

.963

-0.5

57-0

.749

-0.0

65-0

325

-0.8

42-0

338

0.58

7

V 0.98

7-0

.461

-0.7

300.

042

0.15

2-0

.053

-0.7

57-0

.103

0.32

4

Ti -0.0

8703

65-0

.161

-0.2

32-0

.195

-0.2

500.

210

-0.0

850.

053

0.00

6-0

.183

0.03

60.

190

-0.1

140.

038

0.15

403

11-0

371

-0.0

240.

030

0.09

503

630.

121

-0.2

86

Pb -035

1-0

.787

0.13

80.

081

-0.0

99-0

.679

-0.1

460.

188

P -0.5

80-0

.661

0.97

5-0

.735

-0.5

45-0

.385

0.11

1-0

.918

0.90

20.

521

0.92

40.

613

0.99

10.

479

0.40

6-0

.957

-0.5

79-0

.724

-0.1

16-0

.374

-0.8

49-0

.387

0.54

9

Cr

0.38

10.

752

-0.0

590.

209

0.87

10.

229

-0.7

21

H2O

+

-022

4-0

.693

-0.1

24-0

321

-0.4

00-0

.723

0.60

9-0

.700

-0.6

53-0

.491

-0.6

40-0

.531

-0.1

69-0

.024

0.75

6-0

220

0.81

8-0

.622

-0.4

310.

462

-0.4

20-0

.978

Cd

-0.0

200.

433

0.58

60.

629

0.60

80.

142

H2O

-

-0.5

300.

989

0.95

60.

865

0.52

80.

547

-0.4

34-0

.051

-0.6

59-0

.136

-0.6

94-0

.449

-0.4

900.

462

0.89

50.

076

0.72

20.

861

0.63

10.

870

0239

As -030

6-0

.142

0340

-0.1

58-0

.744

CO

2

-0.6

16-0

.372

-0.3

030.

145

-0.8

550.

855

0.47

90.

836

0.54

00.

977

0.33

40.

237

-0.9

80-0

.390

-0.8

02-0

.061

-0.3

10-0

.802

-032

00.

630

Pt 0.96

00.

109

0.94

80.

721

LO

I

0.91

80.

803

0.48

80.

596

-0.5

02-0

.061

-0.7

01-0

.189

-0.7

70-0

.407

-0.4

380.

536

0.87

00.

216

0.67

40.

825

0.63

40.

830

0.15

3

Rh 0.37

70.

998

0.52

0

N 0.81

60.

419

0.54

1-0

.419

-0.1

68-0

.656

-0.2

31-0

.549

-0.6

26-0

.686

0344

0.97

3-0

.105

0.62

00.

753

0.61

80.

772

0277

Ru

Ir

0.41

7-0

.488

0.

502

Tab

le 1

6. C

orre

latio

n co

effic

ient

mat

rix fo

r 5 la

yers

from

D32

-9 li

sted

in ta

ble

6; th

e ze

ro c

orre

latio

n fo

r 5 p

oint

s at

the

95%

con

fiden

ce le

vel i

s 10

.8831

ON

Mn

Fe/M

nSi N

aAl K M

gC

aTi P H

2O+

H2O

-C

O2

LO

IN C

uZ

nC

oB

aM

oS

rC

eY V Pb C

rC

dA

s Pt Rh

Ru

Ir Thi

ck

Zn

Co

Ba

Mo

Sr Ce

Y V Pb Cr

Cd

As Pt Rh

Ru

Ir Thi

ck

Fe -0.6

210.

986

0.45

4-0

.093

-0.1

23-0

.527

-0.8

02-0

.103

-0.9

040.

181

0.01

2-0

.731

0.65

4-0

.906

-0.8

92-0

.803

-0.7

29-0

.442

-0.1

800.

168

0.45

6-0

377

0.29

20.

777

0.75

80.

035

-0.8

430.

727

-0.1

59-0

.166

-035

0-0

.201

-0.2

72

Cu 0.96

50.

076

0.63

5-0

.703

-0.8

960.

773

0.16

3-0

.996

-0.9

5503

890.

509

-0.9

420.

600

0.61

60.

839

0.64

30.

262

Mn

-0.7

39-0

.967

0.83

3-0

.681

-031

70.

492

-036

80.

890

-0.5

980.

743

0.03

6-0

.056

0379

0.67

10.

032

-0.0

600.

597

-0.5

000.

626

0.40

8-0

355

-0.6

630.

000

0.00

0-0

.609

0.71

70.

000

-0.4

87-0

.497

-0.5

15-0

.475

0.05

6

Zn 0.21

60.

519

-0.6

65-0

.885

0.65

60.

040

-0.9

42-0

.997

0.59

90.

550

-0.8

290.

473

0.49

50.

851

0.52

20.

486

Fe/M

n

0.58

0-0

.246

0.04

6-0

377

-0.8

180.

027

-0.9

5503

15-0

.157

-0.6

140.

602

-0.8

39-0

.924

-0.6

93-0

.622

-0.5

41-0

.023

0.00

003

02-0

.225

0.42

20.

661

0.66

30.

124

-0.8

940.

605

-0.0

05-0

.010

-0.1

90-0

.046

-0.2

90

Co

-0.7

190.

567

0.25

6-0

.574

-0.9

660.

013

-0.2

910.

203

0.85

50.

215

-0.7

51-0

.737

0.2

87-0

.713

0.81

9

Si -0.9

260.

748

0.44

0 0

.253

0.28

9-0

.791

0.49

0-0

.780

0.05

9-0

.200

-0.2

68-0

.461

0.14

80.

276

-0.4

210.

494

-0.6

80-0

.543

0391

0.54

1-0

.162

-0.2

250.

786

-0.5

14-0

.107

0.46

70.

485

0.64

50.

469

0.16

9

Ba

-0.9

50-0

.841

0.97

80.

866

-0.6

98-0

.452

0.18

1-0

327

-0.8

050.

998

1.00

00.

834

1.00

0-0

.410

Na

-0.9

18-0

.739

0.00

0-0

.442

0.50

9-0

.544

0.91

3-0

.411

0.45

0-0

.108

0.18

3-0

.509

-0.6

0203

58-0

.687

0.86

90.

816

-0.6

48-0

.553

0.52

20.

552

0.8

190.

269

0.45

9-0

.651

-0.6

72-0

.883

-0.6

69-0

.224

Mo

0.93

6-0

.939

-0.7

610.

746

0.60

4-0

.477

0.24

30.

779

-0.9

31-0

.942

-0.9

52-0

.944

0.12

9

Al 0.90

8-0

.030

0.73

4-0

.276

0.75

1-0

.992

0.70

2-0

372

0.41

8-0

.132

0.68

30.

674

-0.5

250.

912

-0.9

94-0

.935

0.89

60.

725

-0.7

20-0

.615

0.56

8-0

.244

-0.7

310.

888

0.90

20.

962

0.90

3-0

.045

Sr -0.8

99-0

.496

0.91

30.

845

0.5

66-0

.110

0.88

4-0

.808

-0.8

25-0

.992

-0.8

39-0

.137

K 0.29

90.

687

0.15

00.

581

-0.8

550.

916

-0.5

780.

747

0.25

40.

921

0.87

6-0

.279

0.86

6-0

.924

-0.9

910.

934

0.51

1-0

.944

-0.8

370.

452

0.13

7-0

.938

0.83

80.

852

0.96

70.

868

0.05

3

Ce 0.74

9-0

.826

-0.6

000.

192

-0.1

26-0

.910

0.97

10.

974

0.87

30.

982

-030

4

Mg

-0.4

080.

673

-0.5

960.

157

0337

-0.8

930.

519

0.96

90.

622

0.71

10.

827

-0.2

080.

051

-0.3

02-0

.015

-0.6

67 0

.550

-0.7

6403

720.

960

-036

3-0

.252

-0.2

320.

245

-0.1

980.

787

Y -0.2

470.

038

-0.0

14-0

.748

-0.4

170.

886

0.87

80.

525

0.86

0-0

.688

Ca

-0.0

700.

955

-0.7

690.

721

0.19

20.

514

-034

40.

446

0.26

6-0

.841

0.94

5-0

.798

-0.6

310.

901

0.91

6-0

.527

-0.1

98-0

.139

-0.4

45-0

.703

0.96

20.

953

0.61

00.

949

-0.6

81

V 0.92

6-0

347

-0.4

410.

968

-0.6

68-0

.681

-0.8

56-0

.707

-0.1

76

Ti 036

103

670.

472

-035

40.

750

0.83

40.

479

0.36

70.

507

-0.1

150.

212

-0.0

520.

070

-0.4

62-0

.455

-0.4

12-0

.401

0.82

6-0

.446

-0.1

17-0

.120

-0.0

70-0

.089

0.10

7

Pb -0.5

91-0

.612

0.80

1-0

.405

-0.4

28-0

.808

-0.4

56-0

.534

P -0.8

130.

523

0307

0.25

0-0

.579

0.25

70.

118

-0.9

440.

909

-0.7

94-0

.555

0.81

10.

993

-0.3

41-0

.041

-0.0

34-0

.670

-0.5

120.

927

0.91

90.

571

0.90

5-0

.686

Cr

0.10

2-0

.157

0.12

70.

157

0.64

00.

161

0.72

8

H2O

+

-0.6

420.

258

-033

70.

256

-0.5

91-0

.575

0.62

0-0

.922

0.98

70.

884

-0.8

81-0

.798

0.63

60.

510

-0.5

2403

650.

668

-0.9

04-0

.915

-0.9

19-0

.912

0.13

6

Cd

-0.2

91-0

359

-034

60.

030

-031

20.

648

I12O

-

-0.4

570.

937

0.39

10.

923

0.79

5-0

.235

0.80

3-0

.757

-0.8

550.

907

0.42

6-0

.952

-0.7

670.

092

0.28

1-0

.998

0.78

90.

794

0.78

40.

815

-0.1

29

As

-0.7

88-0

.794

-0.8

18-0

.816

0.07

7

CO

2

-0.4

83-0

.777

-076

4-0

.893

-0.5

92-0

.100

0328

0.62

0-0

.252

0363

0.70

40.

919

-0.7

15-0

.733

0.50

3-0

.044

-0.0

71-0

.602

-0.1

00-0

.823

Pt 1.00

00.

800

0.99

8-0

.464

LO

I

0.62

40.

882

0.74

20.

024

0.55

7-0

.485

-0.6

620.

708

0.13

7-0

.895

-0.7

39-0

.089

0.53

8-0

.926

0.54

60.

549

0.56

10.

577

-0.0

55

Rh 0.81

80.

999

-0.4

36

N 0.60

90.

639

0.79

6-0

.211

0.12

7-0

.224

-0.0

07-0

.665

-0.5

46-0

.695

0.13

80.

993

-0.4

02-0

.245

-0.2

310.

142

-0.1

960.

626

Ru

Ir

0.82

90.

161

-0.4

18

146'

148'

150'

152'

154'

156'

158'

160'

162'

164°

166°

24'

22

'

20

'

18'

16'

14°

12'

10'

24

'

22'

20

'

18e

16e

14'

12'

10'

146°

14

8°15

0°15

2°15

4'15

6'15

8'16

0°

162'

164

166°

Figu

re 1

. B

athy

met

ry, s

eam

ount

and

guy

ot n

ames

, and

dre

dge

loca

tions

for

Tun

es 6

cru

ise;

das

hed

EEZ

boun

darie

s: w

est =

C

omm

onw

ealth

of t

he N

orth

ern

Mar

iana

Isla

nds;

sou

thw

est =

Fed

erat

ed S

tate

s of

Mic

rone

sia;

sou

thea

st =

Rep

ublic

of t

he

Mar

shal

l Isl

ands

; and

eas

t = W

ake

Isla

nd; c

onto

ur in

terv

al =

500

m

10Ir

10

Figure 2. Mean PGE concentrations in 46 bulk crusts (A) normalized to chondrites (Anders and Grevesse, 1989) and (B) to surface seawater abundance (Goldberg, 1987; Bertine et al., 1993); Pd contents of the Fe-Mn crusts are less than the limit of detection, therefore the Pd points are maximum ratios

48

10

10r Ru Rh Pt

I Pd

Figure 3. Mean PGE concentrations in D32-9H, 50-60 mm (A) normalized to chondrites (Anders and Grevesse, 1989) and (B) to surface seawater abundance (Goldberg,1987; Bertine et al., 1993); Pd contents of the Fe-Mn crusts are less than the limit of detection, therefore the Pd points are maximum ratios.

49

10000

1000-CD

c oO 100-_ CLE03

CO10-

A.

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

CLE03

CO

10-

B.

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 4. REE range plots for all 52 Fe-Mn crust samples: (A) Chondrite normalized, and (B) PAAS normalized

50

1000-q

0)

c oJZO

Q.

03 CO

100-

A

D10-1A

D12-3AD13-3A

D14-19A

D22-1AD33-2A

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q_

03 CO

10-

BLa Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 5. REE plots of bulk crusts from Wodejebato, Neen-Kiaakk, Batiza, Missy, and Aean-Kan Guyots: (A) Chondrite normalized, and (B) PAAS normalized

51

1000

d> e 100 Dc o

O

Q.

I 10 C/D

A.

D15-4A

D15-4B

D15-4C

D15-4D

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

C/D

Q.

CO OD

10-

B.

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 6. REE plots of crust samples from D15-4, Aean-Kan Guyot: (A) chondrite normalized, and (B) PAAS normalized

52

10000

1000-CD

c oO 100_CD QL

CO CO

10

A

D18-1A

D18-1B

D18-1C

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO< < QLo>QLECO

CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 7. REE plots of crust samples from D18-1, South Wake Guyot: (A) Chondrite normalized, and (B) PAAS normalized

53

10000-q

100CHCD

Cop 100-

GL

CO CO

10-

A

D23-1A

D23-1 B,C

D23-1D

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

CL

CO CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 8. REE plots of crust samples from D23-1, Maloney Guyot: (A) Chondrite normalized, and (B) PA AS normalized

54

1000CH

1000-0)

c o

O 100-

Q.

OJCO

10-

A

D23-5A

D25-3A

D25-3C

D25-3D

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

o_ oQ.

OJCO

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 9. REE plots of crust samples from D25-3, West Batiza Guyot: (A) Chondrite normalized, and (B) PA AS normalized

55

10000^

1000^CD

c oO 100

QL

CO CO

10^

A.

D27-1A

D27-1B

D27-1C

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

QL

CO CO

10-

B.

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 10. REE plots of crust samples from D27-1, Vlinder Guyot: (A) chondrite normalized, and (B) PAAS normalized

56

10000-,

1000-CD

O

0 100-_ Q.

CO CO

10-=

A

D27-5A D27-5BD27-5C D27-5D D27-5E D27-5F

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q_o 10Q.ECO

CO

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 11. REE plots of crust samples from D27-5, Vlinder Guyot: (A) Chondrite normalized, and (B) PA AS normalized

57

10000-r

100CHQ*

oO 100

CL

COCO

10-J

A

D32-8B

D32-8C

D32-8D

D32-8E

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q.

OJ CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 12. REE plots of crust samples from D32-8, Oma Vlinder Guyot: (A) Chondrite normalized, and (B) PAAS normalized

58

10000

1000-o>

o0 100-

CLE05

CO10-

A -B--o-

D32-9C D32-9D D32-9E D32-9F D32-9G D32-9H

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

CL

05 CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 13. REE plots of crust samples from D32-9, Oma Vlinder Guyot: (A) Chondrite normalized, and (B) PA AS normalized

59

10000^

1000-0)

O

o

O 100-J"o.

03 CO

10-

A

D36-3A

D36-3B

D36-3C

D36-3D

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q.

CO CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 14. REE plots of crust samples from D36-3, Golden Dragon Seamount: (A) Chondrite normalized, and (B) PAAS normalized

60

10000^

1000-CD

c oO 100^

Q.

CO CO 10-,

A

D37-4A

D37-4B

D37-4C

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO< < CL1Q.

CO CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 15. REE plots of crust samples from D37-4, Golden Dragon Seamount: (A) Chondrite normalized, and (B) PAAS normalized

61

10000^

1000-1CD

c o

_ Q.

CO CO

100r

10.

A

D41-1A

D41-1B

D41-1C

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q.

CO CO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 16. REE plots of crust samples from D41-1, Seth Guyot: (A) Chondrite normalized, and (B) PAAS normalized

62

CD c 100T3c. o

O

CO10^

A

D42-1A

D42-1B

D42-1C

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

100

CO

Q_

COCO

10-

B

La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb

Figure 17. REE plots of crust samples from D42-1, Seth Guyot: (A) Chondrite normalized, and (B) PAAS normalized

63

Factor 1: Aluminosilicate 50.2% of sample variance

o t*

0.7-

0.6-

0.5

0.4 g

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Factor 2: Residual Biogenic or other PGE-bearing phase 41.7% of sample variance

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Factor 3: CFA5.1% of sample variance

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Figure 18. Three of five Q-mode factors for 46 bulk crusts (see figure 19 for other two). Factor scores between 0 and I0.20I are not included because random noise makes it difficult to resolve the orientation of the factor to within 10° of an absolute direction in variable space.

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