fROM THEARIZONA BUREAU

Of MINES

Vol. 5, No.4 Earth Science and Mineral Resources in Arizona December, 1975

Figure 1. 20,000 square miles of Arizona and adjoining states are shown on this LAN D­SAT imagery.

by H. Wesley PeirceGeologist

Coal is Arizona's most abundantnaturally occurring fuel energy resource.This fact alone seems sufficient justifica­tion for considering seriously its possibleplace in Arizona's critical energy situa­tion. This brief article attempts toencourage and assist state and arealeaders in developing a realistic Arizonacoal perspective that, hopefully, willlead to a deliberate, responsible courseof action designed to assess fully thefuture viability of Arizona coal resources.

The sum of geologic experience inArizona indicates that the principal coalresources are on, around, and beneathBlack Mesa, a 3,200-square mile geologicremnant located exclusively on Indianlands in parts of Coconino, Navajo, andApache counties, in the plateau countryof northeastern Arizona. Although thereare other occurrences of coal andcarbonaceous materials in Arizona, theydo not appear to contain resources ofeconomic potential beyond possiblelocal usage.

Black Mesa Indian lands containingcoal resources are of three basic cate­gories: (1) Hopi land, (2) Navajo land,and (3) Joint Use land that is currentlythe subject of complex litigation. Thepresent coal operations of the PeabodyCoal Company embrace lands of thelatter two categories. Figure 1 shows thedetails of the Peabody Coal Companyproject on Black Mesa. Coal for the FourCorners power plant in New Mexico issupplied from coal resources on Navajolands in New Mexico, and additionalcoal leases on New Mexico Navajo landshave been let. There is no known currentcoal activity on Arizona Indian landsother than the Peabody operation.

Black Mesa has achieved a type offame by having its name appear onbumper stickers. However, how muchgenerally is known about it is anothermatter. By way 'of review, it is a ratherdistinctive physiographic feature, especi­ally towards the northeast where it isbounded by an escarpment with a relief

Producing oil fields1. Aneth2. Teec·Nos·Pos3. East Boundary Butte4. North Toh Alin5. Black Rock6. Dineh·bl-Keyah7. Toclte

\10 20 30 40I I I I

Miles

Inactive uraniummining areas

Coal slurry pipeline

ost Importo Energy Resource?~~~-------,

EXPLANATION

o

Activecoal-stripping

operations

NAVAJO IndianReservation

D

HOPI IndianReservation

NAVAJO-HOPIJoint-Use area

WepoCoal5.200.58

12,382

December, 1975

Table 2 - Quality and Heat Contentof Black Mesa Coals

Dakota Coal Toreva Coal11.9 13.81.62 1.09

11,125 12,338

Table 1 - Estimated Gross Coal Resourcesof Black Mesa

Billions ofshort tons Utilization

5.65 presently being mined6.00 small mines-inoperative9.60 small mines-inoperative

Av. ash (%)Av. sulphurAv. BTU/lb

Indications are that the coal resources of Black Mesa are largeand for the most part remain unexplored. The region is large andmuch of it is relatively uninhabited. There is a wide range ofopportunity, within which discussion, exploration, and possibledevelopment might be undertaken, especially as regards miningstyle (surface or underground), location and size of operations,and transportation modes. Perhaps one or more of the variousTribal jurisdictions will find it in their best interest to learn moreabout this resource and thus encourage systematic anddeliberate investigations that might be of assistance inestablishing a possible format for the planning and managementof some additional development of Black Mesa coal resources.

It seems likely that Arizona's large industries eventually willturn to coal as an energy fuel. As of this date, coal is shipped intoArizona from New Mexico and used to generate electrical power.However, can we rely upon New Mexico's continuing to ship itsdiminishing energy resources to an expanding list of Arizona'susers?

It would appear to behoove Arizona's leaders to investigateseriously all possible avenues to the development, howeverlimited, of additional Black Mesa coal resources for utilizationwithin the state. However, it should be pointed out that at the

with time), and underlie about 14,000 acres of leased Tribal land(which is about 0.7 percent of Black Mesa's total area). It isestimated that about 16 million tons of strippable coal underlieeach square mile of the Peabody lease. If one assumes that onesquare mile coal one foot thick weighs close to one million tons,one can calculate that an average of 16 feet of minable coalunderlies each square mile of the Peabody lease. Several seamshave been identified that range from 5 to 28 feet thick; none areof consistent thickness, though.

It has been stated that the coal resources of Arizona representthe greatest known concentration of conventional fuel energymaterials within the state. This is easily demonstrated by usingenergy equivalents to compare Arizona's coal reserves andpetroleum production. Conservatively, one ton of coal is theenergy equivalent of four barrels of oil. The total all-timeproduction of crude oil in Arizona is about 15 million barrels. Interms of coal equivalent this equates to less than four milliontons of coal - an amount found beneath just 1f4 -square mile ofthe Peabody lease!

The coal being mined by Peabody comes from the WepoFormation. There is no current exploitation of the othercoal-bearing formations, the Dakota and Toreva. Table 1summarizes the estimated coal resources of Black Mesa byformation. Recall that all coal occurs within 1,700 feet of thesurface.

Although the coals from these three formations arebituminous, they differ in quality as regards ash and sulphur.Both the Dakota and Toreva coals are higher in ash and sulphurcontent than the Wepo formations, as summarized in Table 2.

Wepo FormationToreva FormationDakota Sandstone

ARIZONA BUREAU OF MINESPage 2

of about 1,500 feet between the elevations 6,000-7,500 feet. Themesa surface slopes to the southwest where the less imposingsouthwest edge is at the elevation range 5,500-6,000 feet, thegeneral locale of the famous Hopi mesas. Black Mesa constitutesabout 3 percent of the land area of Arizona and is larger than thestate of Delaware. The general peripheral distance of the Mesaexceeds 160 miles and it is roughly equidimensional in shape,about 60 miles long in both NE-SW and NW-SE directions. Coal isexposed on all sides and in interior canyons of Black Mesa,which indicates that the coal resources of this area could be farlarger than are currently defined.

The Mesa is an erosional remnant of once more extensivecoal-bearing strata similar in age and closely related to the largercoal resources of the greater Rocky Mountain region. Since coalaccumulation during the latter part of the Cretaceous Period ofgeologic time (70-135 million years ago), earth forces andsubsequent erosion have warped and destroyed coal resourcesand related strata. Black Mesa represents the largest, mostsignificant remnant of this history that is preserved in Arizona.This warping flexed Black Mesa's strata into gentle, elongate,low-amplitude folds. While erosion has stripped strata from thefold crests, these same strata tend to be preserved in the foldtroughs. The Peabody coal reserves are preserved in one of thesetroughs, called the Maloney Syncline.

The thickest remnant of Cretaceous strata preserved in BlackMesa is about 1,700 feet thick at the northeast end of the Mesa.Southwestward, erosion has worn or truncated these strata into acrude, tapering wedge. Because coal is confined to theCretaceous-aged rocks, it is not found more than 1,700 feetbelow the surface.

The Cretaceous rocks have been subdivided into fiveformations, three of which are notably coal-bearing. From thebottom (oldest), these are known as the Dakota Sandstone(coal-bearing), Mancos Shale, Toreva Formation (coal-bearing),Wepo Formation (coal being exploited), and the locally presenthighest unit, the Yale Point Sandstone. Coal from each of thecoal-bearing formations has been mined on a small scale andwas utilized before the introduction of natural gas as fuel forpower plants in Hopi and Navajo tribal communities.

Although coal mining on Black Mesa dates back intoprehistoric times, large-scale mining didn't begin until the 1970s.Prior to this time the record indicates that ten small undergroundmines had been operative in providing fuel for local use and forlimited shipment to Holbrook, Winslow, and Flagstaff. Althoughthe overall total production from these mines probably was lessthan 300,000 tons, they serve a useful function because theyafford some experience with the characteristics of relativelyfresh coal from each of the three coal-bearing formations.

Williams (1951) suggested that Black Mesa coal would not beproduced on a large scale until three problems were overcome:(1) transportation costs, (2) need for a large market, and(3) adequate water supply. In 1966, the Peabody Coal Companyannounced plans to initiate a large stripping operation at thenorth end of the Mesa. Contracts with two power plants call forthe delivery of about 400 million tons of coal over a span of 35years, an average of 11 million tons each year. In one case coal issupplied through a slurry pipeline 275 miles long to the Mohaveplant just across the Colorado River in Nevada, in the other it'ssupplied by rail to the Navajo plant in Page, Arizona. Figure 2shows the total coal-mining, power-generating complex beingdeveloped in the Four Corners region.

Thus, a large market has been developed for power;transportation costs have been handled economically bypipelining and by moving the plants close to the fuel sources;and water requirements are supplied by groundwater that ispumped from an aquifer beneath the coal-bearing Cretaceousstrata. This water is pumped at a rate of about 2,000 gallons perminute from four wells.

Peabody coal reserves occur within about 130 feet of thesurface (this is the maximum stripping depth, which may change

Vol. 5, No.4 FIELDNOTES Page 3

Figure 2. Operating and planned .coal-fueled electrical generatingplants and major coal fields in the Four Corners region.

o '00L--L--J

miles

POWER PLANTS

I. Joseph City2. Mohave (Davis Dam)3. Reid Gordner NO.34. Navajo (Page,Ariz.)5. Kaiparowits6. Four Corners7. Son Juan

~ Known accessible bltuminouscool

~ Known areas of subbiluminous cool

a Major population centers~ Sfrlpping cool mines• Operating or planned cool-powered electric generating plants

PhoenixD

=Tucson

present time there is no transportation available for shipment ofBlack Mesa coal to Arizona's population centers.

ReferencesAveritt, P., and O'Sullivan, R.B., 1969. Coal, in Mineral and

Water Resources of Arizona. Arizona Bureau of MinesBulletin 180, p. 59-69.

Campbell, M.R., and Gregory, H.E., 1911. The Black Mesa CoalField, Arizona. U.S. Geological Survey Bulletin 431-B, p.229-238.

Peirce, H.W., Keith, S.B., and Wilt, J.c., 1970. Coal, Oil,Natural Gas, Helium, and Uranium in Arizona. ArizonaBureau of Mines Bulletin 182, p. 11-41.

Staff, 1974. Arizona Energy Resources. Arizona Bureau of MinesFIELDNOTES, Volume 4, No.1.

Williams, G.A., 1951. The Coal Deposits and CretaceousStratigraphy of the Western pait of Black Mesa. University ofArizona (Tucson), unpublished Ph.D. thesis, 307 p.

Applied Remote Sensing Lab at the U of ARemote sensing is the gathering of

information from such devices as cameras,multispectral scanners, radar, and ther­mal infrared detectors located in aircraftor spacecraft.

Most of us are aware of the usefulnessof conventional aerial photographs. Civiland mining engineers, cartographers,geologists, and others involved in thestudy of the earth's surface have beenusing aerial photographs for many dec­ades. More recently, the technology ofrecording remotely-sensed data from var­ious types of platforms has become sophis­ticated enough to warrant a special field ofstudy commonly referred to as "RemoteSensing."

Many geologists, engineers, and stu­dents in the Tucson area have beenutilizing remote sensing data availablefrom the National Aeronautics and SpaceAdministration (NASA) through the localadministration of the Office of Arid LandStudies at the University of Arizona. Thelibrary of materials, which has steadilygrown, has recently found a new home.The new location for viewing or using thewide variety of available imagery is theArizona Bureau of Mines/College of EarthSciences Remote Sensing Laboratory,Room 334 of the Geology Building on theUniversity of Arizona campus, Tucson.This program is supported by a NASAgrant to the Office of Arid Lands Studies.

The Applied Remote Sensing Program(ARSP) at the University of Arizonaserves a three-fold purpose: (1) to main­tain a library of satellite and high-altitudeimagery, (2) to provide expertise inremote sensing techniques and applica­tions, and (3) to cooperate with local,state, and federal agencies within Arizonain developing and utilizing remote sensingprojects for planning purposes.

Because of the increasing interest inremote sensing techniques and theirapplications, personnel of the ARSP areoften called upon to speak to universityclasses, governmental agencies, and pri­vate meetings. Visual displays of imageryand equipment, as well as visits to the lab,help interested parties become moreknowledgeable with the program and itscapabilities.

Although providing remote sensingexpertise and maintaining a library aretwo important functions of the program,another major effort is developing pro­posals for projects/and working withvarious agencies on. those projects, mostof which involve studies concerning land­use planning and agricultural and water­shed management. As stipulated inNASA's grant to the program, the resultsof completed projects are intended to beused for rational planning decisions.

Many of the non-agency users of remotesensing materials are prospectors andgeologists from private industry. Themodern "explorationist" still uses blackand white and natural color photographsflown at conventional low altitudes for thebulk of his remote sensing imagery needs.Indeed, this conventional imagery is themost detailed scale to analyze and use as abase map for local studies. High altitudeimagery from NASA research aircraftoffers a medium, or intermediate, scale tostudy regional, gross geologic features.Satellite imagery generally has onlylimited application for the "exploration­ist." However, the area covered by asingle satellite image affords an opportu­nity to study certain geologic features,especially those of structural origin, at ascale where the larger features (oftenmissed in more detailed studies) are moreeasily defined.

Other remote sensing research concern­ing nonrenewable resource explorationinvolves color enhancement techniques.Certain tonal registers from film imageryor digital computer data from electronicimagery are enhanced to accentuate thedesired feature. Present research sug­gests that certain rock types and rockalterations zones are discernable underrestricted conditions. Once these tech­niques are refined, exploration targets inremote regions of the world may bedefined prior to surface geologic studies.Contrary to rumors being circulated bysome less informed prospectors, remotesensing satellite imagery is not yet quiteable to pinpoint the location of hidden golddeposits or buried treasure.

Included in the ARSP library's NASA­derived imagery collection are photostaken from high altitude flying aircraftsuch as the U-2, or from satellite plat­forms. Most of the satellite coverage isfrom the Earth Resources TechnologySatellite (ERTS) 1 and 2, now designatedas LANDSAT 1 and 2. There is alsolimited Skylab, Gemini and Apollo cover­age of Arizona. [See pages 4 and 5.]

High altitude flights cover the southernhalf of Arizona and an 18-mile wide corri­dor along the Colorado River betweenLake Mead and Yuma. Both 9 in. by 9 in.color infrared (CIR) and natural colorpositive transparencies, and 70mm multi­spectral black and white (B & W) and CIRpositive films are available for use.

LANDSAT imagery covering the entirestate and portions of adjacent states andMexico is available in 9 in. by 9 in. and70mm B & W positive transparencies. Be­cause the satellite passes over Arizona onan 18-day cycle, at an altitude of 500nautical miles, there is a variety of datesfrom which to choose. continued

I

J

Page 4

Remote Sensing continued

ARIZONA BUREAU OF MINES December. 1975

Figure 3. This mosaic is of a portion of the Cabeza Prieta Mountains in Yuma County. The photographs were taken from high altitude aircraft;note the detail shown. Compare this mosaic with the geologic map in Figure 4. Discrepancies of position of geologic features on the geologic mapdemonstrate the problems encountered when fitting a field geologic-reconnaissance survey to a relatively small-scale topographic base mapsuch as the20Army Map Service sheet (scaleof 1:250,000).

m

Schist

Alluvium

Page 5

oEXPLANATION

Basalt(flows, tuff, and agglomerate)

Granite and related crystallineintrusive rocks

Scole

FIELDNOTES

/1-"

/ Kilometers

/? !

Figure 5. LAN DSAT 1Satellite imagery, band 7 (infrared). The outlined section along the right edge is the sameColorado River shows as a thin black line, dividing the photo above the north arrow. Arizona is on the right of theand Mexico on the lower left. The regional geologic features can be evaluated relative to the study area.

Page 6 ARIZONA BUREAU OF MINES

Entrance to the new quarters of the Geological Survey Branch andPublications Office of the Bureau, located at the southwest corner ofPark Avenue and Second Street. Free parking facilities are on the farside of the building. Arid Lands Studies' display is in the window to theright; on the left the windows contain Bureau of Mines' displays. Thephoto is taken from the western edge of the University of Arizonacampus, looking across Park Avenue; Second Street is to the right.

December, 1975

The library, containing over 22500publications, adjoins the public~tionmap files is a microfiche reader and a

The open door in the center of this photo leads to the Bureau'sdownstairs quarters from the entrance lobby. The CreativePhotography Center is at the extreme right.

These stacks of publications, ready for sale, may be obtained at thefoot of the entrance stairs.

J

Part of a typical geologist's office. Each office contains a draftingtable, desk, and enough wall room for maps and photos.

__ I

Page 7

Phones for the Bureau offices are:Director, W.H. Dresher .. [602] 884-1401Geological Survey Branch 884-2733Mineral Technology Branch 884-1943Publications Sales Office 884-2733

FIELDNOTES

The library's reading area is seen here from the stacks. The ABM librarycontains publications from U.S. Geological Survey, U.S. Bureau ofMines, adjoining state surveys' publications, geological and miningjournals, open-file reports and maps, files on active and inactive mines,and much other material. Though check-out is not allowed, the facilitiesare open to the public for use, and copying can be arranged with localblueprint companies or with the Bureau.

Dr. Dresher, Bureau director, con­tinues to be in Room 134 of theGeology Building on the University ofArizona campus. Offices ofmineralogist Bob O'Haire, miningengineer Dave Rabb, and metallurgistSam Rudy remain in the basement ofthe Mines Building. Metallurgist WaltFisher's office is in Room 125E of theMines Building.

Tom McGarvinl"'cUtJinQ storage area.

material fromwell holes fill

in the Bureau's. Above: core

wells are alsostorage area.

Collapsing Soil-a Geologic Hazard

Page 8

Remote Sensing ContinuedThe lab has received limited area

coverage of Skylab imagery. This imageryis available in 5 in. by 5 in. and 70mmnatural color positive transparencies.Southern Arizona, California, and North­ern Mexico are included in Apollo andGemini coverage. Both of the latterimagery-types have a 70mm positivetransparency format.

Imagery can be used in the lab, andsome coverage is available for circulation.Imagery indices are available and order­ing information can be obtained throughthe Applied Remote Sensing Program.

Also available are microfilm catalogsand some microfilm of U.S. and foreignLANDSAT data. Microfilm readers arelocated in the University library. Viewingequipment in the lab includes a variety ofstereoscopes, large light tables, and acolor-combiner viewer for 70mm imagery.

The Applied Remote Sensing Labora-

by Bruce J. Murphy

One of the consequences of urbangrowth and development in the semi-aridSouthwest is an inevitable upset in thenatural balance of geologic conditions.

Among the responsibilities of the geo­technical engineer is recognizing theseeffects and any resultant geologic hazardsbefore they cause economic and humanloss. Therefore, a thorough understandingof these natural conditions is essential inthese natural conditions is essential inorder that we may judiciously incorporatecorrective measures in engineering struc­tures and adopt building codes for the bestutilization of land.

Unfortunately, usually the only timepeople become aware of the impact oftheir physical environment is when adisaster occurs and they are directlyaffected by the consequence.

Continuing as we have in past issues ofFIELDNOTES, the Geological SurveyBranch of the Arizona Bureau of Mines ispresenting a look at selected geologichazards and how they affect Arizonans.

One that has affected many home­owners in southern Arizona is the problemof foundation failure resulting from collap­sing soil sediments. Collapsing soil, ornear-surface subsidence, can be related totwo geologic processes: the failure ofsediment that is subjected to rapid loss ofvolume upon wetting, load application, orboth; and ground subsidence resultingfrom depression of the groundwater tabledue to groundwater withdrawal. The firstprocess is generally localized, while thesecond may involve an entire valley. Thisarticle is primarily concerned with the

ARIZONA BUREAU OF MINES

tory publishes a newsletter several timesa year, and Carolyn Sawtelle, the editor,will add your name to the mailing list uponrequest. Mail should be addressed toApplied Remote Sensing Laboratory,Geology Building, University of Arizona,Tucson AZ 85721; the phone number is(602) 884-1691.

An assistant is on hand in the lab to aidvisitors in finding the necessary imageryand to furnish information. There is also aprofessional staff capable of applyingremote sensing techniques. to variousfields of study including land-use andnatural resources inventories.

Particular expertise of graduate stu­dent assistants J .S. Conn, John Stelling,and D.A. Miller include urban studies,land-use planning, plant ecology, plantgeography, natural resources, and soilsmorphology. Dr. David A. Mouat, incharge of the lab, has a remote sensingbackground in geomorphology and plant

problem of collapsing soils related to thefirst geologic process as it affects homesin the Tucson area.

Most homeowners find small, insignifi­cant cracks in the walls and foundation oftheir residence due to building materialand/or construction imperfections. Thesesmall cracks, while aesthetically unpleas­ing, are natural adjustments of thebuilding materials to stress/strain rela­tionships and are not normally consideredserious. There are, however, many dwel­lings which have suffered severe settle­ment that has caused large cracks andseparation of walls and foundations,resulting in thousands of dollars indamage. Questions often pondered by ahomeowner who encounters serious struc­tural failures in his own residence are:what is causing this particular problem?;are local officials aware of the seriousnessof this phenomena?; how can it be fixed?;what could have been done in the originalconstruction of the building to preventthis problem?

During the past 15 years, much re­search has been devoted to the mechanismand origin of collapsing soils, yet little ofthis valuable information has been appliedto our own semi-arid environment.Thou!;h the exact reason for a soil tocollapse is still poorly understood, mostexperts agree that moisture content,overburden load, and type of naturalcementation (material that bonds the soilgrains together) are chief factors causinginstability.

When water percolates through asediment that has been undersaturated ordevoid of liquid since its formation, thesupporting material in the voids between

December, 1975

ecology.Although physically separated from the

lab, the Geological Survey Branch of theArizona Bureau of Mines is available toassist in interpreting remote sensing dataas it pertains to the geology and nonre­newable resources of Arizona. Interestedparties should contact John Vuich, aBureau geologist who has considerablebackground using remote sensing data forengineering and economic geology studies.

A digitizer, densitometer, and zoomtransfer scope are available for use in theLab for Remote Sensing and ComputerMapping, another remote sensing labora­tory on the University campus. Dr. BillRasmussen, a research professor in re­newable natural resources, is in charge ofthe lab, which is located in the BioscienceEast building, Room 203. For additionalinformation concerning the use of thislab's equipment, call Dr. Rasmussen at(602) 884-3751.

These photos of a house's brick wall showtensional cracks with up to l-inch displace­ment.

_J

UniversityTerrace

Page 9

ments were deposited in water-deficientenvironments. Soils like these are likely toexperience consolidation when pressure isapplied.

Consolidation tests indicate that theUniversity terrace has been subjected topreconsolidation or prior loading whereasthe younger terraces are either normallyconsolidated or slightly underconsoli­dated. Field observations indicate that theUniversity terrace is the least prone tocollapsing soil problems. On the otherhand, the Cemetery terrace, and to alesser degree the Jaynes terrace and thefloodplain, are subject to the most severesettling within the Tucson area. Thoughthe degree of foundation failure varieswidely, problem-prone areas in the Tuc­son region are located on or near theSanta Cruz, Pantano wash, and Rillitofloodplains and adjacent terraces (seephotographs). Foundation settling of up to2lf2 feet has been reported on someresidential lots, and such major structuresas the high-rise Home Federal Buildinghave developed some settling problemsrequiring costly remedial measures.

For existing structures, two soil stabili­zation methods are generally practiced tocompensate for a soil's inability to bearapplied loads.

One remedial method is known asunderpinning (fig. 7), an expensive anddifficult operation that reinforces thefoundation with a new support. Under­pinning requires that the foundation beexcavated and slowly raised by largehydraulic jacks. A new foundation ofgreater width and depth is then setunder each of the existing footings.

The second method uses injection of asoil cement to fill voids and displace soil

FIELDNOTES

plain-like valleys. The Tucson basin istheorized to have formed during early/mid-Tertiary time (25 million years ago).During this time, massive blocks of rockmoved vertically relative to one another,forming high mountainous areas andcontrasting low valleys. These valleyswere later filled to depths of 2,000-8,000feet with weathered alluvial material fromthe uplands. During this basin-fill process,the Tucson basin was characterized by aninternal drainage system. In the PlioceneEpoch (11-13 million years ago), appar­ently the Santa Cruz River cut northwest­erly between the Tucson Mountains andthe Santa Catalina Mountains. Thischanged the drainage system into athrough-flowing system, and erosion ofthe basin began. The Santa Cruz drainagesystem, which is still actively eroding thebasin today, formed broad river terracesand scoured alluvial fill along mountainfronts.

In other areas, collapsing soils havebeen associated with some recent ero­

i sional surfaces and river terraces, such asthose found in the Tucson Basin. Accord­ing to many workers, collapsing soils aregeologically recent, loosely-packed (up to40% void space), and generally under­saturated with water. Smith (1938) andPashley (1966) have mapped the recentterrace deposits within the Tucson areaand have classified them from oldest toyoungest as the University, Jaynes, andCemetery terraces. These terraces aretopographically higher than the presentfloodplain (bottomland). (See fig. 6.) Someof these terrace sediments consist of low­density, organic-rich silts, sands, clays,and gravels. The low density is the resultof small voids developed as these sedi-

/

university Terrace

/

Cemetery Terrace

<:;':;:::~:::""'" '. (Jaynes Terrace"': ..: .. :: :..: .. :- .:::.~::.:::::::.::: .. :.:::'.:... Bottomland ,' "':'.:;:

,:i'@:~~ili,~fJl;~~;i;;g:;sw·ili"z;~~*~~~~~~I~;j';~l@mp,

on basin lies within the Basinphysiographic province whichized by numerous mountain'rig abruptly from broad,

s (usually clay) are easilyl'dissolved. When a structural

Eldon this material (0.6 ton/sq.Illal house to 1.0-2.0 ton/sq. ft.strial plant), the soil fabricto this new stress condition.

ble soil compacts more easilyume loss translated verticallyfeet may result in visible

n the surface. This settlingcan be rapid, taking only a few

t may take several years tohe important step is to recog­

'1 conditions within the area anditable scheme to alleviate the

flo floor was extensively damagedtial cracking.

Page 10 ARIZONA BUREAU OF MINES December, 1975

• 0 CONTINUOUS• • CONCRETE

'. .....-- UNDERPINNING

SHORING, ~ •..........._".,

-k----..."..COMPACTED'" ~ BACKFILL

NEW ....--~BASEMENT ••

I~S;:::U~BG~R.:::A:;:;D~E~L.-.--l~ ~~ ,.

L...-

Figure 7, A cross section of the continuousunderpinning method of stabilizing existingfoundations.

grains (fig. 8). This method involvesraising the foundation footings and inject­ing a low-moisture, non-plastic mixture ofsoil and cement down a grout pipe atspecified depths. The process is repeatedin several pipes until the volume of soilunderneath the footings has been filledwith properly-spaced balls of the soil!cement mixture. The increase in volumeof the soil in the region where groutingcement is injected causes adjacent soilgrains between the balls to compact. This

L..I-~__ ••

preconsolidated pad with a reinforcedfoundation; localized soil settlement wouldthen be greatly reduced.

As the population of our area continuesto experience rapid growth, the impor­tance of detailed soil surveys becomesessential. The introduction of denserhousing developments and heavier struc­tures warrants a greater understanding ofthe soil environment and its limitations.Costs of such studies are often much lessthan the costs of remedial measures afterdamage has occurred. Also, it is possiblethat foundation preparation suggested bysuch studies might eventually represent aform of damage security approved byinsurance companies.

References

Pashley, E.F., 1966. Structure and strati­graphy of the central, northern, andeastern parts of the Tucson basin,Arizona. University of Arizona, Ph.D.thesis.

Smith, G.E.P., 1938. The physiography ofArizona valleys and the occurrence ofground water. University of ArizonaAgricultural Experiment Station, Tech­nical Bulletin 77, 91 p.

These maps are of terraces and erosionsurfaces within the Tucson area, The Ceme­tery unit appears to have the greatestpotential for foundation failure.

tends to stabilize the soil along a linearzone surrounding the grout holes.

Both of these methods are relativelyexpensive, and the resulting soil stabilitydepends upon the skill and experience ofthe contractor.

Perhaps the best solution, however, liesin the fact that collapsing soil problemscan be avoided by recognition of this soilcondition prior to construction, and quali­fied testing by soil and foundation expertscan determine potential foundation prob­lems. When these conditions are found toexist the structure should be built on a

Figure 8. A demonstration of the soil-cementinjection method of stabilizing damagedfoundations.

EXPANSIONZONE

COMPACTIONZONE

FLOOR SLAB

:-:::BRICK WALL

1== -CONCRETE FOOTING,.,, ...'0

ACCESSPIT

GRADE

EXPLANATION

------ Contact Between GeomorphicUnits

Jaynes Terrace andErosion Surface

University Terrace andErosion Surface

Flood Plain

Cemetery Terrace andErosion Surface

Present Alluvial Channel

Vol. 5, No.4

Arizona Departmentof

Mineral Resourcesby John H. JettDMR Director

Though the Department of Mineral Re­sources was officially created on March 1,1939, its true beginning was in February1938 when the first council of the ArizonaSmall Mine Operators Association wasorganized. In order to understand thescope of the activities of the ArizonaDepartment of Mineral Resources, it isnecessary to review the reasons for itscreation.

Between 1935 and 1937, as indicated inthe Minerals Yearbook published by theU.S. Bureau of Mines, the number ofsmall, producing mines in Arizonadropped from 2,200 to 1,200. This alarm­ing drop was of grave concern to thoseinterested in mining, and it gave impetusfor the organization of the Arizona SmallMine Operators Association. Over theyears the "small mine operator" classifica­tion has come to include prospectors,operators, exploration personnel, rock­hounds, mineral collectors, and manyothers with an active interest in themining industry of Arizona.

The initial growth of the organizationwas rapid and by August, 1939 there were46 cOl,mcils and 2,100 members. The basicorganization consisted of a state head­quarters for coordinating the work of theindependent and autonomous councilswhich were located in various activemining camps and other communities.

The first annual state meeting was heldin Prescott, in August, 1938; approxi­mately 2,000 members were present.Discussion at this first state meetingindicated that the small mine owners'major problems were economic, and thatto arrive at a solution a greater degree ofstudy, research, and field technical assis­tance would be necessary than thatpossible with a volunteer group. It wasbelieve that such a program would requirethe full time and effort of a paid, properlyequipped and trained staff, but that theresults of such work would benefit theentire state. As a result, a plan for aDepartment of Mineral Resources wasdrafted.

In February, 1939 State RepresentativeBen O'Neil of Ajo introduced a bill,sponsored by the Arizona Small MineOperators Association, establishing aDepartment of Mineral Resources. Thisbill was passed unanimously by bothhouses of the Legislature. When GovernorRobert T. Jones signed the bill on March1, 1939, he characterized it as "the most

FIELDNOTES

constructive legislation that has beenenacted."

The bill provided for the Department tobe controlled by a board of governors,consisting of 5 members from variousparts of the state appointed by theGovernor for 5-year terms. The Board ofGovernors would serve without compen­sation, other than reimbursement foractual expenses of attending meetings.They would outline the policies of theDepartment and employ the director, whowould in turn employ field and office staffconsistent with the Department's appro­priation and the policies of the board.

Charlie Willis became Chairman of thefirst board, and Sam Coupal was ap­pointed the first director. With theexception of the years between 1944-51,Mr. Willis remained chairman until hisdeath in 1968. The directors succeedingCoupal were, in order: Charles H.Dunning, R.LC. Manning, Frank P.Knight, and the present director, John H.J ett. As required by the statutes, all wereregistered mining engineers.

During the Department's first year,four mining engineers were hired andtrained as field engineers. All the diverselaws and regulations governing mining onlands within the state were compiled andstudied. A major part of the effort duringthe first year was devoted to a resourcessurvey in which information on manypartially developed prospects, mines, andmineral deposits of the state was gath­ered. However, because of a continuingshortage of personnel, this project has notbeen completed. Also, a study was madeof the problems of the "small miner," andextensive field service was provided tohelp prospectors and small miners withtheir individual problems.

Another early phase of the Depart­ment's work was the gathering of thebasic economic information required fromtime to time for compiling reports andmaking studies. Every effort is made tokeep this data up to date; its value hasbeen proven many times when it wasnecessary to prepare briefs on miningsubjects.

Surveys of special projects such asroads to serve isolated mining areas,custom milling plants, custom smelters,and numerous other mining-related prob­lems, were made by the Department uponrequest. One interesting and importantproject was a study and survey made ofdust conditions in the mining industry andthe relationship to silicosis as a compens­able industrial disease.

Many conferences were held in theearly days with Dr. T.G. Chapman, thendirector of the Arizona Bureau of Mines,in order to more closely coordinate thework of the Department and Bureau. Oneof the more important results of theseconferences was the publication of a series

Page 11

of information circulars on the lesscommon metals and minerals.

Another phase of the cooperationbetween the Department and Bureau wasthe establishment of an ore testingdepartment in the Bureu to serve thesmall mines. With the Department ofMineral Resources supplying field work,and the Arizona Bureau of Mines doingresearch, flow sheets were designed forbetter milling results, at only a smallcharge to the miner.

The work of the Department wascarefully planned in its earlier years toavoid overlapping or duplicating the workof the Arizona Bureau of Mines. TheDepartment's activities were limited tothe economic side of mining and to fieldproblems confronting the small miner andprospector.

The early work and cooperation be­tween the two agencies clearly demon­strates their differences. The Bureau is ofa scientific and research nature, and theDepartment is more or less promotionaland concerned with problems that aremore economic and technical than scienti­fic in character.

It must be remembered that theDepartment was created as a serviceorganization to the mining industry of thestate; the only thing that has changedthrough the years is the type of servicerequired to "promote the mineral indus­try" and assist interested or mineral­oriented people.

The call for strategic and criticalminerals by the federal governmentduring World War II found the Depart­ment well equipped and ready to giveimmediate service. During these waryears mining became so complicated andwas beset by so many restrictions andregulations that a liaison man from theDepartment was stationed in Washington.The Director of the Department became aconsultant to, or member on severalFederal agencies, including the WarProduction Board.

During the immediate post-war years,many new problems arose for the mineralindustry that required new types of helpfrom the Department of Mineral Re­sources. Problems that involved theDepartment included the critical mater­ials stockpiling act; premium price planfor copper, lead, and zinc; federal govern­ment contract terminations with the smallminers; demand for uranium; phasing-outof RFC loans; suspension of Copper Tariff;mining law revisions; and the developinginterest in nonmetallic minerals.

In the 1950s, new problems includedincreased costs (without increased metalprices); the Korean war and its relatedshortages; and a change in public opiniontoward mining, which created a need forpublic relations. Additional changes wereincreased uranium prospecting; emer-

Page 12

gence of manganese and tungsten asmajor metals; the decline of lead-zincmining; availability of federal DMEAloans; revision of mining laws on statelands; and the establishment of theMineral Museum as a full-time division ofthe Department. Toward the end of the1950s, production of copper was curtailed,and much work was being done on long­range mineral policies, tariffs, and similarproblems for submission to federal agen­cies. The government terminated themanganese stockpiling program, whichclosed the manganese mines. During thiseyears, the Department maintained fieldoffices in Tucson, Prescott, and Kingman,as well as the main office in Phoenix.

During the 1960s, much time was spenton developing data for submission atcongressional hearings on stockpiling ofsurplus minerals; tax laws; depletion; goldand other mineral subsidies; silver pur­chase act; laws, regulation, and adminis­trative procedures pertaining to mineralrights on public lands; the WildernessAct; import controls; gold, silver, andmonetary policy; land withdrawals; andthe creation of the Public land LawReview commission.

During these years the Departmentwas called upon many times for assistanceto state agencies on mining questionsrelating to property tax studies, parkareas, right-of-way, industry develop­ment; economic research, history, em­ployment, and use of State lands. Federalagencies called on the department withquestions or problems relating to publiclands, mining statistics, mine loans,exploration loans, old and new mines,mining costs, stimulation of copper pro­duction, use of water, and the study of

ARIZONA BUREAU OF MINESTHE UNIVERSITY OF ARIZONA

845 NORTH PARK AVE.TUCSON, ARIZONA 85719

ARIZONA BUREAU OF MINES

strip and surface mining.Although many of the problems of the

small miner still exist, and a constantdemand for field service is still beingmade, additional problems arose in the1970s: awareness of "environment" and"ecology"; land-use planning; curtailmentof copper smelter capacity; the closing ofcustom copper smelters and most of thelead-zinc smelters; land withdrawals;government rules and regulations; andinflation; all produced many additionalhardships for the small miner.

The circumstances existing in 1939 thatresulted in the creation of the Departmentof Mineral Resources have changed con­siderably. The number of small miners hasdecreased, but those individuals havebeen partially replaced by explorationcompanies. At this time there are morethan 55 active exploration companies inArizona. Even though the small miner hasdecreased in number, he is perhaps moreimportant than ever; though fewer innumber, he does a bigger job and stillrepresents a major claim owner. This iswhy the Department continues to workvery clos.ely with the Arizona Small MineOperators Association.

Mineral economics, proposed majorrevisions of the Federal Mining Laws,expanding markets for nonmetallics, andproposed restoration and reclamation ofmined areas are all problems causing theexplorationists to call for more help fromthe Department of Mineral Resources. ­in ways never imagined when the Depart­ment was created.

A new' area of the mineral industry, andone of major importance because of theinvolvement of so much. of the public,consists of the rockhound (hobbyist, or

December, 1975

amateur mineralogist) and the recrea­tional or weekend prospector. Both groupshave a considerable economic impact onthe state, and because they are notusually technically trained, they needconsiderable professional help. The De­partment of Mineral Resources is theirrepresentative within the state.

Publications of the Departmentof Mineral Resources

Publications of the Department ofMineral Resources are available free ofcharge; a complete list of the publicationswill be sent upon request. The mailingaddress is:

Arizona Dept. of Mineral ResourcesMineral BuildingFairgroundsPhoenix, AZ 85007

Some of the publications are:Laws and regulations governing mineral

rights in Arizona;Pertinent data for new mining operations;Patenting a mining claim;Environmental guidelines for exploration;Annually revised lists of active mines

within the'state, exploration companies,land ownership, rockhound clubs, andmany other subjects.

FIELDNOTES

Volume 5, No.4 Dec. 1975State of Arizona

Governor Hon. Raul CastroUniversity of Arizona

President John P. SchaeferArizona Bureau of Mines

Director William H. DresherEditor Judi Goodpaster

ARIZONA BUREAU OF MINESTHE UNIVERSITY OF ARIZONA

TUCSON, ARIZONA

NON·PROFIT ORG.

u.s. POSTAGEPAID

PERMIT NO. 190TUCSON, ARIZONA

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