Correlation and interpretation of paleosols and loess across EuropeanRussia and Asia over the last interglacial–glacial cycle

Nathaniel W. Rutter,a,* Dean Rokosh,a Michael E. Evans,b Edward C. Little,c Jiri Chlachula,d

and Andrei Velichkoe

a Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3b Institute for Geophysical Research, University of Alberta, Edmonton, Alberta, Canada T6E 2G1

c Canada-Nunavut Geoscience Office, Box 2319, Iqaluit, Nunavut, Canada X0A 0H0d University of Zlin, Palaeoecology Laboratory, Zlin 76272, Czech Republic

e Institute of Geography RAS, Laboratory of Evolutionary Geography, Staromonetny Lane 29, Moscow 109017, Russia

Received 4 November 2002

Abstract

Loess-paleosol sequences of the last interglacial-glacial cycle are correlated from European Russia to central Siberia and the ChineseLoess Plateau. During cold periods represented by marine oxygen isotope stages (OIS) 2 and 4, loess deposition dominated in the RussianPlain and the Loess Plateau. In central Siberia, loess deposition took place also, but five to seven thin, weakly developed paleosols areidentified in both stages. OIS 3, in the Chinese Loess Plateau near Yangchang, consists of a loess bed that is flanked by two weaklydeveloped paleosols. At Kurtak, Siberia, OIS 3 is represented by two distinct, stacked paleosols with no loess bed separating the paleosols.In the Russian Plain, OIS 3 consists of a single, possibly welded paleosol, representing upper and lower stage-3 climates. Brunisols andChernozems dominate the profiles in China and Siberia, whereas Regosols, Luvisols, and Chernozems are evident in the northern andsouthern Russian Plain, respectively. OIS 5 is represented in China and the Russian Plain by pedo complexes in a series of welded soils,whereas in contrast, the Kurtak site consists of six paleosols with interbedded loess. The paleosols consist largely of Brunisols andChernozems. Although the three areas examined have different climates, geographical settings, and loess source areas, they all had similarclimate changes during the last interglacial-glacial cycle.© 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Keywords: Paleoclimate; Loess; Paleosol; Last glacial maximum; Quaternary; Russian Plain; Siberia; Isotope stage; Chinese loess plateau; Stratigraphy

Introduction

In the early sixties, Troy Pewe was the senior author’sMasters program supervisor at the University of Alaska.Although my thesis concerned the flow of Gulkana Glacier,Troy’s broadly based, eclectic view of the Quaternary en-sured that his students would take a holistic view of theperiod when solving scientific problems. His constant ques-tion to us was “Do you understand the big picture?” Thefield trips around Fairbanks instilled in me an appreciationof the importance of loess in Quaternary studies. Later, Troy

took his loess investigations to China. This contribution is acontinuation of his legacy.

In the past 12 years, we have investigated Quaternaryloess-paleosol sequences in China, Siberia, and the RussianPlain as part of Canada’s project on Climate System Historyand Dynamics. The objective here is to correlate and exam-ine high-resolution loess-paleosol sequences at three loca-tions covering more than 60° of longitude (Fig. 1). Eacharea has different geographical settings and modern climate,and all are key areas for studying loess deposition andpaleosols. The sediments at all three sites span a similartime interval and are: (1) three sections at Likhvin, Go-lolobovo, and Korostylievo in the Russian Plain (Lat. 56°N,Long. 36°E; 55°N, 38°E; and 52°N, 42°E, respectively); (2)

* Corresponding author.E-mail address: nat.rutter@ualberta.ca (N.W. Rutter).

R

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a 35-m section at Kurtak in south-central Siberia, Russia(54°N, 92°E); and (3) two sections at Yangchang and Yulinin the central Loess Plateau, China (37°N, 110°E; and 38°N,110°E, respectively).

Physiographic setting

Likhvin and Gololobovo (Fig. 1) are located about 125km southwest and 125 km southeast of Moscow at eleva-

tions of 150 and 170 m asl, respectively, in the RussianPlain. Both the Likhvin and Gololobovo sites lie along thenorth flank of the Oka River. The Korostylievo site islocated on the south bank of the Vorona River at about100 m asl, approximately 435 km southeast of the Go-lolobovo (Velichko et al., 1997; Little, 2002).

The 35-m section at Kurtak (Fig. 1), near the geographiccenter of Asia, lies at an elevation of about 250 m asl.Kurtak is located on the north flank of the Yenisey Riverwithin the Northern Minusinsk Basin. The Altay-Sayan

Fig. 1. Index map of the sites discussed in the text. The map is a modified version downloaded from the University of Texas at Austin, Perry Castaneda Libraryat http://www.lib.utexas.edu/maps/asia.html.

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Mountains to the west, along with the Eastern Sayan Moun-tains and the Tannu Ola Range to the east and south,respectively, orographically isolate the Kurtak area fromsoutherly climatic influences (Chlachula, 1995).

Yanchang and Yulin (Fig. 1) are located in the centralLoess Plateau of China, each at an elevation of about1200 m asl. The Tibetan Plateau and the east-west trendingQinling Mountains are about 350 km south of Yanchangand largely block the transport of dust further southward(Liu, 1985). The deserts of China are located to the northand west of the Loess Plateau (Liu, 1985).

Loess sources

The paleogeography of the three areas presents an interest-ing contrast in glacial landscape and dust sources during thelast glacial period (marine oxygen isotope stages [OIS] 2, 3,and 4). The Likhvin, Gololobovo, and Korostylievo sites arelocated in the Russian Plain near numerous river valleys andwere about 250 to 500 km south of the southern limit of theFennoscandian Ice Sheet during the last glacial maximum(Velichko et al., 1997; Little, 2002). Kurtak is situated withina mountain range, where there is evidence for the presence ofalpine glaciers during the last glaciation, although nonereached the Kurtak area. There is no evidence of glaciers in theLoess Plateau or the northern deserts of China.

Loess on the Russian Plain forms a blanket that covers anarea of over one million square kilometers. It is derivedfrom the northern alluvial and lacustrine plains that formedin front of the advancing and retreating Pleistocene icesheets (Velichko, 1990). At Kurtak, loess is located alongthe terraces of the Yenisey River and is derived from theupper Yenisey valley, and from local bedrock (Chlachula etal., 1997). Loess in China comes largely from the northerndeserts (Liu, 1985), and to a lesser degree from cold, south-erly winds emanating from the Tibetan Plateau (Fang et al.,1999) as well as from the upper-level Westerlies (Zhang etal., 1996).

Modern climate

According to the Koppen-Geiger climate classificationsystem (Geiger and Pohl, 1954), Likhvin, Gololobovo, andKorostylievo are classified as Dfb climates (humid conti-nental with severe winter, no dry season, warm summer).Kurtak has a Dwc climate (subarctic, continental, dry win-ter, cool summer) and Yanchang and Yulin are classified asa BSk climate (mid-latitude, cold semiarid steppe). Precip-itation and temperature data for the European Russia andSiberian sites are derived from major cities near the sites(NOAA, 1991). Mean annual precipitation at Moscow isabout 630 mm (125 km north of Lihkvin and Gololobovo),with precipitation slightly higher during summer monthsthan winter months. Average January and July temperature

are about �11° and 18°C, respectively (NOAA, 1991). AtVolograd (350 km southeast of Korostylievo) mean annualprecipitation is about 310 mm and is highest during thewinter months. January and July average temperatures areabout �12° and 24°C, respectively. Korostylievo is abouthalf the distance between Moscow to Volograd. Mean an-nual precipitation at Krasnoyarsk, about 100 km northeastof Kurtak, is about 490 mm, with most of the precipitationoccurring during the summer months. Average January andJuly temperature are about �17° and 18°C, respectively(NOAA, 1991). Kurtak is located in an active permafrostarea. At Yanchang, mean annual precipitation and temper-ature are about 550 mm and about 8°C, and Yulin’s about400–450 mm and about 7° to 8°C with precipitation occur-ring principally during July to September of the summermonsoon season (Zhao, 1986).

Methods

Grain-size analyses from the Russian and Siberian siteswere performed at the University of Alberta on a Micro-meritics Sedigraph 5100 after removal of organic materialand carbonate. At present, grain-size analyses at Kurtakhave been restricted to about every 20–30 cm and every 30cm to 1 m in the Russian Plain sites. Aliquots of sampledmaterial for magnetic susceptibility analyses were looselypacked into 8-cc plastic boxes and measured on a Barting-ton MS2 meter at the University of Alberta. At Yanchangand Yulin, samples were taken every 5–10 cm. Grain-sizeand susceptibility analyses were performed in China at theAcademy of Sciences, Beijing. Susceptibility was deter-mined in the lab on an �50-g bagged sample, using aBartington MS2 susceptibility meter. Grain-size analysiswas performed on a PRO-700 SK Laser Micron Sizer afterremoval of organic material, carbonate, and pedogenic iron.The paleosols were identified by field characteristics andmicromorphology. Some additional analyses (names, com-position, geochemistry) were prepared at the Institute ofGeography, Russian Academy of Sciences.

The soils were classified according to the Canadian Sys-tem of Soil Classification (Soil Classification WorkingGroup, 1998). In general, the Canadian System correspondsmore closely to systems used in Europe and Asia than withother classifications. The paleosols were identified by fieldcharacterisation and micromorphology.

Chronostratigraphy

Chronostratigraphy at the three sites is determined by acombination of 14C dates, optically stimulated luminescence(OSL), thermoluminescence (TL), paleontological data, andcorrelation to other nearby well-dated sites. Little et al. (inpress) have applied the OSL dating method to the Likhvin,Gololobovo, and Korostylievo sites in the Russian Plain

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(Fig. 2). At Kurtak a single date of 30,400 � 700 14C yrB.P. was determined on wood from a paleosol located atabout 10 m depth (Fig. 3). This paleosol is well correlatedthroughout the area to other dated sections that exhibit 14Cdates of about 30,000–35,000 yr B.P. (Chlachula, 1995;Chlachula et al., 1997). The paleosols from 16 to 21 m atKurtak were assigned to the last interglacial based on cor-respondence with regional rodent and mammoth taxa, thepresence of Paleolithic (Mousterian) stone tools, along withstratigraphic position, and the advanced degree of soil de-velopment (Chlachula et al., 1997). Chlachula (1995) andChlachula et al. (1997) correlated the Kurtak pedo complexto the Sukholozhskiy pedo complex (Drozdov et al., 1991)and the Kamenolozhskaya paleosol, both of which wereassigned to OIS 5. The section at Yanchang has previouslybeen correlated to Yulin (Fig. 4) (Sun et al., 1998; Ding etal., 1999) and Weinan (Liu et al., 1995), where the lastinterglacial-glacial cycle is chronologically well-con-strained by 14C and thermoluminescence dating.

Sections in the Russian Plain

(a) Likhvin

The Lihkvin section has a long history of investigations(Sudakova, 1993; Bolikhovskaya, 1995). It is about 8.25 m

thick (Fig. 2). The upper 2 m consists of the present-dayBrunisol over colluviated loess exhibiting discontinuousbanding and rare, granule-sized clasts. A 6-cm localizedlayer of charcoal fragments, together with oxidized graniticclasts from 2.10 to 2.16 cm, suggests the presence of a fire pit.The charcoal has been dated 14C at about 2700 14C yr B.P.

A weakly developed cumulic Regosol underlies colluvi-ated loess within OIS 2 (Little et al., in press). Below thissoil is a loess bed (Desna loess horizon; Velichko, 1990)which has a basal OSL date of 29,000 yr B.P. (Little et al.,in press) indicating deposition during the last glacial max-imum (OIS 2). Underlying this loess is a cumulic Regosol(Bryansk paleosol; Velichko, 1990) that testifies to dustdeposition contemporaneous with formation of the soil. 14Cdates of this soil obtained from various profiles give an agerange between 24,000 and 32,000 14C yr (Chichagova andCherkinsky, 1988; Velichko, 1990). We suggest that theBryansk paleosol corresponds to the warm periods of OIS 3.The ice-wedge pseudomorphs belonging to the Vladimircryogenic horizon (Velichko and Nechaev, 1984; Morozovaand Nechaev, 1997) deformed this paleosol and reflect thebeginning of the subsequent cold periods of OIS 2. Arelatively thin (1.5–1.8 m) loess bed (Khotylevo loess ho-rizon; Velichko, 1990) on which the Bryansk paleosol de-veloped corresponds to OIS 4, dated with an OSL date of70,000 � 7000 yr B.P.

Fig. 2. Lithostratigraphic and pedostratigraphic logs of the Russian Plain sites. Likhvin and Korostylievo diagrams represent the larger, upper portions ofsedimentary successions whereas the Gololobovo section diagram is derived from three smaller composite sections. Except where noted, ages were obtainedfrom optical dating techniques [cf. Little et al. (in press); Little (2002)]. The “� units” are used to characterize lithologic units and represent average grain-sizevariations based on textural analyses.

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Below the loess of OIS 4 is the Mezin pedo complex,corresponding to the different substages of OIS 5. This pedocomplex includes two phases of soil formation. The upperphase consists of a paleosol with a dark humus horizon(Ah-B) corresponding to substage OIS 5a and perhaps sub-stage OIS 5b, formed during the Krutitsa interstade (Veli-chko, 1990). According to T.D. Morozova (personal com-munication, 2002), this chernozem-like paleosol could formin a cold steppe environment. The lower of the two pa-leosols exhibits a profile Ae-Bt1-Bt2 identified as a Luvisol,suggesting strong pedogenic influence under forested con-ditions (Morozova, 1981). The lowermost unit is interpretedas a glacial lacustrine environment contemporaneous withdeglaciation of the region (Sudakova, 1993; Little et al., inpress). Cryoturbation has deformed the fine silt and claylaminae of this unit.

(b) Gololobovo

The surface soil at Gololobovo is a Luvisol residing in aforest to forest-steppe environment (Fig. 2). Underlying the

modern soil is a bed of loess with a basal OSL date of�28,000 yr B.P. representing OIS 2. In some places thelower part of this bed contains the weakly stratified siltyclay. In other places this loess-like sediment is more homo-geneous. The stratified layer is not observed at the other twoRussia Plain sites, so a localized pond or lake is postulated.Beneath this bed, correlated with the Desna loess horizon, isa paleosol with gradational contacts from about 3.2 to 3.7 m.Based on micromorphology, field observations, and labora-tory data the paleosol is interpreted as a cumulic Regosolforming in a steppe to forest-steppe environment. This pa-leosol may correspond to late warm period of OIS 3 andtherefore the Bryansk paleosol. It formed on a 1.2-m-thickloess bed. An OSL date of about 34,000 yr B.P. was ob-tained near the middle part of this loess bed. Underlying theloess bed is a single paleosol that corresponds to the Mezinpedo complex, i.e., OIS 5. It consists of Ahe and Bt hori-zons, suggesting this soil belongs to the Luvisolic Order andformed under moist forested conditions. Unlike the Lihkvinand Korstylievo sections, only a single last interglacialpaleosol is observed at Gololobovo.

The basal sediments at this site are interpreted as, fromtop to bottom, loess, colluviated loess, and loess-like sedi-ments (so called “blue loess”) that accumulated in ponds,corresponding to the last part of Middle Pleistocene (Little,2002; Velichko et al., 2000). Two OSL dates of 117,000 �21,000 and 122,000 � 15,000 yr B.P. were obtained 1 mbelow the Mezin soil complex.

(c) Korostylievo

The modern soil at Korostylievo is an orthic brownChernozem that formed within the modern forest-steppeenvironment (Fig. 2). The soil overlies a 1-m-thick loessbed that correlates to the last glacial period OIS 2. Theunderlying loess-paleosol unit corresponds to OIS 4 and 3,respectively. An OSL date of �57,000 yr B.P. was deter-mined from loess just below the paleosol. The loess exhibitsan increase in blocky structure upward culminating in theformation of an eluviated brown Chernozem that corre-sponds to the warm period(s) of OIS 3. During the lastinterglacial period, OIS 5, two relatively well-developedChernozemic soils are observed with the lower soil beingbetter developed based on field, laboratory, and micromor-phological analyses. We classify the lower paleosol as adark-brown Chernozem and the upper OIS-5 paleosol as abrown Chernozem. The three paleosols of OIS 5 and 3 showa progressive weakening in soil development up-sectionsuggesting that higher temperatures and moisture occurredearly during OIS 5 with progressively weaker soil formingconditions occurring during late OIS 5 and 3. Loess accu-mulation rates were greatly reduced during OIS 5 (Little,2002). The data suggest that significant pedogenic over-printing of OIS-5 soils that developed in OIS 6 may haveoccurred. This is in striking contrast to the cumulic soils ofthe last interglacial period in China and Siberia where loess

Fig. 3. Magnetic susceptibility, grain-size variations, and stratigraphicprofile at Kurtak, Siberia. The dashed line represents the grain-size dataand the solid line the magnetic susceptibility. CH, Chernozem; BR,Brunisol; GR, Gleyed Regosol; CL, Colluviated loess; L, Loess.

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deposition continues during warm periods. This overprint-ing is yet unexplained.

Correlation of the Russian Plain Sediments

The Russian Plain covers a large area, so these sites offeronly a glimpse of the complexity of the Russian Plaingeology during the last interglacial-glacial cycle (Velichkoet al., 1997). The OIS-2 loess, below the modern soil (Fig.2), is continuous throughout the area and is thickest at thewestern Lihkvin site. The ponding at Gololobovo attests to,perhaps, the presence of brief weak warm periods during thelast glacial cycle, although a regional pattern of lake sedi-mentation during this time is not presently observed. TheBryansk soils corresponding to OIS 3 appear to have devel-oped in a cold steppe environment and exhibit weakerdevelopment than the modern and last interglacial soils inall three locations. The OIS 3 soil is best developed in thesouthern-most site of Korostylievo, where it is an eluviated

brown Chernozem. More than fifteen 14C dates have beenderived from the paleosol ranging from 24,000 to 33,00014C yr B.P. (Chichagova and Cherkinsky, 1988; Velichko,1990; Velichko et al., 1997). Below this soil is a loess bedcorresponding to OIS 4, although the presence of OIS 4 atGololobovo is not confirmed. The top of OIS 4 according toMartinson et al. (1987) is about 59,000 yr and may be asyoung as 50,000 yr according to Liu et al. (1995, 1998). Thetwo OSL dates �117,000 and 122,000 yr B.P. provide alower limit for the age of the bed and could correspond toloess deposited during the late Middle Pleistocene.

During the last interglacial period, two soils are observedat both Lihkvin and Korostylievo. In both cases, the lowersoil is better developed. At Korostylievo, the soils are Cher-nozemic and formed in a steppe environment, whereas thesoil development at Lihkvin is related to forested conditionsor perhaps a forest-steppe environment. The OSL dates atGololobovo suggest that the soil formed during the late, lastinterglacial period and, similar to the nearby Lihkvin site,was developed under forested conditions.

Fig. 4. Correlation between the Yulin and Yanchang sections. Yulin TL dates are from Sun et al. (1995), while the isotope stage dates are from the age modelof Liu et al. (1995, 1998).

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Sections at Kurtak, Siberia

A striking feature of the Kurtak pedostratigraphy is therelatively weak Brunisolic and Regosolic soils that arepresent in the upper portion of OIS 4 and the lower portionof OIS 2 (Fig. 3). There are no less than seven soils ob-served in OIS 4, and 5 soils in OIS 2.

The paleosol representing OIS 3 is actually two soils,with a Brunisol overlying a parkland Chernozem of similarthickness and exhibiting intensive cryoturbation (the latterpaleosol yielded the 14C date). The lower soil is betterdeveloped than the upper soil (Chalchula et al., 1997). Theupper soil may have developed through the silty parentmaterial and welded to the lower Chernozem during a pe-riod of low dust input and climatic amelioration.

At Kurtak, the best-developed soil during the last inter-glacial period is a Chernozem, located at a depth of about20 m (Fig. 3). Underlying this soil is a bed of loess and aBrunisol, with the paleosol perhaps marking the onset of thelast interglacial period. Chalchula (1995) and Chalchula etal. (1997) show that Brunisols in the Kurtak area are asso-ciated with a parkland-forest environment. The Chernozemrepresents a change to a more continental climate with anincrease in summer temperature similar to the present-dayclimate and soils.

Sections in the Chinese Loess Plateau

In the Loess Plateau, soil development increases south-ward in response to a warmer and wetter climate. In con-trast, at Yulin no soils are evident during the last glacialperiod (Fig. 4). Here, an increase in the loess accumulationrate, near the cooler and drier desert, occurred at the ex-pense of soil development. The result is time-equivalentloess sedimentation equal to two OIS-3 soils present atYangchang (Rokosh et al., in press). At Yanchang, the lastinterglacial soils are the best developed, relative to themodern soil, followed by the lower and upper OIS-3 soils,respectively. The latter two soils developed during intersta-des of the last glacial period, where a slight increase ininsolation in the upper atmosphere is evident relative to theintervening cold periods (Berger and Loutre, 1991). Typi-cally, the chernozem-like soils are associated with a steppeenvironment (Liu, 1985; Rutter and Ding, 1993).

The last interglacial period in the Loess Plateau is rep-resented by a welded pedo complex that exhibits no lessthan three soil-forming periods that have been correlated toOIS 5a, c, and e. The lowest paleosol is generally the bestdeveloped soil, as at Yanchang, although this is not alwaysobserved (Sun et al., 1995). Clay cutans are seen in soils ofthe southern Loess Plateau (Rutter et al., 1991), providingevidence for a forest cover flanking the Qinling Mountains.Closer to the desert source at Yulin the complex consists ofa series of loess and paleosol strata, similar to Kurtak, rather

than the welded pedo complex viewed at Yanchang and inthe southern Loess Plateau.

Correlation of the Russian Plain, Siberian, andChinese loess-paleosol records

Figure 5 shows our correlation of the sites in the RussianPlain, Siberia, and China. For convenience, only the Lih-kvin site from the Russia data and Yanchang from the LoessPlateau are used for this comparison. Loess deposited dur-ing OIS 2 is present in all areas, with the thickest depositsin China and Siberia. At Kurtak and Yanchang, wintertemperatures are dominated by the Siberian High Pressurecell located near Lake Baikal, Russia. This cell may havestrengthened during cold episodes of the last glacial period(Ding et al., 1995). The Russian Plain sites were influencedby proximity to the Fenno-Scandian Ice Sheet. Cryoturba-tion or ice wedges occur in all three sites. The weak soils ofOIS 2 and 4 are the most observable difference between thethree areas. The soils represent a brief change to a warmerand wetter climate that is reminiscent of the interstades ofthe last glacial period seen in Greenland ice cores (Grooteset al., 1993). There is evidence of similar interstades in theChinese records, but these warm periods are not readilyidentified in the field. High-resolution climate proxy vari-ables such as magnetic susceptibility and grain size areneeded to delineate these brief warm periods in the LoessPlateau. The presence of these soils at Kurtak may suggestthat this area, dominantly a subarctic continental regime, isexceptionally sensitive to brief changes in climate. Further-more, for these soils to develop there must be a reduction indust input relative to the rate of soil development. Evi-dently, loess accumulation rates in China were still high,relative to soil development during these short warm peri-ods. In the Russian Plain, the sections are perhaps too thin,relative to the sample interval, to identify millennial-scalewarm periods. In this respect, the presence of lake sedi-ments during the glacial period at Gololobovo may holdpromise for identifying short warm periods in the Russianrecords.

In all three areas, excluding Gololobovo, the last inter-glacial soil is a pedo complex consisting of at least twosoils. Grassland soils dominate the profiles in China, Kur-tak, and Korostylievo, while perhaps a moister and moremaritime climate near Moscow resulted in the developmentof forest soils at Lihkvin and Gololobovo. The Kurtakprofile exhibits no less than five warm periods during thelast interglaciation, rather than the classic three warm peri-ods denoted by OIS 5a, c, and e. This is also seen at Yulin,where the magnetic susceptibility shows at least five peaksin the record reflecting multiple warm periods. The basalsoil during the last interglacial at Kurtak is a Brunisolaccording to our present analysis. Further chronostrati-graphic refinement of the OIS 6/5 transition is needed todetermine if the Brunisol marks the onset of the last inter-

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glacial period, or if the soil identifies the transition asmarked by climatic variability, similar to the OIS 2/1 tran-sition. Either way, the trend to climatic amelioration duringthe stage 6/5 transition, culminating in the warm climatemaximum of isotope stage 5e, was marked by distinct vari-ations in climate in central Siberia.

Conclusion

The three areas that we have examined are quite dif-ferent in geographic setting, loess source, and modernclimate, yet the records of climatic change during the lastinterglacial-glacial cycle are similar. The loess-paleosolstrata in all the records reflect the changing climate of thelast glacial period, albeit at different resolutions. TheChinese records show OIS 3 to comprise both loess bedsand paleosols, reflecting multiple warm and cold periods.In the Siberian and Russian records, OIS 3 shows up asa stacked or welded paleosol that does not have theclimatic resolution of the Chinese data. OIS 2 and 4 inKurtak are significant because they clearly identify aseries of thin and weakly developed paleosols that are notviewed, to the authors’ knowledge, in any other loess-paleosol records in the world. These soils hold promisefor determining the global extent of millennial-scalewarm periods of the last glacial period.

The paleosols of the last interglacial period suggest that

a grassland environment dominated central Siberia, China,and the southern Russian Plain due to the proliferation ofChernozemic-type soils. Forest-type soils are viewed in thesouthern Loess Plateau, flanking the Qinling Mountains,and in our northern Russian Plain sites during this period.The record at Kurtak clearly shows that there were morethan three warm stages during the last interglacial periodand that the OIS 6/5 transition is likely marked by climaticvariability similar to the OIS 2/1 transition.

Acknowledgments

This work was carried out as part of Canada’s climatechange program—Climate Systems History and Dynam-ics—funded by Natural Sciences and Engineering ResearchCouncil, Canada, and Environment Canada. The authorsthank these agencies for their generous support. In addition,the Chinese Academy of Sciences, the Russian Academy ofSciences, and the University of Ziln supported our projectby providing logistical support, laboratory analyses, andscientific advice. N. Catto (Department of Geography, Me-morial University, St. John’s, Newfoundland and Labrador),J.D. Morosova, V.P. Nechaev, V.V. Semenov, and K.G.Dlussky (Geographical Institute, Russian Academy of Sci-ences) are acknowledged for their aid in the description ofmany of the Russian sections.

Fig. 5. Pedostratigraphic correlation from the Russian Plain to Siberia to China. The dashed line indicates that the correlation of the soil of the Kurtak sectionis uncertain. The magnetic susceptibility scale at Kurtak is the reverse of the other sections presented in this paper.

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References

Berger, A., Loutre, M.F., 1991. Insolation values for the climate of the last10 million years. Quaternary Science Reviews 10, 297–317.

Bolikhovskaya, N.S., 1995. Evolution of Loess-Soil Formation of NorthernEurasia. Moscow State Univ. Press, Moscow, [in Russian].

Chichagova, O.A., Cherkinsky, A.E., 1988. Radiocarbon Studies in Geog-raphy. Institute of Geography, Academy of Sciences of the U.S.S.R.,Moscow, [in Russian].

Chlachula, J., 1995. Pleistocene climate history of southern Siberia. Ph.D.thesis. University of Alberta, Edmonton, Alberta, Canada.

Chlachula, J., Rutter, N.W., Evans, M.E., 1997. A late Quaternary loess-paleosol record at Kurtak, southern Siberia. Canadian Journal of EarthSciences 34, 679–686.

Ding, Z., Sun, J., Rutter, N.W., Rokosh, D., Liu, T., 1999. Changes in thesand content of loess deposits along a north to south transect of theChinese Loess Plateau and the implications for desert variations. Qua-ternary Research 52, 56–62 doi:ques.1999.2045.

Ding, Z.L., Liu, T.S., Rutter, N.W., Yu, Z.W., Guo, Z.T., Zhu, R.X., 1995.Ice-volume forcing of East Asian winter monsoon variations in the past800,000 years. Quaternary Research 44, 149–159.

Drozdov, N.I., Cheka, V.P., Laukhin, S.A., Kol’tsova, V.G., Akimova,E.V., Ermolayev, A.E., Leont’ev, V.P., Vasil’ev, S.A., Yamskikh,A.E., Demidenko, G.A., Artem’ev, E.V., Vikulov, A.A., Bokarev,A.A., Foronova, I.V., Sidoras, S.D., 1991. Chronostratigraphy ofpalaeolithic sites of central Siberia (the Yennisey Basin) [in Russian],in: Excursion Guide of the International Symposium on the Chrono-stratigraphy of the Palaeolithic of North, Central and Eastern Asia, andAmerica, 13th INQUA Congress, China, 1991, Siberian Branch, Rus-sian Academy of Sciences, Novosibirsk, Russia.

Fang, X., Li, J., van der Voo, R., 1999. Rock magnetic and grain sizeevidence for intensified Asian atmospheric circulation since 800,000years B.P. related to Tibetan uplift. Earth and Planetary Science Letters165, 129–144.

Geiger, R., Pohl, W., 1954. Revision of the Koppen-Geiger Klimckarte derErde. Erdkunde 8, 58–61.

Grootes, P.M., Stuiver, M., White, J.W.C., Johnsen, S., Jouzel, J., 1993.Comparison of oxygen isotope records from the GISP2 and GRIPGreenland ice cores. Nature 366, 522–554.

Little, E.C., 2002. Sedimentology and stratigraphy for Quaternary depositsof the Russian Plain. Ph.D. thesis. University of Alberta, Edmonton,Alberta, Canada.

Little, E.C., Lian, O.B., Velichko, A.A., Morozova, T.D., Nechaev, V.P.,Dlussky, K.G., Rutter, N.W. (in press). Quaternary stratigraphy andoptical dating of loess from the East European Plain (Russia). Quater-nary Science Reviews.

Liu, J., Liu, T., Chen, T., 1998. Loess dating progress in China. Past GlobalChanges (PAGES) Newsletter 6, 2.

Liu, J., Nie, G., Chen, T., Song, C., Zhu, G., Li, K., Gao, Z., Qiao, Y.,1995. A preliminary high resolution time scale for the last 130,000years at Weinan loess section. Sciencia Geologica Sinica (OverseasEdition; Supplementary Issue) 1, 9–22.

Liu, T.S., 1985. Loess and the Environment. China Ocean Press, Beijing.Martinson, D.G., Pisias, N.G., Hays, J.D., Imbrie, J., Moore, T.C.J., Shack-

leton, N.J., 1987. Age dating and the orbital theory of the ice ages;development of a high-resolution 0 to 300,000-year chronostratigraphy.Quaternary Research 27, 1–29.

Morozova, T.D., 1981. Development of Soil Cover of Europe in LatePleistocene. Nauka Press, Moscow, [in Russian].

Morozova, T.D., Nechaev, V.P., 1997. The Valdai Periglacial Zone as anArea of cryogenic Soil Formation. Quaternary International 41/42,57–58.

National Oceanic Atmospheric Administration (NOAA) (1991). Climatesof the World. Historical Climatology Series 6-4. First published 1986,revised 1991. United States Department of Commerce, National Oce-anic Atmospheric Administration, National Environmental SatelliteData and Information Service, National Climatic Data Center,Asheville, N.C.

Rokosh, D., Rutter, N.W., Little, E.C., Ding, Z., and Sun, J. (in press).Lithofacies and pedofacies variations during the last glacial period inthe Loess Plateau, China. Quaternary Science Reviews.

Rutter, N.W., Ding, Z., 1993. Paleoclimates and monsoon variations in-terpreted from micromorphogenic features of the Baoji paleosols,China. Quaternary Science Reviews 12, 853–862.

Rutter, N.W., Ding, Z., Evans, M.E., Liu, T., 1991. Baoji-type pedostrati-graphic section, Loess Plateau, North-central China. Quaternary Sci-ence Reviews 10, 1–22.

Soil Classification Working Group, 1998. The Canadian System of SoilClassification. Agriculture and Agricultural Foods, Canada. Publication1646, Ottawa.

Sudakova, N.G., 1993. Glacial Lithogenesis of Russian Plain. MoscowState Univ. Publishing House, Moscow, [in Russian].

Sun, J., Ding, Z., Liu, T., 1995. The environmental evolution of thedesert-loess transition zone over the last glacial-interglacial cycle, in:Wang, S. (Ed.), Quaternary Geology and Past Environmental Changesin China, Science Press, Beijing, pp. 1–8.

Sun, J., Yin, G., Ding, D., Liu, T., Chen, J., 1998. Thermoluminescencechronology of sand profiles in the Mu Us Desert, China. Palaeogeog-raphy, Palaeoclimatology, Palaeoecology 144, 25–233.

Velichko, A.A., 1990. Loess-paleosol formation on the Russian Plain.Quaternary International 7/8, 103–114.

Velichko, A.A., Dlussky, K.G., Morozova, T.D., Nechaev, V.P., Semenov,V.V., Rutter, N.W., Little, E.C., 2000. The Gololobovo section. Loess-soil-cryogenic formations of Moscow-Oka plain. Paleosols and modernsoils as stages of continuous soil formation. in: Makeev, A.O., Veli-chko, A.A. (Eds.), Abstracts and Field Excursion Guidebook V, Inter-national Symposium on Paleopedology,. Institute of Geography, Rus-sian Academy of Sciences, Moscow, pp. 67–87 [in Russian].

Velichko, A.A., Gribchenko, Yu. N., Gubonina, Z.P., Morozova, T.D.,Nechaev, V.P., Sycheva, S.A., Timireva, S.N., Udartsev, V.P., Khal-cheva, T.A., Tsatskin, A.I., Chikolini, N.I., 1997. Main features ofloess-soil formation, in: Loess-Soil Formation of East-European Plain.Paleogeography and Stratigraphy, Institute of Geography, RussianAcademy of Sciences, Moscow, pp. 5–24. [In Russian].

Velichko, A.A., Nechaev, V.P., 1984. Late Pleistocene in EuropeanUSSSR, in: Velichko, A.A., Wright Jr., H.E., Barnosky, A.D. (Eds.),Late Quaternary Environments of the Soviet Union, Univ. of Minne-sota Press, Minneapolis, pp. 79–86.

Zhang, X., Chen, Z., Zhang, G., Chen, T., Liu, H., 1996. Remote mineralaerosols in Westerlies and their contributions to the Chinese loess.Science in China (Series D) 39, 134–143.

Zhao, S., 1986. Physical Geography of China. Science Press, Beijing, andJ Wiley, New York.

109N.W. Rutter et al. / Quaternary Research 60 (2003) 101–109