Late Quaternary Environmental Change in the Pravara River Basin, Northwestern Deccan Upland, India. N.Sadakata, H.Maemoku, S.N.Rajaguru, Sheila Misra and K.Fujiwara

Reprinted from "Proceedings of The International Symposium on Paleoenvironmen tal Change in Tropical-Subtropical Monsoon Asia"

Special Publication No.24, pp. 43-56, March 1995

Research Center for Regional Geography Hiroshima University 1-2-3, Kngamiyama, Higashi-Hiroshima, 739,Japan

Late Quaternary Environmental Change in the Pravara River Basin, Northwestern Deccan Upland, India Noboru Sadakata Faculty of Education, Hokkaido University of Education, Hakodate, Japan

Hideaki Maemoku Faculty of Education, Yamaguchi University, Yamaguchi, Japan

S.N. Rajaguru Postgraduate and Research Institute, Deccan College, Pune, India

Sheila Mishra Postgraduate and Research Institute, Deccan College,Pune, India

Kenzo Fujiwara Department of Geography, Hiroshima University, Higashi-Hiroshima, Japan The environmental change in the Pravata river basin located at the northwestem fringe of the Deccan upland was refined from the geomorphological and chrono-stratigraphical points of view. The sediments of colluvial slopes in the upper reaches and thick alluvial fills along the main stream reflect the monsoonal environmental fluctuation between arid and semi arid in the late pleistocene. Three distinct episodes of alluvial fills with coarse grained materials correlated to the arid climate were recognized in the late 40kyrs: 40-25kyr, 19-16kyr and 10-13kyr . Some of the underlying alluvial soils were tentatively correlated to the humid interstadal in the late Pleistocene. The so-called black soil was formed under the humid condition in the early Holocene.

Introduction The Godavari and Krishna river basins of Northwestern Deccan Upland, are one of the best studied regions for Quaternary Palaeo-climate in India Corvinus ( 198I), Rajaguru and Badarn(1984), Rajaguru and Kale ( 1985), Rajaguru and Korisettar( l987), Fujiwara( l990), Rajaguru, Kale and Badam (1993) are some of the recent syntheses of this work. Mishra (in press) has discussed and reviewed the last 50 years of work at the classic Quaternary site of Nevasa. This work has shown that the fluvial systems in the region have fluctuated between aggradational and erosional modes, a number of times in the Quaternary period. During periods of aridity fluvial systems were dominantly in the aggradational mode, while in periods of global humidity soils formed on alluvium, along with erosion of alluvium. In this work, we have refined the subdivisions of the Late Quaternary period on the previously accumulated data and found a good correlation to the global palaeo-climatic record as known from the Oxygen Isotope ratios in deep sea cores (Van C a m p et al., 1982). Whereas, previous works had distinguished Holocene, Late Pleistocene and Earlier than Late Pleistocene units (Corvinusl981, Mishra et al. 1988), a review of available radiocarbon dates from the area (see Table 1) shows that the gravel units within the Late Pleistocene alluvium belong to the most arid phases of this period. At both Nevasa and Sangamner gravels with microliths date to 12.8 kyr. Dates of 10.0 from Asla, in the Krishna basin, 10.3 from Ghargaon in the Mula basin and 11.7 from Inamgaon in the Ghod basin probably date to the same aggradational episode. This dry

episode may correlate to the Younger Dryas event which dates to 10-11 kyr (Peteet 1994). At Nevasa a second gravel with blade tools dates to 16.4 kyr,while at Inamgaon there are two dates of 19 and 21 kyr for gravel with Upper Palaeolithic blade tools. This aggradational episode might be correlated to the Last Glacial Maximum. Some gravel units associated with blade tools, (Sangamner 24.6 kyr, Dharangaon 28 kyr) date to > 25 kyr and probably belong to an earlier arid episode younger than 40 kyr. The age of soils developed on alluvium can be constrained by overlying archaeological material. The youngest soil is overlain by the earliest agricultural settlements dating to about 3.5 kyr. At Chandoli and Nevasa, in addition to this early Holocene soil, an earlier soil developed on silty alluvium is overlain by gravels containing blade tools. At Kalas also a soil developed on silty alluvium is seen overlain by gravel containing blade tools. At Nevasa shells in the gravel date to 16.4kyr. Table 1 Recent Radio Carbon Ages of the Gravel Units in the Northwestern Deccan

Site name

Lab. number

Archaological association

River basin

Dharangaon

BS 662

Microliths

Godavari

Asla

TF1173

Krishna

Gargaon

TFllll

Mula

Inamgaon

BS146

Microliths

Ghod

Inamgaon

TF1177

microliths

Ghod

Inamgaon

TF1003

microliths

Ghod

Nevasa

BS517

microliths

Pravara

Nevasa

BS575

microliths

Pravara

Sangamner

B S78

microliths

Pravara

Sangamner

FRL470

microliths

Pravara

Geographic Setting The Pravara river originates in the Western Ghats at 190301N,and flows 236 km eastwards to the confluence of the Godavari river east of Nevasa (Fig. 1). The altitude of the river source is 1,468 m above sea level. The average channel slope of the Pravara river is 4.2/1,000, which is sufficiently steep for the movement of gravel. From the source, for the first 20 km the river flows in the high relief Western Ghats, which rise 800 m above sea level. In this zone, the tributary streams form colluvial or pediment-like slopes. The Pravara valley, in the rest of it's course flows in a large, gently undulating erosional surface, and the tributary streams transport very little coarse material. It

1s only the Mula river, which joins the Pravara just upstream of N e v a a which supplies coarser material to the mainstream. The main streams are lnclsed 10 to 15 m into the former flood plam on 1% hlch

an agnculturally rlch black sod has developed, which 1s presently intensely cultivated.

The distr~but~on of the annual ra~nlallalong 19"N shows that the heavy ranfall of more than 3,000 mm in the Western Ghats rapldly decreases eastwards (Fig.2, Takahashi, 1994). For instance, at Akola, located just 30 km east of the Western Ghats, the rainfall dramatically decreases to 596 mm. The southwestern monsoon here gwes a hlgh precipitation from July t o September. The d~schargeof the Pravara nver as an allochthonous nver 1s malnly dependent on the high rainfall In the Western Ghats.

Fig. 1 Location of the study area

JUN

lL,,-,-

.-c2. 0 ' !!

JUL

mrn

72%

73

74

75

76

77

78

79

longitude

Ag.2 Distribution of the annual rainfall along 19"N

80

Physiographic and Stratigraphical Description of Four Study Locations Quaternary sediments are found along the slopes of the residual hills, towards the divides in the upper reaches of the Pravara basin, and along the main stream. The first category of deposits are colluvial in nature, while the second are alluvial. Three chronological divisions can be made in the Quaternary deposits based on relative dating (Mshra, Ksirsagar and Rajagurul988), the Holocene (U), Late Pleistocene (Ll) and Older Pleistocene (L2) units. Detailed field observations were made at four localities and are described here. Quaternary Colluvial Sediments in Chandanapuri The Chandanapuri stream, is a southerly ephemeral stream which drains a small area near Sangamner. It is bordered by basalt hills up to 100 m high. Landforms are classified as colluvial slope I, colluvial slope 11, pediment-like slope, and gully (Fig.3) The colluvial slope I under the steep hillslope has a thick mantle of 5 to 20 meters sediment. The surface is covered with an immature brown soil. The colluvial slope 11,occupying a large area of the region, is an extension of the colluvial slope I, but has a sediment cover of only a few meter sand a thick mature black soil cover. Bstinct pediment-like slopes without sediment are seen just below the steep slopes of the residual basalt hills.

Pediment Slope

Colluvial I

colluvial II

Gully

Fig.3 Geomorphological map of Chandanapuri valley -

46

-

Predominantlyephemeral channel Processes-with lenses of gravel (rubbly),roess like silt etc.

Chandanapuri Point.1 r m

Weak calcretisation at various levels

_I

Reddish Cross Bedded Gravel ( "basalt" from dugout material) Boulder Bed (Debris flow?) Petrocalcic Horizon (hard pan calcrete) 30 to 40 cm thick Weathered Bedrock (Murrum) Bedrock

Chandanapuri Point.3

1;

Chandanapuri Point.4 (Pleistocene terrace)

calcreted sand and grave

Fig.4 Cross sections and subsurface materials in Chandanapwi valley (Locations are shown in Fig.3)

One of the conspicuous landform features in this valley plain is gullying. The depth of the gullies is over 10 meters in places. The surface of colluvial slope I especially is severely dissected by many gullies. The depth of the gullys decreases towards the Pravara river. Exposures of the sediments were studied at four points ranging from the valley head to 11 km downstream and are shown in Fig 4. along with the cross sections. At every point, thick colluvial deposits lie on the basalt base. A well section at Mordara, close to the head of the Chandanapuri nala exposed a massive (20 cm thick) valley floor hard pan type calcrete underlying the entire Quaternary colluvial sequence. It overlies weathered basaltic bedrock. The gravel overlying this massive calcrete, contains a few patinated basalt flakes, which indicate an earlier Pleistocene age for the basal deposits. Boulders of this massive calcrete were noticed in basal gravels of the entire Chandanapuri drainage, showing the former extent of this hard pan calcrete. Quaternary Alluvial Sediments a) Kalas

At Kalas, two units of gravellsilt and soil are exposed on the left bank of the Pravara (Fig.5). The upper gravel varies laterally in thickness and pebble size, from a pebbly gravel about 2 m thick to a coarse sand, 30 cm thick. The continuity of the gravel can however be traced. This gravel contains an Upper Palaeolithic industry along with mollusk shells. This gravel covers a 1 m thick black soil developed on calcareous silt, which overlies in turn a second gravel. The gravel containing Upper Palaeolithic artefacts is overlain by a thick yellowish silt which has a thin soil (20 cm) at the surface.

Kalas

m

black soil with crucks

uniform yellowish silt (10YR414)

including calcareous nodule laminated coarse sand sand with gravel (shell fragment) buried brown soil with crucks silt

F i g 5 Profiles of subsurface materials in Kalas

I 1 I

river bed

b) Daimabad -\ This study location is in a meandering part of the middle reach of the Pravara river. The cross section is shown in Fig. 6. A chalcolithic habitational mound is found at this site. The habitational

mound covers black soil developed on Pleistocene alluvium. The black soil has a sharp contact with the underlying yellowish silt belonging to unit LI. However, X ray diffraction analysis shows no difference between the clay minerals of the black soil and the yellowish silt (Fig.7). The clay fraction of both materials consists of smectite components. Many calcareous nodules and tubes are developed in the yellowish silt. Inset to the late Pleistocene strath terrace, is a Holocene fill terrace. This Holocene fill may be quite young, as a terracotta net sinker was found in it. This type of net sinker, has been in use from the chalcolithic period to the present.

Daimabad habitatation mound Pleistocene terrace

,I1

[

earthen net sin

Fig.6 Cross section and subsurface materials at Daimabad

c) Nevasa Nevasa is near the confluence of the Pravara river with the Godavari, and downstream of thc confluence of the Mula and Pravara rivers. The Mula river appears to be the source of most of the sediment seen at Nevasa, as very little sedimentary cover is seen upstream of the Mula confluence. The section seen on the left side of the Pravara at Nevasa is shown in Fig. 8. The uppermost

1.00K-

l m of the cliff comprises a habitational mound of historical period.

The

remaining

sediments belonging to unit

CPS 0.5

LI,are divided into upper and lower parts. The upper part (9 m thick) is mainly composed of silty materials with a few

I

3.00

5.00

10.00

intervening lenticular patches of sand and graved. A prominent

Fig.7 X ray diffraction of the black soil and yellw silt

15.00

Nevasa historical habitat deposit

.//,,,/ ///,.-, .. ///#/// /////#/

////#// ///////

p.gF.5

,-.>%..8& # ,./,.

uniform sitly clay sand and gravel

#//#///,

///////, //f##/#, /

/////.

/$I,,/,.

5K$W ///////.

##////

$f+i:t$

silt with garavel lense

Holocene terrace

a little calcareous nodule

+xg<: .vw..*) calcreterd gravel j'ifiini crucked buried brown soil /3/###..-,

xxx;;

ncluding calcareous nodul river bed - - - c - -

Fig.8Cross section and subsurface materials at Nevasa

gravel patch is recognized 4m below the surface. It is around 1 m thick and continues for a distance of 15 m. Calcrete nodules are seen in the lower part of the upper part of the section. The lower 6m of the section is composed of compact clayey silt with many calcareous nodules. Opposite to this site 15m thick section is seen below the Chalcolithic habitational mound of Nevasa. Below the habitational mound a 40cm thick black soil was underlain, with well developed fissures developed on sandy alluvial silt. The cross section of the Pravara river at Nevasa is shown in Fig. 8. The width of the valley plain is about 550 m. The river bed is about 15 m lower than the surrounding terrace. The southern half of the valley is occupied by an inset fill terrace with a height of 8 m. The sediments of this terrace m

Khalga

Lakshmi Nala rn

buried soil with crucks

calcreted layer sand and gravel with Ascheullan artefact

sand and gravel sand and gravel with Asheulian artefact

Fig.9Subsurface materials at Lakshminala and Khalga, upstream of Nevasa

are composed of fresh sandy materials, with pottery pieces of historical age, placing it in unit U (Holocene). Upstream of Nevasa, the small nala on the north bank, Laxminala, exposes Earlier (LII) and Late Quaternary deposits (LI) (Fig.9). Unit LI comprises a sandy pebbly gravel which yielded Upper Palaeolithic tools and shell, and sandy silt. The LI unit covers a 1.5 m thick black soil developed on LII. The age of the shells from the gravel bed of unit LI is estimated as 18,640+750-690 (Maemoku, 1993). The LII is made up of cross bedded pebbly gravels, which are differentially cemented. The upper part of LII has a horizon of mud balls reflecting the effect of flash floods. The mud -ball horizon has yielded a number of Acheulian artefacts Cement from the lower part of this gravel was dated by Th230lU234 method to >350 ka (Atkinson et al 1990,Kale 1990, Mishra 1992). The third locality at Nevasa is around the Chirki nala, a right bank tributary of the Pravara, downstream of Nevasa town. The Chirki nala exposes Middle Pleistocene gravel containing a rich early Acheulian industry studied by Corvinus (1983). Opposite the Chirlu nala there is an exposure of gravel contaming microliths. Shells from this gravel have been tentatively dated to 10.8 kyr by Maemoku.

Discussion Quaternary Colluvial Sediments The varied litho-facies of thick sediments in Chandanapuri valley show that there were many types of deposition due to running water, debris flow, and sheet floods. Many angular and sub-angular gravel beds common to this valley seem to have been caused by debris flow. Silty material between coarser sediments may be derived from sheet floods and the over bank deposits of the small ephemeral channels. These features suggest that the colluvial slopes in this area were formed under a fairly arid climate. However, there were certain time gaps as indicated by lenses of parhally pedogenised darkbrown soil-sediment within LI and LII. The colluvial sediments are the thickest in the middle reaches of the valley, and they become thin towards the Pravara river. This phenomenon indicates that the colluvial process was very active in the valley pediment, while it was of minor importance near the Pravara river proper. Geomorphic processes under relatively wet climate of Chandanapuri valley are characterized by linear erosion, such as gullying. In this region such erosion occurred after the gravels of unit LI, deposited before the Upper Palaeolithic period, as an Upper Palaeolithic blade was found on it's surface. There is no major unconformity detected within the thick colluvium. This means that the present gullying is one of the most significant geomorphic processes operating during the Holocene. Quaternary Alluvial Sediments Alluvial sediments along the Pravara river at Kalas,Daimabad and Nevasa are,textually quite

different from those of the Chandanapuri valley. Stratigraphically, the sediments are divided into

three units: LII, LI, and U and are correlated with the Lower Pravara Beds, Upper Pravara Beds, and Holocene beds of Corvinus (1983). At Kalas, the LI and LII units are similar, and each comprise a gravel/silt/soil sequence. The LII pre-dates the Late Pleistocene, provably, Upper Palaeolithic. At Nevasa, the LI gravel overlies a soil horizon developed on a silt interbedding with gravel containing Acheulian artefacts dated to > 350 kyr. The LII exposed at different localities belongs to different periods of Pleistocene aridity. Available radiocarbon dates, while still limited in number, suggest a correlation to the Last Glacial Maximum (18 kyr) and the Younger Dryas climatic reversal (llkyr). While the periods of alluviation, appear to be arid, as seen in the presence of mud balls, transported calcrete nodules,and local source of sediment, the soils developed on the alluvium belong to periods of relatively wet climate, on stable parts of the flood plain. The soil units identified on LI and LII (on LII covered by mid-Holocene chalcolithic occupation) are important records of relatively wet periods. Buried soils are dark brown clayey silt with marked development of desiccation cracks. Theyare accretionary vertisols. Thickness of these soils varies between 20 to 150 cm and is thicker where the parent alluvium is clayey. The Holocene inset terrace (U) unit here has previously been correlated to the mid-Holocene period of global aridity, which postdates the Chalcolithic occupation in the region. The presence of the net sinker in this unit at mmabad, might show a more recent date for some of these units, and some of them are part of the present day flood deposits of the Pravara. Environmental Change in Response to the Southwest Monsoon Fluctuation Based on the above discussion, the tentative chronology of environmental change in the Pravara river basin is summarized as follows: (Fig. 10, Table 2) Middle Pleistocene During the Mddle Pleistocene (Phase 1 on Table 2) episodic deposition of sediments, both

gravels and silts, interrupted by small scale deepening, occurred in sedimentary basins along river. This episodic aggradation over most of the Pleistocene reflects the fluctuations in climate between aridity and semi-aridity. This unit represents multiple episodes of aggradation, interrupted by erosion and soil formation, but dating methods available at present are not capable of resolving the events. The most important date the >350 kyr Th/U date from cement in the gravel at h x m i nala (Atkinson et al 1990), which shows that some of the units date to the Early Mddle Pleistocene. Early Acheulian artefacts are found in these Early Mddle Pleistocene units. The units underlying the Late Pleistocene gravels at Kalas, and Chand oli probably belong to later part of the Mddle Pleistocene.

Late Pleistocene Available radiocarbon dates on shells from gravels containing microlithic artefacts suggest that they fall into two discrete phases, one dating between 16-21 kyr (Phase 3 in Table2) and the

Table 2 Phase of Paleoclimatic Change in the Pravara River Basin Phase

Sedimentary units and facies

Dominant Geomorphic Activity

1.middle Pleistocene Aggradation (~3.50kyr to 125 kyr)

4ccumulastion of Colluvial a w e s t Unit(LI1) ;ediments close to the drainage divides M y Acheulian artifacts from Chilki 3ravel units at Laxmi nala and md a g g h t i o n of fluvial sediments md Laxmi dated to >350 3hirki,some of the colluvial units n the flood plain. Current d i n g cyr.(Atkinson et a1.1990) n Chanhapuri nala, Lowest unit nethods are not able to resolve 3t Kalas and Chandri. lifferent aggradational episodes

2.Oxygen Isotope stage Erosionlsoil formation

This soil is correlated to Oxygen [sotope stage 3 on the basis of Soil development on silty alluvium Erosion of alluvium/colluvium and werlying gravel dated to LGM. In I S present at Chandri,Kalas and soil formation on silty alluvium some cases, eg Nevasa, the soil may Nevasa. jate to an earlier humid episode.

C dates on shells from the gravels

14

3.Last glacial Maximum Aggradation

Gravels at Kalas, Chandri and Nevasa

AggI-acfation of alluvium accumulation of colluvium

4.Trminal Pleistocene Aggradation

Gravels at Nevasa, Inamgaon, Gargaon and Asla.

14C dates on shells from the gravel Sheet gravels present in the teminal between 10-13 kyr. Some of the phase of late Pleistocene aggradation gravels have microliths associated.

5.Early Holocene soil formation

Habitation mounds of Chalcolithic Soils developed on silty alluvium Erosion of Alluviumlcolluvium and period dating to 3.5 kyr cover this at Jonve, DaimabdNevasa and formation of soil on silty alluvium soil at the sites mentioned Apegaon

..-

6. Late Holocene Upper Unit(U) alluviation sand and silt

and

between 16-21 kyr associated with microliths

Formation of inset fill terrace, gully Pottery from Chalcolithic period onwards found in this unit erosion

m 204

habitationmound

colluvial I1

Fig. 10 Synoptic model of subsurface materials along the Pravara river

otherfrom 10- 13 kyr (Phase 4 in Table 2). Two dates(Dharangaon and Sangamner) might belong to an earlier episode of gravel deposition (not shown in Table 2). The older of these phases coincides fairly well with the Last Glacial Maximum at 18kyr while the younger phase, although not well resolved, is close to the Younger Dryas climatic reversal dating to about 1 lkyr. Soils developed on silty alluvium are earlier than the overlying sediments. At Nevasa, Kalas and Chandoli, the LGM gravel overlies a soil. At Nevasa, this soil has developed on Middle Pleistocene alluvium and so might be considerably older than the covering sediment, but at Kalas and Chandoli this soil can be tentatively correlated to Oxygen Isotope stage 3, a humid interstadial of the Late Pleistocene. These soils are placed in Phase 2 in Table 2. Holocene As the Holocene started, the southwest monsoon was rapidly strengthened. Under the fairly heavy rainfall conditions the Pleistocene alluvium was weathered into black soil. This soil is covered by Chalcolithic habitational mounds at Jonve, b m a b a d and Nevasa in the Pravara valley. Contemporaneously, the flood plain along the main stream was deeply entrenched. In the latest period gullying started to develop on the valley plains and other slopes. This gullying seems to have been one of the main landform changes in this region during the Holocene. Human impacts such as deforestation and the development of agriculture may be one of the main causes for severe gullying.

Concluding Remarks 1. Thick colluvial deposits are distributed very extensively in the upper reaches of the Pravara river. Mobilization of weathered hillslope material was possible when protective vegetational cover was reduced when the climate was arid. Lack of sufficient discharge ensured that this material was not transported very far. 2. The alluvial fills seen along the river courses were likewise deposited during periods of aridity

as seen in the presence of mud balls, angular calcrete pebbles, calcretized root sand wood (Corvinus 1971). The alluvial soils developed during humid episodes. These episodes occurred during interstadial and interglacial periods ( l , 3 , 5). 3. Available radiocarbon dates on shells from gravels containing microliths suggest that there are three distinct episodes of alluvial filling in the last 40 kyr. The earliest episode occurred sometime between 40-25 kyr. A second episode dates from 19- 16 kyr which correlates fairly well with the

LGM. A final episode of gravel belongs to loTM 13 kyr, in the terminal phase of the Pleistocene and may correspond to the Younger Dryas event for which evidence of global impact has recently been suggested (Peteet 1994). 4. The fill terraces in the entrenched valley along the main stream were formed not only during the arid episode around 3,000 years ago, as pointed out in previous studies, but also during the late Holocene.

Acknowlegements The authors appreciate Prof. V.N. Misra, Director of Deccan College who assisted our project andDr. Masahim Yahata, Geological Survey of Hokkaido, Sapporo who conducted XRD analysis for our study.

References Atkinson, T.C., Rowe, P. J., Powar, N. J. and Kale, V. S . (1990). Report submitted to the Natural Environmental Research Council (U.K.). ms. Corvinus, C.A.(1971). Pleistocene fossil wood from Clurki on Pravara. Current Anthropology 12, 283. Corvinus, G. (1981). ' T h e Pravara river system Vol. 1: the stratigraphy and geomorphology of the Pravara river system." Archaeologica Ventoria Institute fur Ugeschchte, Tiibingen. Corvinus, G.(1983)."The Pravara river system Vol 2: The excavations of the Acheulian site of Chirki on Pravara, India." Archaeologica Ventoria Institute fur Ugeschichte, Tiibingen. Kale,V.S.(1990). Time-scale of landscape ckvelopment in the Deccan Plateau. Tmpicul Geomophology Naosletter 10, 4-5. Fujiwara, K.(1980).Environmental change in the tropical Asia-Study trend and perspective-. Fujiwara, K. ed, t!Ehvironmental Change in Monsoon Asia", The Research Unit and Source Unit for Regional Geography, University of Hiroshima, Special Publication,No.20,1-63. Mishra, S . (in press). Chronology of the Indian Stone Age: impact or recent relative and absolute hting. paper to be presented in the World archaeological congress,Dec 4- 11,1994, Delhi. Mishra, S. and Rajaguru, S.N. (in press). "Progress in chronology and Stone Age Cultures in Western India: a Geoarchaeological Perspective." Mshra, S. (in press). Prehistoric and Quaternary Studes at Nevasx the Last 40 Years. Rajaguru Felicitation Volume Mishra, S. (1992). The age of the Acheulian in India. Current Anthropology 33,325-328. Mishra, S., Ksirsagar, A,, and Rajaguru, S .N.(1988). Relative diting of the Quaternary record from upland Western Maharashtra, in "National Seminar on Recent Quaternary studies in Inda " &l.P.Patel and N. Desai, Eds.) M.S. UniversityBaroda.. Kajale, M.D., Badam, G.L. and Rajaguru,S .N. (1976). Late Quaternary hlstoq of the Ghod valley, Maharashtra. Geophytology 6(l), 122-132. Kale, V.S. and Rajagum, S.N. (1987). Late Quaternary alluvial history of the North ~ e s t e kDeccan ~ upland

region. Nature 325 ,612-614. Peteet, D. (1 994). "Global Younger Dryas?". Special issue, Quaternary Science Reviews l2(5) ,277-355. Rajaguru, S .N., Badam, G.L. (1984). 'Zitho and biostratigraphy of Quaternary formations, Central Godavari Valley, Maharashtra." in 1976 Proceedngs of Symposium on Deccan Tmp and Bauxite. Geological Survey of India misc. Publications 14,89-96. Rajaguru, S.N. and Kale, V.S .(1985). Changes in fluvial regime of Western Maharashtra upland rivers during Late Quaternary. Journal of Geological Society of India 26(1), 16-27. Rajagurh, S.N. and Korisettar, R.(1987). Quaternary Geomorphc Environment and Cultural Succession in Western India. Indian Journal of Earth Sciences 4 (34)349-361. Van Campo,E., Duplessy,J.C. and Rossignol-Stick, M. (1982). Climatic condtions deduced from a 150,000 yr B.P. oxygen isotope pollen record from the Arabian sea. Nature(London) 296, 56-59.