Belan -Deoghat Section

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MEMOlfiS GEpLOGICAL SOCIETY OF INDIANo. 32. PP . 282-308

Quaternary Geology and Prehistoric Environments in theSon and Bela Valleys, North Central IndiaM.A.J. WILLIAMS AND M.F. CLARKE!

Mawson Graduate Centre for Environmental Studies. University of Adelaide.Adelaide. South Australia 5005. AustraliaI Fonnerly. School of Earth Sciences. Macquarie University.New South Wales 2109. Australia

AbstractFour widespread alluvial formations ranging in age from Middle Pleistocene to Holocene havebeen identified. described. mapped and partially dated in the Son and Belan valleys of north central'India (covering parts of Madhya Pradesh and Uttar Pradesh). The three oldest formations are cappedby aeolian deposits of very fine sandy clay which appear to be slightly to substantially reworkedloess. These three formations' contain reworked as well as primary-con.text Lower. Middle and .Upper Palaeolithic stone tools. The youngest formation is of Holocene age and contains primarycontext Neolithic artefacts. Beneath the Late Pleistocene Baghor Formation is a buried channel-fill

of volcanic ash which was erupted from Toba volcanic caldera in nonhern Sumatra 75 kyr ago.

IntroductionFor twenty or so years prior to 1980, the late Professor G.R. Sharma and hiscolleagues from Allahabad University had identified and mapped a large number ofLower, Middle and Upper Palaeolithic sites in the Son and Belan valleys of MadhyaPradesh and Uttar Pradesh in north central India (Shaima et al. 1980; Sharma andClark 1983). This pioneering work deserves high praise: the survey area was vast,poorly served by access roads, with large tracts of dense thorn scrub. Some of the moredetailed maps dated from the last century. Air photos were not available and so werenever used. In 1980 systematic excavation of selected Lower, Middle and UpperPalaeolithic sites in the Son valley was initiated by G.R. Sharma in collaboration witha team from Berkeley directed by Ptofessor J. Desmond Clark (Sharma and Clark1983; Kenoyer et al. 1983). Working very closely with the archaeologists, M.A.J.Williams was responsible for describing and sampling a number of key Quaternarystratigraphic sections (Fig. 1) and for attempting to reconstruct the allu vial history ofthe Son and Belan during the 1980 and 1982 field seasons (Williams and Clarke 1984;Clark and Williams 1986, 1990).The following account is distilled from this preliminary and mostly unpublishedfieldwork and from subsequent radiometric dating and sedimentological analyses.


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Sillll 11. ,/ ( _-I- to K......".,~ __ ' - . , . _ ___ I/ ~ ~ I i- - / . I i ~ ~~ ">AmIlia I "- ! 9 ~ -- "(, 4 'Meln Belan ' ,/! : : - . . : , . , . ~ S t d o n ./ - SeotiN 2 , 4 ' 5 ~ .~ ~/' \$ >Deoghat ( ( 5/ ~ ~ . 5km,1-- / . ~ J 82'O!)- - - - -:". ---'-' "-"----'.-.::..'

'II 1882 plllogl." aectiana82"15'

,." Kymero ,\ ~ _'fang ~ ~" ~ " r l ' G4''':1'I'/! ' , {I G4,;",{f)\ Bighor SIte. II --i.'" ,r r,________ " ' - - - - ' ~ K h u n d O r l 1II:::as: to1 " " " r , l ! M u r ~ h l l__ "'._. Nala M " ~ ~ i ' ; t '~ ~ . --- - - - ~ . - - - - - . " . '~ : : . , ; , , ~ , ~ " _ ~ Ie- _ .- iil1' _ - c.mp;; Ge , .. 7 '",3:.ll10""C:>-HAWAI. - -Me",; 'r ', '- Gl.L-., G12', - - ~ ,. - t , ~ " , : : ~ - - s : ; =.s ~ Bighor Bi h , - - ' - - -o. /!"" .... _/, c:.tiar/-

.q;.-;-I}nfi2

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284 M.AJ. WILLIAMS AND M.F. CLARKE

One feature of Indian Palaeolithic archaeology noted at this time by both Jacobson(1975) and Paddayya (1977) was an undue preoccupation with fossil bones and stoneartefacts recovered from alluvial gravels. The theoretical dangers of this approach arefairly evident. Apart from the fact that gravels are not easy to date except in a relativesense, there is no guarantee that the bones and stone tools are of one age, even whenthey appear relatively unabraded. The identification of three gravels (designated I, II,III in ascending stratigraphic order) in both the Belan and Son valleys, associatedrespectively with Lower, Middle and Upper Palaeolithic stone tool assemblages (Sharma1975), was a useful initial working model. Unfortunately, image and reality weresometimes confused, and observations became clouded with circular reasoning. Agravel could be assigned a relative age on the basis of included artefacts; and artefactscould be dated according to whether they belonged to gravel I, IT or Ill.

I t was also very rare to find all three gravels in a single stratigraphic section, andfield inspection of particular gravels soon revealed that they were highly complex, withsubstantial vertical and lateral facies variations, making it increasingly difficult for thestratigrapher to accept that there were only three gravels. Little further progress seemedpossible until the gravel chronology had been replaced by an alluvial stratigraphydefined and dated independently of the archaeology, and based upon accepted tenetsof stratigraphic mapping.

Results of the 1980 Season's Geological ProgrammeThe outcome of the first season's stratigraphic work in the Son valley (Williamsand Royce 1982, 1983) was the recognition of four main alluvial fonnations (Fig. 2)which, for the sake of simplicity, are here called A,B,C and D (for actual fonnationnames see Table 1).

3. Terminal Pleistocenesands and clays

Lower Proterozoicmetasediments 1. Middle Pleistocenegravels and clays

Present-day channelsands and pointbarsof River Son

2. Upper Pleistocene gravels,sands and clays

Fig. 2: River terraces and Quaternary geological fonnations in the middle Son valley, Madhya Pradesh, northcentral India (after Clark and Williams 1986: Fig. 3)


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THE QUATERNARY OF CENTRAL INDIA 285

Table I: Quaternary alluvlll formations in the Sorp valleyI

A. Sihawal FormationMiddle Pleistocene colluvial-alluvial clayeygtavels and fanglomerates with Lower Palaeolithic artefacts.Capped by generally sterile grey and yellow mottled very fine sandy clay of aeolian provenance.B."Patpara Fonnation ,(?)Late Middle to early Upper Pleistocene fluviatile red-brown clayey fine gravels, gravelly clays andgranule sands with "transitional Lower to Middle Palaeolithic artefacts.,C. Baghor Formation'Upper Pleistocene to Early HolQ!:!ene fluviatile pale yellow-brown coarse sands and calcreted gravelsmerging laterally into and/or capped by horizontally-bedded silts and clays. Some Middle Palaeolithicartefacts near base, but mostly Upper Palaeolithic. with surface and near-surface concentrations ofMesolithicand younger material.D. Khetaunhi FormationMiddle to Late Holocene fluviatile fine sands, silts and clays. Neolithic artefacts.Note: Between Formations C and D there are minor remnants of an end-Pleistocene/earliest Holocene dark claywith fresh Upper Palaeolithic b l a d ' e ~ and blade-cores.

The oldest Formation (A) consists of local pediment gravels capped by severalmetres of archaeologically sterile aeolian clay. In and on the gravels are fresh andabraded Lower Palaeolithic bifaces of Late Acheulian aspect.. Disconformably over A is Formation B: an upward-coarsening sequence of reddish-brown gf&velly clays and gravelly sands in which are interstratified Late Acheulianto Middle Palaeolithic artefacts, often quite fresh and sharp. The eroded surface of Bis the base of Formation C.Formation C is perhaps of greatest stratigraphic and archaeological interest. Nearthe main river it consists of two distinct members. The Coarse Lower Member consistsof cross-bedded and planar-bedded sands and gravels which contain Middle to UpperPalaeolithic stone artefacts and an abundant fossil vertebrate fauna. Near the river theCoarse Member is usually capped by horizontally-bedded silts and clays. The distinction between a Coarse Lower Member and a Fine Upper Member is not alwaysabsolute: on occasions sands and clays may be interstratified. Away from the river bothmembers of C merge laterally into massively-bedded aeolian clays.After the deposition of C, the river cut down into its floodplain, which is some30-35: m above the low-water river level and 15-20 m above normal flood level.Formation D represents a minor phase of Holocene aggradation and consists of horizontally-bedded fine sands, silts and clays.

Alluvial History and Quaternary Climates: Initial InterpretationA simple model was proposed by Williams and Royce in February 1980 (Williamsand Royce 1982, 1983) to account for the alluvial stratigraphy of Formation C. Theargument was based upon four main premises:

(a) Indian rivers with densely vegetated catchments tend to be high-sinuosity. suspension-load rivers;(b) Indian rivers with sparsely vegetated catchments tend to be low sinuosity. bed-load rivers;(c) vegetation in north central India would be dense during warm, wet interglacial or postglacial times; and


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286 M.A.J. WILLIAMS AND M.F. CLARKE

(d) vegetation in north central India would be sparse during cold, dry, full g l a ~ a l times.Our 'initial interpretation of the fine upper member of alluvial Formation C wasthat it represented vertical accretion of fine overbank deposits during warm, wet

postglacial times (Terminal Pleistocene to Holocene), in contrast to the Coarse LowerMember. This we attributed to bed-load aggradation (lateral accretion) by a moreseasonal Son during the Last Glacial Maximum (c. 25 kyr B.P. to c. 15 kyr B.P.), whennorthern India was drier and colder than today (Singh et al. 1972, 1974; Singh andAgrawal 1976).

Evidence from Indian Ocean Deep-Sea CoresBefore reviewing the' aims and achievements of the 1982 season's geologicalprogramme, it is helpful to consider the overall pattern of Quaternary climate changethroughout the Subcontinent. The best record of Late Quaternary climatic events inIndia is that provided by the surrounding Indian Ocean (Prell et al. 1980; Cullen 1981;Duplessy 1982). More limited data from on land include the Holocene pollen spectra

of some of the Rajasthan lakes (Singh et al. 1974) and evidence from geomorphic andarchaeological reconnaissance studies in Gujarat and Rajasthan (Allchin et al. 1978),none with adequate time control.Duplessy's (1982) elegant study of glacial to interglacial contrasts in the northernIndian Ocean offers encouraging support to our own attempts at reconstrcting LateQuaternary changes in river flow and sediment load in the Son and Belan valleys ofMadhya Pradesh. He used differences in the planktonic foraminifera that lived in thenorthern Indian Ocean during the Late Pleistocene and Holocene to reconstruct theprobable climates at those times.Towards 18 kyr B.P. the salinity gradient in the Bay of Bengal was very muchsteeper than today, reflecting a drastic reduction in freshwater input from the Gangaand Brahmaputra. This inference is consistent with our suggestion, based on sedimentary evidence, that the Son was a more seasonal river at this time, with a sparselyvegetated catchment.The upwelling that is now a feature of the southern coast of Arabia (and acontributor to aridity inland) had also disappeared at this time, indicating that thesouthwest summer monsoon winds were not particularly strong during the Last GlacialMaximum. A weakened summer monsoon and much reduced summer rainfall wouldaccount for the aridity evident in northwest India during the Last Glacial Maximum(see Goudie et al. 1973 and the thermoluminescence dates of Rajasthan dunes obtainedby Singhvi et al. 1982).In contrast to the weak summer monsoon, the northwest monsoon seems to havebeen stronger during the Last Glacial Maximum. Evidence includes the clockwisecirculation pattern in the Bay of Bengal revealed by a tongue of low salinity water. Thecombined evidence from rivers, lakes, dunes and pollen spectra accords well withDuplessy's reconstruction of a drier, windier climate towards 18 kyr B.P. over muchof India, with less rain in summer and a stronger winter monsoon than today (Williams1985).During the Early Holocene the marine isotopic record indicates a reversal of theLate Pleistocene pattern of weak summer and strong winter winds (Duplessy 1982). By


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15 kyr B.P. the ice had disappeared below 5000 m in the northwest Himalayas (Singhand Agrawal 1976). Early Holocene cold upwelling water accentuated the aridity of thesouth coast of Arabia in response to the stroqger summer winds. The SW monsoonblew vigorously, bringing summer rain to swell the floods and fill the lakes of India.Runoff from the Indus, Ganga and Brahmaputra increased, and the rivers of centralIndia became less seasonal. .. The lakes of Rajasthan began to fill shortly before 10 kyr B.P. With minorfluctuations they remained full and fresh until about 4-3 kyr B.P. after which theybecame saline (Singh 1971; Singh et al. 1972).To sum up, the Early to Middle Holocene climate of India was generally wet andwarm, with heavy monsoonal rain in summer and moderate rain in winter. By about4-3 kyr B.P. the Late Holocene desiccation of northern India was under way, aggravated by the impact of Neolithic herding, land clearance and cultivation. At the presenttime the margins of cultivation are advancing into the hitherto wooded footslopes ofthe Vindhyan hills in the middle Son valley, leading to renewed soil loss and gullyerosion.

The Toba Volcanic Ash in the Son ValleyOne important outcome of the 1980 fieldwork in the Son valley was the jointdiscovery by Williams and Royce on February 5, 1980, of a very pure volcanic ashfilling a buried channel beneath the Lower Member of the Baghor Formation just

below the confluence of the Son and Rehi rivers, on the Son left bank (Williams andRoyce 1982). This ash was erupted from Toba volcanic caldera in Sumatra some 75kyr ago and is discussed in more detail below.The Toba volcanic ash has aroused considerable interest among geologists inrecent years (Acharyya and Basu 1993, 1994; Rampino and Self 1992, 1993; Mishraand Rajaguru 1994; Badam and Rajaguru 1994). Given current interest in the variousToba ash deposits found at an increasing number of localities throughout India, andthe strong possibility that there are at least two chronologically distinct Toba tephrabeds in India, a brief account of its initial discovery in the Son valley in 1980 maybe of interest here. A more detailed description of the ash will appear elsewhere.The ash was first observed by the author and Keith Royce just below the Son-Rehiconfluence on February 5, 1980. Our initial but erroneous impression was of a horizontally-laminated fine sandy dIatomite up to 3.4 m thick and at least 10 m wide.Interstratified within the horizontally-layered ash were lenses up to 45 cm thick ofwhat we at first interpreted as a reworked very fine aeolian sand.The base and eastern margin of the ash deposit were obscured by the talus (lyingat the foot of the cliff) in which the section was exposed. A horizontal layer of gravelup to a metre thick capped part of the upper surface of the ash. This gravel was itselfin part eroded and replaced by a channel-fill of fine to coarse gravel up to 3 m thick,inset into the upper surface of the ash to a depth of 1-2 m.The enigmatic nature and provenance of the so-called "fine sandy diatomite"prompted us to embark on a detailed physical and chemical examination of the fieldsamples after our return to Australia.Microscopic examination of our field samples by D.A. Adamson (MacquarieUniversity) confirmed that the "fine aeolian sands" and "fine sandy diatomites" were


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in fact the glass shards of avolcanic ash.Detailed grain-size analysis by G. McTainsh (Griffith University) revealed that allsamples were similar, with modes lying within the 30-50 J.lIl1 range.Strontium isotope analysis by D. Whitford (CSIRO Division of Mineralogy, Sydney)indicated a 87S rJ86S r ratio for our sample S44 of 0.71504 0.00006, consistent withan origin from Toba volcanic caldera in Sumatra (Whitford 1975).Two years before our 1980 field season in the Son v a l l ~ y , Ninkovich et al. (1978)had described a widespread volcanic ash layer recovered from piston cores taken in thenortheast Indian Ocean and the Bay of Bengal.Tlwy concluded that this ash eruptedfrom the Toba volcano in northern Sumatra some 75 kyr ago. They also noted that thisLate Pleistocene eruption was the largest magnitude explosive eruption recorded for theentire 2 million years of Quaternary time. The map they produced shOwing the distribution ofToba tuffs in Sumatra and the equi valent ash layer in deep-sea cOJ;'e${NJnkovichet al. 1978: Fig. 1) revealed a fan-shaped ash plume radiating out to the northwest andwest-northwest at an angle of about 50. Extrapolation of the deep-sea Ilh)ayer clearlysuggests that every part of India would have received some ash, as is n ~ w becomingmore and more apparent (Acharyya and Basu 1993: Fig. 1): ' , ~ ,

Samples of the Son volcanic ash were also sent to C.A. Chesner (Eastern IllinoisUniversity) who confinned that they belonged to the youngest of the Toba eruptions(Rose and Chesner 1987; Chesner et al. 1991). Current work on this eruption, nowdated to roughly 75 kyr ago, is increasingly focused on its cooling impact on the worldclimate at that time (Rampino and Self 1993). I t is probably no coincidence that theinception of the rapid build-up of the Laurentide Ice Sheet and of a major coolingsignal in the Vostok ice core are also dated to about 75 kyr age (Jouzel et al. 1987;Williams et al. 1993).

Aims of the 1982 Geological ProgrammeIn the Belan valley it was apparent that we n,eeded to examine the status of thethree tool-bearing gravel units identified hitherto. A rapid survey of certain Belanvalley sections at Deoghat, Mahagara, Chillahia and Chopani-Mando in February1980, in the company of D. MandaI and B.B. Misra, revealed both similarities withand contrast to the alluvial sequence mapped by us in the Son valley. It was thus quitepossible that each of the three units designated as gravel I, IT and III was more complexthan suspected, and could well be polygenic.The Ganga alluvium at Sarai Nahar Rai (Shanna 1975) contained Mesolithicartefact assemblages comparable to those at Chopani-Mando in the Belan valley. Apartfrom its potential for Quaternary stratigraphic correlation, this site might allow us todetennine when the Holocene Ganga began to cut down.Shell-bearing silts inspected by us at Kurha in the Ganga valley and at Deoghatin the Belan valley, suggested that it may be possible to establish a partial radiocarbonchronology of Late Quaternary events in these two Valleys. However, isolated shelldates would not in themselves be of much help in reconstructing the pattern of prehistoric environmental changes. Our aim was therefore to detennine accurate stratigraphic histories for each major river valley in this archaeologically-rich sector ofnorth central India.


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Results of the 1982 Season's Geological Programme(a) Alluvial Stratigraphy of the Ganga and Yamuna Rivers at and Above TheirConfluence

Three major sections were logged and sampled for radiocarbon dating (Fig. Sa:sections 1 to 3). Section 1 was at Jhusi, 1 Ian upstream of the Ganga-Yamuna confluence,on the Ganga leftbank. About 22 m of yellow-brown calcareous silts were capped bya protohistoric mound. Pottery from the base of this mound antedates the NorthernBlack Polished ware dating to 600-700 B.C. suggesting that the base of the protohistoricmound may be about 3 kyr old. Yellow-brown silts similar to the Jhusi silts are alsoknown at Kuiha and Sarai Nahar Rai where they contain microliths dating to c.1O kyrB.P. (Sharma 1975). Beneath the Jhusi silts there are at least 5 m of cross-beddedreworked carbonate nodules, with foreset dips of 23_32 and palaeo-current directionsof 35 (NNE).

SYMBOLS USED IN GEOGRAPHICAL SECTlONS

U ..... . JVV 'V - . Ionel boundIIry b I I r - - .congIoIMr".Iherp boundery bu buff~ debrielow "--'1 oWldery " .,.,m. i In .. ... .......:: D UncI . . . . . . .' . . . 00 bone 0 -....D>: =. and t. 8ItIIId 01 ...

.............. R ....~ ..- - ..... .,. W .....~ ., W ..,... Y ,.....

'M . ........ (III' .........rn IDMI FL ........ LB .......K radio ....... RB .....8IuI,[ ] dIIUIIed 1n1C1D.,. ., , .......... 1.2.3.* ....... . nIndu~ - . . , .__ " a i t

Fig. 3b: Symbols used in geological sections


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Section 2 was on the Ganga left bank roughly 1 km upstream of the Sringaverpuraarchaeological site. The horizontal silts and silty bands exposed in the banks could betraced in continuous outcrop for at least a kilometre above and below the ancient city,the tank of which dates to the first centur.y A.D. (La] 1981; Lal and Dikshit 1978-79).The January 6, 1982 river level was 82.90 m AMSL; normal flood level at theSringaverpura gauge is 87.98 m, and the maximum level attained by the 1978 floodswas 88.68 m. There are thus at least ten metres of alluvium above the present floodlevel. It seems probable, therefore, that the Holocene Ganga has entrenched roughly10 m into its end-Pleistocene or Early Holocene floodplain. Such entrenchment isclearly not related to a fall in sea level, since the sea was rising steadily until about6-7 kyr B.P. when it reached its present level.Section 3 on the Yamuna right bank at Telauli village 2-3 km downstream of Mau,in Banda District, has interesting.parallels with Ganga section 2. Both sections appearto belong to an upward-coarsening alluvial sequence, with massive horizontal beds ofsand in the upper part of the section resting conformably over horizontally-beddedclays and loams. Present flood level in the Yamuna reaches within 4 m of the top ofthe logged section, but there is a further 4-5 m thickness of eroded depositstratigraphically above the top of section 3, again indicating some 4-10 m of incisioninto the Late Pleistocene or Early Holocene floodplain. A shell-bed at +14.8 m abovethe January 10, 1982 river level was sampled for radiocarbon dating. Its 1"C age of15,540170 B.P. (Beta-4788) thus allows us to specify a minimum age for finalaggradation and a maximum age for river downcutting. All shell samples were testedby X-ray diffraction for possible recrystallisation from aragonite to calcite.Preliminary field identifications (for which we are indebted to Mark Kenoyer ofBerkeley) suggest that there are at least five species of mollusc within the shell-bed:

Parreyssia favidens (Benson): a small freshwater musselLamellidens marginalis (Lamarck): a large freshwater unionidlndoplanorbis exustus (Deshoyes): a small gastropod characteristic of terrestrialand swampy habitatsDigoniostoma cerameopoma (Benson): a gastropod characteristic of swampy andterrestrial habitatsViviparus bengalensis (Lamarck): characteristic of ponds and run-on sites.

(b) Alluvial Stratigraphy of the Belan River between Chopani-Mando and AmiliaEight major sections in the middle Belan valley were described and sampled indetail, and five others were sampled specifically for radiocarbon dating but were notlogged in detail because they seemed to be lateral variants of sections already described. Simplified logs are given in Figures 4 and 5.At Mahagara (section 4, Fig. 4) the uppermost gravel unit contains shells dated

to 10,030 115 B.P. (SUA-142). All shells were from the lower 40 cm of the crossbedded gravels which form a bed up to 115 cm thick.Banked against the main section, with its surface 3.80 m lower than the top of,section 4, is a Neolithic midden (Mahagara Index Trench) of grey-brown (10 YR 313) gritty loam with lenses of rolled, poorly-sorted carbonate gravel, interbedded withbroken potsherds. A perforated mussel shell in the north wall of the Index Trench was


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BELAN RIVER : GEOLOGICAL SECTIONS 100:[ RBARB ~ O r O ~ 200m upl t rum 500m downstream201- ~ ~ ~ 4 b RB LB10K. _ , ~ : t 3 5 b ~ ~ , .18 I- I I ! I ~ ~ >-16 I- . ~:- 8 b .:- !14 I- ~ 4 t'"3 b 6 b t'"...12 I- >5 ~rIl

10 f-- 4 b3 b CIaI- I 0 2B b ' A ~, : gap 5 !OJD .....?-.: v 4 Rb (' l81- I 0 3 30 2 2 Rb41- I 0 2Ab 0 = 2 b :;,21- kD .. 1 b1 b iii':" 1 1w.. .. w.. OL- ...... bank, cliff

4 MAHAGARA 5 CHILLAHIA 8 DEOGHAT BRIDGE 7

Fig. 4: Quaternary stratigraphic sections, Belan river


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"'"'f>. BElAN RIVER (abMdoned chann'l) : CHOPANI MANDOm - down - channel I4'-ChInneI -4 't LB13 LB12 LB11 II. 2 b ~5 b rn ~10 l - I : : ~ I ~ . : . . t l ~ : 5 b 0c::e ~ ~ .-=- >..l 4 b tl .. 4 b8 l - LB 1:-:- 1 Vb . . 73 ..~ ~ >"~ I ....."l I ~ : : : : 0 02 f- [ ' ~ l go IJ: ..."I ' : o 01 l - ~ ..... . 1bIdroc:k" . 00 L '--.J LJ ..

Unit, cliff ........800m .......... 8m 200m bank. cllfSA 8B Be e

NFig, 5: Quaternary stratigraphic sections, Belan river, Chopani Mando


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of interest in that similarly perforated mussel shells are used today forskinning greenmangoes (B.B. Misra: personal communication, 16.1.82). It is highly probable that theIndex Trench deposit accumulated rapidly, for there is no significant difference at onestandard deviation between any of tht" four charcoal radiocarbon dates, despite the factthat the deepest and shallowest samples are up to 2.35 m apart vertically (see Table2) .Table 2: Radiocarbon dates from Mahagara Index Trench, Belan valley (data from Sharma et al. 1980: 199-200)Sample, Lab. No.PRL-409PRL-408PRL-407BAIIAu/ALLDIMGR-77-1

Age Depth below datum1400 150 B.C. -1.15 m1330 120 B.C. -1.25 to -1.35 m1440 100 B.C. -2.4 to -2.6 m1480 110 B.C. -2.8 to -3.5 m

From these dates we can draw the following conclusions:(i ) Until 10,030 B.P. or shortly thereafter the Belan and its tributaries were actively aggrading their floodplain.(ii) Between about 10,030 B.P. and 3,430 B.P. (1480 B.C.) the Belan had cut down at least 7.3 m (3.5 +3.8 m) into its Pleistocene floodplain.

Beneath the 10,030 B.P. shell-bearing rolled carbonate gravels there are 12 m ofbrown (5 YR 4/4 to 7.5 YR 3/4) massive clay loams and fine sandy clays with up to20% irregular pedogenic carbonate nodules - the probable source of the rolled gravelsin the gravels capping this section. The absence of cut-and-fill structures, the lack ofany obvious strtigraphic breaks, and the gradational nature of any colour or grain-sizechanges in the Mahagara brown clay loam prompted the inference that we weredealing with a loess. A sample collected from +16 m gave a thermoluminescence ageof 29,900 ' 4500 (Alpha-897), indicating a Late Pleistocene age for this unit.Stratigraphically beneath the Mahagara brown clay loam was a bench of sandstonegravel and gravelly sand at least 8 m thick. Banked up against both gravel and clayloam was a recent terrace of very fine alluvial sand, the surface of which was' up to11.2 m above the January 12, 1982 river level. The sequence of events at Mahagarawas as follows:

(i ) Deposition of fluviatile gravels to +8 m(ii) Loess deposition (primary or secondary) to +19 m(iii) Pedogenesis during and after (ii)(iv) Local erosion of loess, concentration and redeposition of carbonate nodules towards \0 kyr B.P.(v) River incision of at least 7 m between 10 kyr B.P. and 3400 B.P.(vi) Deposition of recent sandy alluvial bench to +11 m(vii) Continued incision.

The "Epi-Palaeolithic" assemblage (Upper Palaeolithic blades, non-geometricmicroliths) recovered by excavation of the 10 kyr B.P. gravels is broadly similar to theassemblage in archaeological layer 10 at Chopani-Mando (Sharma et al. 1980:143;B.B. Misra: personal communication, 12.1.82), as well as to that seen eroding fromthe uppermost beds of section 5 at Chillahia (Fig. 4).


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Chillahia section 5 (Fig. 4) was again on the Belan right bank, about 3 kmupstream. The Belan flows westwards so that Chillahia lies east of Mahagara.The basal 2.5 m ohhe section consist of a brown (7.5 YR 4/4) clay loam with upto 50% calcium carbonate. Not seen by us, but rumetimes exposed by drought is anunderlying conglomerate from which V.D. Misra and B.B. Misra collected one cleaverand a biface on June 22, 1971.Above the brown clay loam are three gravel units with a total thickness of 4.4 m.The lower and upper two units form resistant benches of horizontally-bedded sandstoneor quartzire pebbles in a matrix of silica and iron hydroxide. The middle unit displayslarge-scale trough crossbeds. Foreset dips of 10-20 show variable flow directionsbetween 120 and 260, consistent with the 250 palaeocurrent direction inferred fromimbrication. The flow of the modern Belan at this site is to the southwest.From the lower gravel unit have come Middle Palaeolithic quartzite tools andbifaces (B.B. Misra: personal communication, 14.1.82). The assemblage seems broadlycomparable to that excavated from the Patpara Formation ("FormationB", Table 1)in the Son valley during 1980. From the middle cross-bedded unit have come over 200artefacts, mostly of Middle Palaeolithic aspect, with fewer fashioned from quartzite andfar more of chert. Artefacts in the upper gravel unit were entirely of Middle Palaeolithicaspect, with abundant chert scrapers and no bifaces. What time gaps are representedby the erosional contacts between the three gravel units we cannot gauge.Above the gravels is a massive unit of brown (7.5 YR 4/4-4/6) calcareous very finesandy clay to clay loam similar in colour and texture to the Mahagara loessic unit insection 4. The basal 5.75 m of the clay loam is capped by a 1.3 m thick bench of rolledcarbonate gravel with minor clasts of shale and sandstone and occasional recrystallisedmussel shells. Above this intraformational gravel the brown clay loam continues fora further 8.70 m, bringing the total thickness of the loess formation to 15.75 m.Eroding from the upper few metres of the loess is a non-geometric microlithic assemblage, in which the dominant raw ~ a t e r i a l is chalcedony with subsidiary black chert.From section 4 and 5 (Fig. 4) it is evident that deposition of the calcareous brownloess was accompanied by carbonate segregation within the profile, and was interrupted by minor phases of erosion and reworking of pedogenic carbonate derived fromthe loess. The resulting intraformational gravels appear to be local phenomena and soshouid not be given the status of regional lithostratigraphic markers. There is no validreason why any of the six gravel units exposed in (and below) section 5 should bereferred to as Gravel I, II or III, unless the numerical suffix refers specifically to thelocal stratigraphic section.Section 6 and 7 are respectively 200 m upstream and 500 m downstream of theDeoghat bridge, with 6 on the right bank and 7 on the left bank (Fig. 4).At the base of section 6 there are at least two metres of rolled sandstone andcarbonate gravels which are capped by three metres of brown (7.5 YR 4/6 and 5/6) clayloam and a further 2.25 m of sandstone pebbles, fining upwards to fine gravel.Stratigraphically above the gravel (which may be a local channel-fill deposit) andespecially well exposed 200 m above the bridge, is a brown loess-like very fine sandyclay loam, the vertical face of which is distinctively fluted by rainwash rills. Withinthe deposit, which is over 12 m thick, is an intraformational lens of fine carbonategravel stringers (Fig. 4). .

Section 7 comprises two distinct fine-grained formations separated by a widespread shell-bearing gravel unit 85 cm thick dated at 18,055 150 B.P. (Beta-4789).


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296 M.A..J. WILLIAMS AND M.F. CLARKE

The lower formation, a reddish-brown (5 YR 4/8) sandy loam with 3% black pisolites,is largely obscured by talus, and may overlie the conglomerate bench which crops outa water level. A thin band of ironstone pisolites, .sandstone fragments and bits ofbroken shell in a reddish-brown sandy clay matrix htrms a minor gravel unit 25-30 cmthick near the top of this formation, which here comprises a further 65 cm of darkreddish-brown (5 YR 3/5) sandy clay.The shelly gravel unit sitting on the eroded surface of the red-brown sandy clayvaries lithologically over quite short horizontal distances. At the site of section 7, thegravel consists of ironstone pisolites and ferruginous sandstone fragments in a brownclay loam matrix. Fifty metres upstream it becomes an indurated bed of rolled carbonate nodules with crude planar bedding. The most common shells within the gravel aretwo species of freshwater mussel similar to th,ose found in the Belan today. These shellswere sampled at section 7, as well as at 7B (in gully 150-200 m upstream and inlandfrom 7), and 7C near Amilia, 2-3 kIn downstream. In all three places the shelly gravelhad an abrupt erosional contact with the underlying red-brown clay.Above the shelly gravel bed at section 7 there are 11 m of alternating dark andlight brown (7.5 YR 4/3-4/4) calcareous light clays, often with a strong subangularblocky structure. The uniformity of colour, texture (grain size) and structure in theupper 11 m, the lack of shells, and the absence of fluviatile gravels again suggest thatthe parent material of the stratified soils and sediments above the shelly gravel was acalcareous wind-blown dust or loess. Since it is now technically possible to obtainfairly reliable thermoluminescence dates from loess and other aeolian sediments (Wintle1981; Wintle and Huntley 1982; Singhvi et al. 1982) we have sampled every Belansection with this possibility in mind. We hope to be able to test the accuracy of theTL dates against the radiocarbon ages obtained on unrecrystallised shell samples. BothTL and additional 14(: dating programmes are in progress now.Shells were also collected from gully section 7D near Koldihwa archaeological siteon the high terrace opposite Mahagara (section 4). The shells were from a carbonategravel at least 5 m higher in elevation than the 10 kyr B.P. gravel of section 4. Theywere thought to be laterally equivalent to a gravel band at the base of the Koldihwaexcavation which has yielded Upper Palaeolithic blades and a 14(: age of either c.25kyr B.P. or 19 kyr B.P. (Sharma et al. 1980: 71; B.B. Misra: personal communication,15.1.82). The actual 14C age for the shells was 25,430 350 B.P. (Beta-4877).Our final investigations in the Belan valley were focused upon four sections on thesouth bank of a cut-off channel of the Belan opposite Chopani-Mando archaeologicalsite (Fig. 5, sections 8A,B,C and 9). We also revisited the Belan Main section (Fig.4, in Williams and Royce 1982) on the Belan right bank just downstream of thebifurcation of the Belan and its cutoff channel. The latter is functional during flood,and re-enters the main Belan just upstream of section 4 at Mahagara.At section 8A the cutoff channel is a bedrock channel cut in horizontal quartzosesandstones of Upper Vindhyan age (=Upper Proterozoic). At 3.2 m above the exposedbedrock, and probably sitting directly on bedrock which is here obscured by talus, isa resistant conglomerate bench of flaggy sandstone and gravelly sand which hasyielded Middle Palaeolithic quartzite flakes, scrapers and discoid cores.Roughly a hundred metres upstream, at section 8B, bedrock crops out from thecutoff-channel water level to +6:5 m. Above bedrock is a 2.65 m thick unit of paleyellow-brown (10 YR 6/4) clay loam overlain by 3.8 m of dark brown (10 YR 3/4) lightclay from which Upper Palaeolithic chert blades have been collected (B.B. Misra:


16/27


personal communication, 16.1.82).The lowest stratigraphic unit in section 8C, 80 m further east, is laterally equivalent to the lowest unit in 8B, and overlies a thin lag gravel said to contain MiddlePalaeolithic quartzite flakes. Its upper surface is the Bca horizon of a now truncatedpalaeosol which developed within the yellow-brown clay loam during a pause indeposition. Above the eroded palaeosol there is a metre of dark brown light clayequivalent to unit 2 of section 8B. It too has yielded Upper Palaeolithic and earlyMesolithic artefacts. Capping the brown clay is a brown (10 YR 4/4) fine sandy clayloam at least 3 m thick, the surface of which is being actively eroded. This unitcontains microliths but no pottery.Perhaps the most complete of the Chopani-Mando sections is step trench 9 (Fig.5). Above a 2 m thick conglomerate bench of platy sandstone and nodular calcrete isa yellow-brown (10 YR 4.5/4) calcareous clay loam overlain by a brown (10 YR 4/4)clay loam from which have come Middle Palaeolithic quartzite and chert blades. Abovethe brown clay loam is a brown (7.5 YR 4/3) fine sandy clay unit some 3 m thick withUpper Palaeolithic blades and microliths. Capping the section is an eroded brown (10YR 4/4) clay laom unit at least 0.8 m thick, also with microliths.One feature common to all of the Belan sections studied by us is a brown toyellow-brown clay loam to fine sandy clay formation which predates the 10 kyr B.P.shelly gravel at section 4 and appears to be a slightly reworked Late Pleistocene loess,the bulk of which accumulated during the Last Glacial Maximum, on the evidence ofour shell dates and of the two shell dates of 23,840 B.C. (PRL 86) and 17,765 B.C.(TF 1245) available from the shelly gravels which immediately underlie this formationat Deoghat and Koldihwa (Sharma et ai. 1980: 71; B.B. Misra: personal communication, 15.1.82).Our present interpretation of this formation differs slightly from that of Mujumdarand Rajaguru (1970) who thought that "the possibility of these finer soils beingdeposited solely by wind was very meagre" (Mujumdar and Rajaguru 1970: 102) andconsidered them to be overbank deposits or fluvio-Iacustrine deposits associated witha floodplain environment. The operative word is "solely". We consider the parentmaterial to be loess, reworked to a minor degree by slopewash and local runoff. Someof the more highly stratified beds may well be overbank deposits laid down by a loesschoked Late Pleistocene palaeo-Belan. Until we have completed our dating,micromorphological and granulometric studies, further speculation seems unprofitable.Table 3: Provisional lithostratigraphic sequence in the middle Belan valley, based on fieldwork in January1982 and February 1980I. Tabular sandstone conglomerate over Upper Vindhyan sandstone bedrock. Lower Palaeolithic cleaversand bifaces. Age probably Middle Pleistocene.2. Calcareous brown clay loam. Archaeologically sterile. (?)Middle Pleistocene.3. Planar and cross-bedded sandstone gravels. Middle Palaeolithic artefacts. (?)Late Middle to (?)early

Upper Pleistocene.4. Reddish-brown sandy clays and clay loams. (?)Upper Pleistocene. Archaeological associations not known.5. Shell-bearing gravel(s), mostly rolled carbonate nodules and black ironstone pisolites. Upper Palaeolithicartefacts. Upper Pleistocene (c.25 kyr to 19 kyr B.P.).6. Brown and yellow-brown calcareous clay loam and sandy clays. Minor intraformational gravels, mainlyrolled carbonate nodules. Upper Palaeolithic to Epi-Palaeolithic and (?)Mesolithic artefacts. Age lateUpper Pleistocene (c.25 to c.1O kyr B.P.)7. Holocene clays, loams and fine alluvial sands. Mesolithic, Neolithic and protohistoric artefacts.

14*


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298

o1'-30- ..J .eocI -120

M.A.J. WILLIAMS AND M.F. CLARKE

- 1 . ~ ~ ~ - - ~ - - ~ - - ~ - - ~ - - ~ - - ~ ~ ~ ~ ~ - - ~ - - ~ - - ~ ~o 20 40 10 100 120 140 1. 110 200 220 240 210Age(1P)

Fig. 6: Sea level curve for the past 260,000 years (after Aharon and Chappell 1986: Fig. 4.5)

The red-brown clay loam to fine sandy clay exposed in the Belan Main section andin sections 7 and 7b may well be a weathered loess. In colour and soil texture it issimilar to the finer units of the Patpara Fonnation (Fonnation B) in the Son valley.The results from our dating programme may resolve this issue which for the presentis best left open.Major stratigraphic units and their associated archaeological occurrences aresummarised in Table 3.I f units 2, 4 and 6 were originally laid down as wind-blown dust, then they wouldpresumably reflect times when the prevailing climate was drier and windier than today.Duplessy's (1982) reconstruction of the last glacial climate in India is consistent withour suggested later Pleistocene age and loessic origin for unit 6 in Table 3.Given that times of low seal level were times of maximum ice volume, andaccepting the equation of loess deposition with glacial (or stadial) aridity, the curve ofsea level changes over the past 260 kyr (Fig. 6) suggests possible ages for units 2 and4, assuming they are of aeolian provenance.Unit 2 could date to roughly 160 10 kyr B.P. and Unit 4 could date to 70 kyrB.P. or earlier. However, the shape of the curve indicates a progressive trend towardsfull glacial conditions, and there seems no good reason why wind-blown dust could nothave accumulated in the Belan valley throughout much of the long interval betweensuccessive interglacials. The present climate in north central India is probably onlyrepresentative of, at most, 10% of the preceding 120 kyr, so that throughout much ofthe Middle and Upper Palaeolithic conditions may have been significantly colder, drierand windier than they are today.

(c) Alluvial Stratigraphy of the Middle Son Valley Between Byawaharkhand Villageand Jogadha Bridge

Our first priority in the Son valley was to relate the archaeological excavations atBaghor I,ll and III to the local and regional geological history (see Fig. 7 and 8).Section G 1 is 1 krn west of Baghor I and G2 is in the same Nala as G I, but about350 m upstream. The main unit in both sections is a yellow-brown loess, the fieldtexture of which is a calcareous very fine sandy clay to heavy clay loam. Colours rangefrom 10 YR 5/6 near the exposed base of G 1 (which has up to 20% red-brown mottles)through 10 YR 5/4 to 10 YR 4/4 (brown) near the top of G2, i.e. from yellow brownto brown. All colours are moist colours and particular care was taken in describing


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m987654321o

2 Yb

1 Yb

G1

SON VALLEY : GEOLOGICAL SECTIONS

A.

GF

in the, vicinity of Baghor excavations

G2

4 b3 gb

2 Yb

1C1B1A Yb

.=11 2 Rb1 b

G3Fig. 7: Quaternary stratigraphic sections, Son valley near Bagbor

...I: )~i!>-...l"!I5 Rb ~. ~ " ' 1 4 i!>-

3 qp ill:!>


19/27


field colour and texture of all deposits, since even quite subtle differences proved.diagnostic. Within the loess there are minor intraformational lenses of shale rubble(mostly debris flows) and rolled carbonate gravels.Conformably above the loess at G2 there is a vertisolic dark grey-brown (l0 YR3/2) sandy clay. Above the dark clay is a thin band of shale gravel with agate andchalcedony flakes and microliths. The microlithic horizon is partly concealed beneatha layer of red-brown sandy clay loam (see also section G3, 0.5 km east of G2) whichsometimes contains Neolithic implements.Exposed beneath the yellow-brown loess at G2 there are three gravel units. Theserange from shale fragments in 'a clay matrix (lA) to quartzite conglomerates withcrude fluviatile bedding (lB, 1C). In the bed of the seasonal stream which is exhumingthese gravels we found one large quartzite core (c.25 x 25 x 20 cm) and one largequartzite flake, possibly Lower Palaeolithic.

Fanglomerates also crop out 0.1-0.2 km northwest of Baghor I, at section G4 (Fig.7). The site is closer to the shale quartzite escarpment, and the gravels differ fromthose at G2 in being matrix-supported. Units 1A and 1C have a characteristic debrisflow fabric. Interstratified within the debris flows there are several beds and lenses ofred-brown (5 YR 5/6) sandy clay and sandy clay loam, often with a strongly pedalstructure quite unlike the massive structure of the yellow-brown loess at Gland G2.Erosion of this material, which is reminiscent of the Patpara (or Formation B) claysstudied in 1980, has provided the matrix material of the debris flows. We consider thatthese scarp-foot clays represent an eroded and weathered loess which predates theyounger yellow-brown loess which is so widespread in this region.We sampled and described the three archaeological test trenches at Baghor I, IIand III (Figs. 8 and 9), and an additional geological section (G5) as a further checkupon 'Baghor III. It soon became clear that the'mottled grey-brown sandy clay/clayloam unit at the base of Baghor I and II and comprising almost all of Baghor III wasstratigraphically equivalent to the upper metre or two of the yellow-brown loess at G2.The dark vertisolic clay (bed 3) at Baghor II is a lateral counterpart of the darkvertisolic clay at G2 (bed 3). The red-brown ("orange" when dry) sandy clay loam atBaghor II (bed, 2) is the same horizon as the top bed at G3 and G4 (Fig, 7). Indescending order, the stratigraphic sequence is as follows:

(i) red-brown ("orange") sandy clay loam with Neolithic artefacts(ii) brown clay loam(iii) grey-brown sandy clay with Mesolithic artefacts(iv) debris flows (shale rubble)(v) very dark grey-brown vertisolic clay(vi) grey-brown mottled clay loam/sandy clay with Upper Palaeolithic artefacts grading downwards into(vii) brown loess (clay loam/sandy clay) greyer upwards, yellow-brown down profile; minor intraformationalshale and carbonate lenses(viii) interbedded red-brown clays (weathered older loess?) and sandstone/shale debris flows in red-brownclay matrix(ix) water-laid sandstone cobbles and gravels: large core and flake, possibly Upper Palaeolithic, (Note thatthese gravels could be a lateral equivalent of viii, but we think this is unlikely given the absence ofinterstitial red-brown clay)

Our subsequent work in the Son was designed to answer two important questionswhich had now arisen:


20/27

~ -BAGHORlTE8TTRENCH

IOUIhflcl

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2 m

, , ' . '.' 1 ' M I I I v y ~ ~

2....--.S / .... . - . . ; r ~ t 1 1gracIIng downward, ID

griIly brown qndy claywIItI....w F. &Mn nodulnlA Urk grey-brown undy clay ...1()1j6 F. &Mn nodule, S

foooooooooooooooooooooooooopoooo 0I ,o 1m ~

~ = ~ g r i I t y 4 lrIfactight clay-loam~ fine . I e 811M! i'I M NnUpOrtbind of clay ("" , . , ,1) S ,."ple for .n.lyail

10001 ~ " l r i ' I e e r1A Ih.Irp bound8ry. grldetionll' bouncSwy .. on.1 bound8ty

Fig. 8: Baghor I and n test trench sections, Son valley

IS b n M n ~5 ~ f I n t undy dllyWllhIOIIhIc III'II1CtI& NndItone INIrtUpOItI

.. ' ............ ... __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. _ .. ... _ .. _ ....... ....... .

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...


21/27

SON VALLEY : GEOLOGICAL SECTIONS

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in the vicinity of Baghor eXC8YationI

6 ':11 3 ' ~ 4 Ab-- I - - gb+b -- 3 gb-- 2 I:. 2 - l' gb -- 1 b+Rb-- --00m

BAGHORIII OSFig. 9: Quaternary stratigraphic sections, Son valley, Khunderi Nala

Khunderi Hala right bank

e b7B b mA b 4A bb 4B = 3 ..Vb 2 -"

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22/27

THE QUATERNARY OF CJj:NTRAL INDIA 303

(i) What is the relationship- between the piedmont stratigraphic sequence evident around the Baghorexcavations and the alluvial stratigraphic sequence exposed in the banks and tributary nalas of theSon?

(ii) How many loess fonnations are there, and what is their relationship to artefact-bearing units?

The answers to these two related questions are illustrated in section G6 to G 12 (seeFigs. 9-11).Above the basal gravel units at G6 and G7 (Fig. 9) there are recent alluvial sandsand laminated clays which belong to the youngest terraces of Khunderi Nala. They arebanked up against the main yellow-brown loess formation which contained shells witha 14C age of 20,135 220 B.P. (Beta-4791).On the south bank of the Son at Nakjhar Khurd we sampled a step-trench located20 m downstream (east) of the 1980 archaeological trench (G9 in Fig. 10). Above theeroded siltstone bedrock were exposed 4.5 m of mottled grey and yellow-brown sandyclay with a thin interbedded debris flow unit (bed 3 of G9). Beds 1 to 5 we interpretas a slightly reworked loess mixed with some fluviatile coarse sand and bedrockderived shale fragments. A sample from near the top of bed 4 has yielded a thermoluminescence age of 103,800 19,800 (Alpha-899). This loess is the Fine Member ofthe Sihawal Formation (Formation A) and in the 1980 step-trench it overlies a discontinuous basal conglomerate - the Sihawal Gravel Member - which contains LowerPalaeolithic bifaces This gravel may be a lateral equivalent of the indurated gravelswhich overlie limestone bedrock in Khunderi Nala north of the Son at sections G6, G7and G 10 (Fig. 9 & 10). In all three sections the gravel is the lowest exposed unit, andunderlies a mottled grey and yellow-brown fine sandy clay.Resting on the eroded surface of the Sihawal Loess Member at Nakjhar Khurd aretwo metres of horizontally-bedded red-brown (7.5 YR 5/6) and brown (10 YR 4/6)coarse sandy clay, the upper 0.55 m of which has a coarse prismatic structure, and maybe part of an eroded palaeosol.Above the "palaeo sol" (unit 6D, Fig. 10 section G9) is a fluviatile gravelly coarsesand, the colour of which ranges from brown (10 YR 4/6) to dark red-brown (5 YR3/3-4). This unit (7) is the base of a channel fill, so that formation and memberthickness can differ by several metres over a lateral distance of 20 m. A further 11.75m of gravelly sands overlie unit 7, so that the level summit of the section is +25 mrelative to its ~ x p o s e d base, which is 1 m above low river level.The stratigraphic status of the red-brown gravelly sands above unit 6D is still indoubt. They could belong in the upper, eroded part of the Patpara Formation or in thesubsequent Baghor Formation. They differ from the Baghor sands in colour and in theabsence of carbonate, and may represent a stratigraphic transition from the red-browngravelly clays and clays of the main Patpara Formation to the unconsolidated paleyellow-brown fluviatile sands and calcreted gravels of the Baghor Coarse Member.Alternatively, the Patpara Formation may consist of a clay-rich facies and channelsand facies, with the latter more common along the axis of the valley, and the formermore extensive on footslopes and palaeo-floodplains.In order to correlate the stratigraphic sequence on either side of the Son we rana traverse from near Rampur archaeological site across the river to Semara Nala onthe south bank (Fig. 11). The oldest formation exposed on both sides of the river inthe form of eroded remnants of red-brown sands and clayey sands is the PatparaFormation, here present in its coarse fluviatile facies.


23/27

SON VALLEY : GEOLOGICAL IECTIONI

1CIutdIri ....._ ~ 1 O u d11

8gb 10 r 1b1M1trla.pr c:.mpdI,5Yb " I ; ; ~ bf7

8r-- ~ ; ~ 8 Nt5

4 ~ : t --j' ... :: .. Ybtt3

2 Ybtb 1H 3NttgOF l:..!...j 1 0 [ OF :::": 1.2Ob

010 011Fig, 10: Quaternary stratigraphic sections, Son valley, Nakjhar Khurd

1km-* r I.....1Oud.

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24/27

./::/:

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THE QUATERNARY OF CENTRAL INDIA

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--


25/27


Overlying the eroded surface of the Pat para Formation are the channel sands ofthe Baghor Formation Coarse Member. These are interstratified with silts and clays onthe north bank, as might be expected in the laterally more distal facies of channelsands. On the south bank the Baghor sands are clean, well-sorted sands with nointerfingering units of overbank clays except near the contact with the overlying FineMember clays. Both the Fine and the Coarse Members grade laterally into the massivebrown to yellow-brown loess described earlier in this report.Three dates allow us to place the Baghor Formation Fine and Coarse Members andassociated loess firmly in the Late Pleistocene. A 1"C age of 11,870 120 B.P. (Beta-4793), is in very good agreement with the 1L date for the stratigraphically equivalentunit 50 m further north (Fig. 11).There are sporadic relatively fresh Middle Palaeolithic flakes near the base of theBaghor sands, and Upper Palaeolithic artefacts near the top. The Baghor clays whichoverlie and/or interdigitate with the Baghor sands also contain Upper Palaeolithicblades and blade-cores. Banked against the Baghor Formation (at Khunjun) or elsesitting on the 15 m erosional terrace at the foot of the main 35 m surface (at Rampur)is a brown clay in which there are very well preserved Upper Palaeolithic blades andblade-cores.Using the information discussed above (see Fig. 7-11) we are now in a positionto summarise what is still preserved of the Quaternary history of the middle Son valley.

(i) Bedrock erosion and pedirnentation of Lower Vindhyan metasediments (limestones, shales, cherts,sandstones), probably during the Middle Pleistocene. Deposition of debris flow rubble and alluvial fangravels and clayey gravels with some reworking by the palaeo-Son near present low r i v e r ~ l e v e l . LowerPalaeolithic flakes, cores and bifaces of quartzose sandstone and quartzites on and in these SihawalFormation gravels.(ii) Deposition of fine sandy clay loess during and after accumulation of Sihawal Formation gravels; i.e.,a Sihawal Fine Member and a Sihawal Coarse Member, (?)Middle Pleistocene.(iii) Erosion followed by deposition of Patpara Formation gravelly clays and fluviatile sands. Upper Acheulianto Middle Palaeolithic artefacts interstratified among both fine and coarse facies of the Patpar Formation. Syn-depositional and/or post-depositional reddening of clays and sands. Middle to Upper Pleis- .tocene.(iv) Erosion followed by deposition of Baghor Formation channel sands, overbank clays and yellow-brownloess. Middle to Upper Palaeolithic. Upper Pleistocene.(v) Several intervals of episodic downcutting, lateral planation and inset terrace formation. Upper Palaeolitbic,Mesolithic and Neolithic. Upper Pleistocene to Holocene.

The most important geological achievement of the 1982 season was the identification, mapping and sampling of a very widespread Upper Pleistocene loess in theBelan and Son valleys. Shell samples collected above, within and beneath this formation have allowed us to date it with a reasonable degree of accuracy as well as enablingus to calibrate some of the thermoluminescence dates so far obtained on samples of thisloess. We are thus able to specify limiting ages for the younger Middle Palaeolithic andUpper Palaeolithic occurrences in this part of India.I f the as yet unfinished 1L dating programme proves successful, we will also beable to obtain a better idea of the timing of the transition from Lower to MiddlePalaeolithic by further dating the Sihawal Fine Member loess.Ultimately, we would hope to be able to correlate the continental loess stratigraphyof north central India with the Quaternary marine stratigraphy obtained from Indian Ocean deep-sea cores as well as with Chinese loess stratigraphy. These are excitingpossibilities.


26/27


AcknowledgementsWe remain indebted to Professor J. Desmond Clark and the late Professor G.R.Sharma for inviting us to participate in their joint archaeological investigations, as alsoto our cotIeagues from Allahabad and Berkeley. Our grateful thanks go also to theSmithsonian Institution for air fares and per diem funds, to Allahabad University forarranging transport and accomodation in the field, and to Macquarie University forspecial leave, and research funds for the XRD, 14C and sedimentological analyses.We offer this essay as a tribute to our friend, colleague and erstwhile field companion, Dr.S.N. Rajaguru. More than any other single person, he has worked to placeIndian Quaternary geology on a modern footing through his careful and unflagging

field research throughout the Subcontinent. M.AJ. Williams will long remember thejoy and privilege of working with Raja in the Rajasthan desert in 1983.

ReferencesAcharyya, S.K. and P.K. Basu 1993. Toba Ash on the Indian Subcontinent and Its Implications for Correlation

of Late Pleistocene Alluvium, Quaternary Research 40: 10-19.Acharyya, S.K. and P.K. Basu 1994. Reply to Comments by S. Mishra and S.N. Rajaguru and by G.L. Badam

and S.N. Rajaguru on "Toba Ash on the Indian Subcontinent and Its Implications for Correlationof Late Pleistocene Alluvium", Quaternary Research 41: 400-402.

Aharon, P. and J. Chappell 1986. Oxygen Isotopes, Sea Level Changes and the Temperature History of a CoralReef Environment in New Guinea Over the Last Years, Palaeogeography PalaeoclimatologyPalaeoecology 56: 337-79.Allchin, B., A. Goudie and K.T.M. Hegde 1978. The Prehistory and Palaeogeography of the Great IndianDesert. New York: Academic Press.

Dadam, G.L. and S.N. Rajaguru 1994. Comment on "Toba Ash on the Indian Subcontinent and Its Implications for Correlation of Late Pleistocene Alluvium", Quaternary Research 40: 398-399.

Chesner, e.A., W.1. Rose, A. Deino, R. Drake and J.A. Westgate 1991. Eruptive History of Earth's LargestQuaternary Caldera (Toba Indonesia) Clarified, Geology 19: 200-203.Clark J.D. and M.AJ. Williams 1986. Palaeoenvironments and Prehistory in North Central India: a Preliminary Report, in Studies in the Archaeology of India and Pakistan (1. Jacobson Ed.), pp. 19-41.New Delhi: Oxford-IBH.

Clark, J.D. and M.AJ. Williams 1990. Prehistoric Ecology, Resource Strategies and Culture Chang! in theSon Valley, Northern Madhya Pradesh, Central India, Man and Environment 15(1): 13-24.Cullen, J.L. 1981. Micro-Fossil Evidence of Changing Salinity Patterns in the Bay of Bengal Over the Last20,000 Years, Palaeogeography Palaeoclimatology Palaeoecology 35: 315-356.Duplessy, J.e. 1982. Glacial to Interglacial Contrasts in the Northern Indian Ocean, Nature 295: 494-498.

Goudie, A.S., B. Allchin and K.T.M. Hegde 1973. The Former Extensions of the Great Indian Sand Desert,Geographical Journal 134: 243-257.Jacobson, J. 1975. Early Stone Age Sites in Eastern Malwa, Proceedings of the American PhilosophicalSociety 119: 280-297.Jouzel, J., e. Lorius, J.R. Petit, e. Genthon, N.I. Barkov, V.M. KotJyacov and V.M. Petrov 1987. Vostok Ice

Core: a Continuous Isotope Temperature Record Over the Last Climatic Cycle (160, 000 years),Nature 329: 403-408.Kenoyer, J.M., J.D. Clark, J.N. Pal and G.R. Sharma 1983. An Upper Palaeolithic Shrine in India, Antiquity57: 88-94.Lal, B.B. 1981. Two Indian Epics Vis-A-Vis Archaeology, Antiquity 55: 27-34.Lal, B.B. and K.N. Dikshit 1978-79. Sringaverapura: a Key-Site for the Protohistory and Early History of theCentral Ganga Valley, Puratattva 10: 1-7.Mishra, S. and S.N. Rajaguru 1994. Comment on "Toba Ash on the Indian Subcontinent and Its Implication

for Correlation of Late Pleistocene Alluvium", Quaternary Research 40: 396-397.Mujumdar, G.G. and S.N. Rajaguru 1970. Investigations of the Pleistocene Sediments from the Belan Valley,U.P., Indian Antiquary 4: 96-105.


27/27


Ninkovich, D., N.J. Shackleton, A.A. Abdel-Monem, J.D. Obradovich and G. lzett 1978. K-Ar Age of the LatePleistocene Eruption of Toba, North Sumatra, Nature 276: 574-577.Paddayya, K. 1977. New Research Designs an51 Field Techniques in the Palaeolithic Archaeology of India,World Archaeology 10: 94-109. .Prell, W.L., W.H. Hutson, D.F. Williams, A.W.H. Be, K. Geitzenauer and B. Molfino 1980. Surface Circulation of the Indian Ocean During the Last Glacial Maximum, Approximately 18 000 Yr. B.P.,Quaternary Research 14: 309-336.Rampino, M.R. and S. Self 1992. Volcanic Winter and Accelemted Glaciation Following the Toba Super-Eruption, Nature 59: 50-52. 'Rampino, M.R. and S. Self 1993. Climate-Volcanism Feed Back and the Toba Eruption of -74000 YearsAgo, Quaternary Research 40: 269-280.Rose, W.l. and C.A. Chesner 1987. Dispersal of Ash in the Great Toba Eruption, 75 Ka, Geology 15: 913-917.Sharma G.R. 1975. Seasonal Migrations and Mesolithic Lake Cultures of the Ganga Valley, in K.C.Chattopadhyaya Memorial Volume (G.R. Sharma Ed.), pp. 1-20. Allahabad: Allahabad University,Sharma G.R. and J.D. Clark 1983, Palaeoenvironments and Prehistory in the Middle Son Valley. Allahabad:Abinash Prakashan,Sharma G.R., V.D, Misra, D. Mandal, B.B. Misra and J,N. Pal 1980. Beginnings ofAgriculture. Allahabad:Abinash Prakashan.Singh, G. 1971. The Indus Valley Culture Seen in the Context of Post-Glacial Climatic and Ecological Studiesin North-West India, Archaeology and Physical Anthropology in Oceania 6: 177-189.Singh G. and D.P. Agrawal 1976. Radiocarbon Evidence for Deglaciation in North-Western Himalaya, India,Nature 260: 232.Singh G., R.D. Joshi and A.B. Singh 1972. Stratigraphic and Radiocarbon Evidence for the Age and Development of Three Salt Lake Deposits in Rajasthan, India, Quaternary Research 2: 496-505.Singh, G., R.D. Joshi, S.K. Chopra and A.B. Singh 1974. Late Quaternary History of Vegetation and Climate

of the Rajasthan Desert, India, Philosophical Transactions of the Royal Society of London B267:467-501.Singhvi, A.K., Y.P. Sharma and D.P. Agrawal 1982. Thermoluminescence Dating of Sand Dunes in Rajasthan,India, Nature 295: 313-315.Whitford, 0 J. 1975. Stronium Isotopic Studies of the Volcanic Rocks ofthe Sunda Arc, Indonesia, and theirPevogenetic Implications, Geochimica et Cosmochimica Acta 39: 1287;p02.Williams, M.AJ. 1985. Pleistocene Aridity in Tropical Africa, Australia and India, in Environmental Change

and Tropical Geomorphology (I . Douglas and T. Spencer Eds.), pp, 219-233. London: GeorgeAllen and Unwin.Williams, M.AJ. and M.F. Clarke 1984, Late Quaternary Environments in North Central India, Nature 308:633-635,Williams, M.AJ. and K. Royce 1982. Quaternary Geology of the Middle Son Valley, North Central India:Implications for Prehistoric Archaeology, Paleogeography Palaeoclimatology Palaeocology 38:139-162.Williams, M.AJ. and K. Royce 1983. Alluvial History of the Middle Son Valley, North Central India, inPalaeoenvironments and Prehistory in the Middle Son Valley (G.R. Sharma and J.D. Clark Eds.),pp. 9-23. Allahabad: Abinash Prakashan.Williams, M.AJ., D.L, Dunkerley, P. De Deckker, A.P. Kershaw and T. Stokes 1993. Quaternary Environ-ments. London: Edward Arnold. t

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