Kapthurin Formation of Kenya, Full-Scale Block Excavation, with Some 52-M2 Surface Which Preserves a Welldated Sequence Ofacheulian Excavated in 2001

WAMEAKUMA

The Kaptlrnrin Formation The Kapthurin Formation is exposed west of Middle Pleistocene shes from Lake Baringo, Kenya, and forms the Middle the 'southern" Kapthurin Pleistoctneportionofthe~mHillssequence(see Formation of Kenya Hill 2002 and refirences therein). Hominid remains have been rccovcftd from sediments bracketed by Christian A. Tryon the Pumice Tuffmcmbcr(K2) and the 'Grcy Tuff;' University of Connecticut now dated by the 'OArPAr method to between 509 Department of Anthropology 9 ka and 543 f 4 ka @em and McBrearty 2002; BOX U-2176 Wood 1999). Archaeological sites arc aUriile Storrs, Connecticut, 06269, USA the Acheulian, MSA and possibly Sangoan and E-mail: [email protected] Faunsrmth.* TheseoccurwithintheMiddleSihsand Gravels member (K3) and tbc overlying Bddcd Tuff member (K4), the latter a complex of tufibous de positsandintercalatcdscdiment(Tal1m 1976,1978, Introduction Cornelissen et al. 1990; McBrearty et d. 1996; McBrearty 1999; Tryon and McBrearty 2002~). Fossil and genetic evidence is consistent with Tcphmstxatigraphic correlatim and a sequence of Afiican origin for sapiens during Mid- an Homo the '"ArPArdates on Wand lava document the tempo- dle Pleistocene (Stringer and An- 1988; Howell ral succession and age of these sites. This work has 1999; McBWand Brooks 2000). One notable demonstrated the complexity of the Acheulien-MSA feature of the Afican Middle Pleistocene archaeo- aansitioq with intmtmtified Achwlian and MSA logical word is the end Of the IMg-livad A&& sites,andshown~thistransitimwithiatheBaringo Industrial Complex and its replacement by diverse basin had by -285 Ica (TIYOUand McBrtarty industries of the Middle Stone Age (MSA) (Isaac 200% bin0 and McBreglty 2002). 1982; Clark 1994; McBrearty 2001). Evidence for a suite of novel behaviors that characterize- modern& RiwarcbaeologicalresearchmtheKapthurin recentforagcrsisassociatcdwithh4iddlePkistocene Formation focused on exposum north of the Ndau MSA sites, and the earliest Homo sapiens fossils arc River, witb only cursory exambation of more south- found with MSA artifacts (see Clark 1988; Deacoo erly areas (McBrearty a al. 1996566-570). slpvey and Deacon 1999; McBrearty and Brooks 2000 for in 2001 focused on -40 kmf of additional geologi- recent summaries). cally mapped Kapthurin Formation sediments (Martyn 1969; Tallon 1976) soutb of the Ndau River, These suggest significant behavioral data an area informally designated the "suuthem" changes during the Middle Pleistocene hominids by Kapthurin Formation. employing MSA technology. Previously, only broad contrasts between Acheulian and MSA sites were possible due to a lack of Afican sites with a well- Survey Objectives and Results preserved, dated, continuous sedimentary and archaeological record spanning the Acheulian-MSA FUM investigations conducted in the southern Formation were directed at recovery transition (Clark 1982; Wendorf d. 1994). By Kapthurin the er Of additid archae~logical and fossil ~~llect- examining this transition in detail, we may begin to sitn ing localities, well detailed tephrostratigraphic understand the causes underlying hominid behavioral as as obmtioas of the Bedded Tamember. Walkover adaptations that drove this change, as well as begin survey of known lasted fhm 8 May- 1 June to test recent hypotheses comlating the advent of exposures the MSA with hominid speciation and dispersal 2001, followed by test trenching at GnJh-75 and (Foley and Lahr 1997; Lahr and Foley 1998,200 I). Koimilot (GRm-74). Koimilot WBS later Chosen for Recent research in the Kapthurin Formation of Kenya, full-scale block excavation, with some 52-m2 surface which preserves a welldated sequence ofAcheulian excavated in 2001. 'lbnty sites, primarily and MSA sites, is therefore relevant to this scattm,werediscovatd~gthes\pvey,withfour discussion. sites re-investigated (Table 1 and Figure 1). Tht

6 NYAMEAKUAU No. 57Jum 2002

Figure 1: Archaeological and fossil sites hm the southern Kapthrvin Famatian. Included arc archaeological andpelaeOntologicalsites~the2001survcy(seeTable 1). Localities26-28wereinitialiyreportedbyMcBrtarty ef 2. I,sw, plant

7 Table 1: Southern Kapthurin FcUmation sits fomd during 2001 sur~y

Site Name SASES c4mtealt Wgraphy AtQibUtiOn Loc. 39 Galh-13 artifactsandfauna K4 Acheulian-MSA

Loc. 40 -12 artifactsandh K3 Acheulw Loc. 100 GnJh-64 mtifacts K4 ?ssngoan-MsA Loc. 101 GnJh-65 artifactsandf;auna K3 Actaculh Loc. 102 artifactsandfauna I K3 I Acheulian

~ ~~~ ~ - Lac. 103 artifactsandfauna K3 Acheulian

Loc. 104 artifacts K3 Indctuminate Loc. 105 GnJh-69 artifacts K3 and K4 ?Acheulian

19 Loc. 106 GnJh-70 artifacts K3 Indeterminate Loc. 107 GnJh-71 artifacts K3 Acheulian-MSA

~~ l1 Loc. 108 artifacts K4 Acheulian I I 12 Loc. 109 Grim-72 fa\pna K3 NIA

Loc. 110 -73 artifactssndhuna K3 ?MSA I 14 ~LQc.111 artifactsandfauna K3 Acheulian 15 Loc. 112 Galh-8 artifactsandfauna K4 Achedim 16 Loc. 113 GoJh-9 fauna K3 NIA 17 Loc. 114 GoJh-10 artifacts K3 Acheulian

18 Loc. 115 GnJh-76 artifacts K4 Acheulian

19 Loc. 116 Go&- 1 1 idfacts K4 Acheulian

GnJh-75 artifbasandfauna K4? MSA

21 Koimilot GnJh-74 artifactsandhuna K4 MSA (Loc. 118) 22 Loc. 119 GnJh-77 artifiicts K4 MSA 23 N y ogonyek GoJh- 1 artifactsandhum I K4Moloccnesed I MSA-LSA

24 Logumkum GoJi-7 artifacts and fauna Ilosowuani Fm. MSA-Rmt

8 NYAME AKUMA No. 57 June 2002

approximate spatial extent of each site was deter- containing rarc points and Levallois cores at GoJh- mined in the field, as was sedimentary and 13 and Grim-71, and more extensive s\irface scatters stratigraphic context. A Magellan 3 IS GPS unit pro- at Logumkum (GoJi-7), Nyogonyek (GoJh-1), and vided precise locational data, and usell for Koimilot (GnJh-74). Artifacts from Logumkum of Farrand et ul. 1976) include attribution of a site to period or industxy- were col- (Logumkum TV lected. Artifacts and fossils are presently housed at Lcvalloisanddiscoidalcores,Le~loiSpointSasweU as scrapers and bifacial points made on Levallois the Archaeology Division of the National Museums ' of Kenya (NMK) in Nairobi. flakes; rare artiEacts are of obsidian. These lie on an up-fiiultcd sedimentary sequence of lacustrine sedi- ment and W,assigned to the Ilosuowani Foxmation Southern Kapthurin Formation (Tiercelin and Vicens 1987; Le Turdu et aZ. 1995). Paleontology and Archaeology Nyogonyek is a large eroded area containing multiple dense patches of many of them The 2001 was successll in identifl- artifacts, typo- survey logically Stone Age, reported by Fanand ing a suite of previously unknown paleontological Later first et ul. (1976). An artifact concentration discovered and archaeological localitieshm southem exposum in 2001 consists ofnumerous Levallois flakes of the Kapthurin Formation. Sites ocdwithin cores, and points, produced by lineal well convergent alluvial and lacustrine sediments, in multiple as as temp andunipolarrecurrentmethods(cfB& 1994). The raYstratigraphic contexts. Although in situ fossils artifacts are apparently within down-faulted were observed and recovered hmmultiple locali- sediments of a lacustrine hies of the Middle Silts ties, fossil fauna are generally neither abundant nor and Gravels member (Tallon 1976; Fanand et ul. well preserved in the southern Kapthurin Formation. 1976; McBrearty 1999). Plant fossils are occasionally found, at times in growth position, within layers of &-fall tuf€(Tallon 1976, Excavation at Koimilot (GnJh-74) recovered personal observation). Two tephra layers rich in both two stratified MSA assemblages (Tryon and grass and leaf impressions bracket the excavations McBrearty 2002b) (Figures 3 and 4). Over 2000 ar- at Koimilot. tifacts were movered from the 36-m2excavation at Locus 1, the stratigraphically lower of the two Archaeological variability in the southern assemblages. occur in a -IO-cm-thick hori- Kapthurin Formation is comparable to that found Artifacts zon within fine-grained overbank sediments, north of the Ndau River (e.g. Cornelissen 1992; with refitting sets within the excavated area as well McBrearty et ul. 1996; McBrearty 1999). Sites at- hm as between the excavation and surface finds. Is+ tributable to the Acheulian Industrial Complex are lated teeth and tooth hgments comprise the recov- well represented handaxes and cleavers, produced by ered fauna The lithic assemblage consists of casu- from a range of fine-to-coarse grained lavas. These ally flaked large cobbles, well a dense debitage implements were prodyced from side and end-struck as as concentration and associated centripetally flaked flakes, from cobbles (GoJh-12) and the Kombewa cores that apparently reflect a Levalloismode of flake method (Gnlh-76). A large Levallois flake, similar production. Retouched pieces are rare. Locus 2 is to those used for handaxe production at LHA (Leakqr adjacent to and stratigraphically higher than 1 er a1 1969) was also recovered in situ from within Locus (Figures 3,4 and 6). The 12-m2 excavation recov- the Bedded Tuff at GnJh-62. Picks, found in the ered -150 from within a 10-an-thick zone Acheulian but often considered characteristic of the artifacts fiom five of the excavated meters. Artifacts Sangoan, were found in situ at GnJh-66, and have are associated with fine-to-coarse sands, and include large been reported fiom elsewhere in the Kapthurin For- length 2 10 points and elongated mation (Cornelissen 1995). Cores include a variety (max. cm)Levallois flakes, a centripetally flaked Levallois core, a blade of single and multiple platform, discoidal and rare core and ochre. Future research will systematically Levallois types. explore differences observed between Locus 1 and Middle Stone Age sites from the southern Locus 2 at Koimilot, as well as comparison of these Kapthurin Formation include sparse surface scatters assemblages with other sites, seeking to document

9 NYAMEAKUM No. 57June 2002

and explain temporal or functional variability within Kqthurin Formation audKalambo Falls (Clark 200 I) the MSA. is a necessary step for the formulation of hypotheses regarding hominid behavioral adaptations during and Tephrostratigraphy subsequent to the Acheulian-MSA transition. The additional sites discovered during the survey of the Multiple teph samples were collected from southern Kapthurin Formation, as well as excavation measured stratigraphic sections, and energy-disper- at Koimilot, expand both the site sample, as well as sive electron microprobe (Em)analysis is currently the time span of observable archaeological change in progress, using equipment housed at the mine in the Baringo basin. Geology Laboratories, Yale University. Preliminary field stratigraphic, petrographic and EMP analysis of glass geochemistry suggest that tuffs underlying Acknowledgements the archaeological deposits at Koimilot are compa- Work in the southern Kapthurin Formation was rable to the ‘hpper basaltic” portions of the Bedded conducted under a research permit &om the Govern- Tuff identified by Tryon and McBrearty (2002a). Im- ment of the Republic of Kenya (permit no. MOEST portantly, this makes Locus 1 and Locus 2 at Koimilo?, 13/00 1/3OC 229) and an exploration and excavation both assigned to the MSA, the youngest excavated license hmthe Minister for Heritage and Sports. assemblages thus far from the Kapthurin Formation, Funding was provided by the L. S. B. Leakey Foun- as all other known sites underlie these ”upper basal- dation, the Wcnner-Gren Foundation for Anthropo- tic” Bedded Tuff deposits. Additional tephra at logical Research, Inc., the Bill Bishop Memorial Koimilot include deposits not previously observed. Trust, and the National Science Foundation (BCS- These include the “Koimilot tuff” and basaltic tuf€ 0 I 18345). The success of the present investigation deposits that are not part of the established is due in part to my entire field crew, but most espe- tephrosequence of the Bedded Tuff member. The cially Boniface Kimeu, Mustah Kirika Waweru and “Koimilot tuff serves as a local marker bed, and is a Simon Katkya. Sally McBrearty and Andrew Hill fine-grained dacitic tuff which likely has a distant provided guidance and both material and moral sup- source outside the Baringo basin, offering the poten- port. Lastly, I thank my parents and Rhonda tial for long distance correlation such as has been Kauffman for their kindness and patience. achieved with deposits in the Lake Turkana basin (e.g. Brown 1994; Feibel 1999). References Additional preliminary EMP analyses have been undertaken for tephra at Logumkum, Nyogonyek and (30%-12. Ash deposits at Logumkum B&da, E. are unlike any presently known from the Kapthurin 1994 Le concept Levallois: VariabilitP des Formation, while those at Nyogonyek and GoJh-12 mdthodes. Paris: CNRS Editions. are tentatively identified as Bedded Tuff, with con- firmation pending subsequent laboratory reanalysis as well as the collection of additional field samples. Brown, F. H. 1994 Development of Pliocene and Pleistocene Conclusions chronology of the Turkana Basin, East Af- rica, and its relation to other sites. In R. S. The end of the Acheulian is a major Middle Cormccini and R. L. Ciochon, editors, In- Pleistocene archaeological event. The highly re- tegrative Paths to the Present: solved stratigraphic record of the Kapthurin Forma- PaleoanthropologicalAdvances in Honor tion provides the opportunity to examine basic is- ofF: Clark Howell. Englewd Cliffs, NJ: sues of the chronology of the Acheulian to Middle Prentice Hall, pp.285-3 12. Stone Age transition (Deino and McBrearty 2002; Tryon and McBrearty 2002a). Construction and comparison of local sequences of archaeological and paleoecological change, such as those from the

10 WAMEAKlJMA No. 57Junc 2002

Clark, J. D. Demo, A. and S. McBrearty 1982 The transition from Lower to Middle 2002 s9ArPArdating of the Kapthurin Fomation, Palaeolithic in the African continent. In A. Baringo, Kenya. Journal of Human Evolu- Ron- &or, The lhn.&ion From Lower tion 42: 185-2 10. to MiaWe Palaeolithic and the Origin of Modern Man,oxford: BAR. International Series 151: 235-255. Fanand, W. R, R W. Reddmg, M. H. Wolpoff and . T. Wright 1988 The Middle Stone Age of East Afiica and H. the beginninss of regional identity. Jw- 1976 An Archaeological Investigation on the nal of World Prehistory 2: 235-305. Loboi Plain, Baringo District, Kenya. Ann 1994 The Acheulian Industrid Complex in Af- Arbor: Muse~mof Anthropol~g~,UniVer- ricaandelsewhcre. InR S. Comccini and sity of Michigan Technical Reports No. 4. R. L. Ciochon, editors, Integrative Paths to the Past: Paleoanthrvpological Advances in Honor of E Clark Howell. Englewod Feibel, C. S. Clia, NJ: Prentice Hall, pp. 45 1470. 1999 Tephrostratigraphyand geological context 2001 Kalambo Falls Prehistoric Site, Vol. 3. The in pal~thropology.Evolutionmy Anth Earlier Cultum: MiaHe and Earlier Bone p~log~8: 87-100. Age. Cambridge: Cambridge University Press. Foley, R. A. and M. M. Lahr Cornelissen, E. 1997 Mode 3 technologies and the evolution of 1992 Site GnnE.17 and Its Implicationsfor the modern humans. Cambridge Archaeologi- Archaeology of the Midde Kqthurin For- cal J& 7: 3-36. mation, Baringo, Kenya. Tervuren: Musk Royale de 1'Afrque Centrale, Annales, Sci- ences Humaines 133. Hill, A. 1995 Indications du post-Acheulh (Sangoen) 2002 Paleoanthroplogicalresearch in the Tugen dam*la formation Kapthurin, Baringo, Hills, Kenya. Journal of Human Evolution Kenya. L 'Anthropologie 99: 55-73. 42: 1-10.

Cornelissen, E., A. Boven, A. Dabi, J. Hus, K. Ju Howell, F. C. Yong, E. Keppens, R. Langohr, J. Moeymns, P. Pasteels, M. Pieters, H. Uytterschaut, F. Van Noten, 1999 Paleo-demes, species clades, and and H. Workineh extinctions in the Pleistocene hominin record. Journal of Anthropological Re- 1990 The Kapthurin Formation revisited. Afri- search 55: 191-243. can Archaeological Review 8: 23-76.

Isaac, G L. Deacon, H. J. and J. Deacon 1982 The earliest archaeological traces. In J. D. 1999 Human Beginnings in South Africa: Uncov- Clark, editor, Cambridge Histoiy ofAfica, ering the Secrets of the Bone Age. Cape Vol. I, pp. 157-247. Cambridge: Cambridge Town: David Philip. University Press.

I? NYAMEAKUM Mo. 57June 2002

Lahr, M. M. and R Foley McBrearty, S. 1998 Towardsatheoryofmodemhumanorigins: 1999 Archaeology of the Kiipthurin Formation. Geography, demography, and diversity m In P. Andmw and P. Banham. editors, Lare mth- evolution. YedookqPW- Cenozoic Environments and Hominid cal Anthropoloog~4 1 : 137-1 76. Evolution: a Tribute to Bill Bishop. London: Geological Society, pp. 143-156. 2001 Mode 3, Homo klmei, and the pattern of human evolution m tht Middle Pleistocene. 2001 The Middle Pleistocene of east Afiica. In In I;. Barham and K. Robson-Brown, L. Barham and K. Robson-Brown, editors, Human Roors: Afiica and Asia in editors, Human Roots: Afika and Asia in the Mi&le Pleistocene. B~istol,England: the MWie Pleistocem. Bristol: Western Westan Academic and Specialist Press. Academic and Spe~ialistPress, p~.8 1-98. pp. 23-40.

McBmrty, S., L. C. Bishop and J. D. Kingston TWU, C. C~ussement,J.-J. Tier~elin,R Le C., W. 1996 Variability m traces of Middle Pleistocene Renauf J. Rolet, J.-P. Richut, J.-P. Xavier and D. hominid bcbavior m the Kapthurin Fonna- Coquelet tion, Baringo, Kenya. Joranol of Human 1995 Rift basin structure and depositional Evolution 30563-580. patterns interpreted a 3D remote using McBrearty, and A. Brooks sensingapproach:TheBaringoandBogoria S. S. basins, Central Ke~yaRiqEastAfiica. Bull. 2000 Iht ~voluti~atbat wasn’t: A mrised inter- Cen!res Rech Erplol: -Prod EIf Aquitaine pretation of the origin of modern human 19: 1-37. behavior. Journal of Human Evolution 39: 453-563.

Leakey,M.,P.V.Tobias,J.E.Martynaud RE.F. Leakey Stringer, C. B. and P. Andrcws 1969 An Acheulian indusw with prepared core 1988 Genetic and fossil evidence for the origin technique and the discovery of a contem- of modern humans. Science 239: 1263- porary hominid mandible at Lake Baringo, 1268. Kenya. Proceedings of the Prehistoric Su- ciety 3: 48-76. Tallon. P. W.J. 1976 stratigraphy, palaeoenvironments and Martyn, J. E. The geomorphology of the Pleistocene 1969 The geological history of the country be- Kapthurin Formation, Kenya. Ph.D. Disser- tween Lake Baringo and the Kerio River. tation, Queen Mary College, London. Baringo Ph.D. Dissatation. District, Kenya 1978 Geological setting of hominid fossils University of London. the and Acheulian artifitcts fhnthe Kapthurin For- mation, Baringo District, Kenya. In W. W. Bishop, editor, Geological Background to Fossil Man Edinburgh: Scottish Academic Press, p~.361-373. NYAMEAKUMA No. 57June 2002

Tiercelin, J.-J. and A Vmcea~,editors WeadoPZF.,A.ECloseandRSchild 1987 Le --Graben de Baringo-Bogoria, Rift 1994 Africa in the period of Homo sapiens Gregory, Kenya: 30,000 80s d'histoire neanderthal~isdcontempararies.Ins. hydrologique &Swimentape- .0d..e?m?S J. DeLaetetoL, edbs, HistorytfHaman- Rech Ihplm-Pt6d Ey-Aguitpine 11~249- a@, Vol. 1: &history adthe Beginnings 250. ofCiyilizcrtio. New Yo& Routledge and UNESCO, p~.117-135.

Tryon, C. A. and S. McBmuIy Wood, 2002a TepMgraphy and the Acheulian to B. Middle Stone Age transition. Jotanal of 1999 Plio-PieistoCenehomininsfiromthcBaringo Human Evolution 42: 21 1-235. Region, Kenya. In P. Andrews and P. Banbam, editors, Late Cenozoic Envkn- 2002b The Middle Stone Age of the southern mem and Human Evolution: A Tribute to Kapthlrrin JapM.J of Hunrun Formation. BiU 0ishop. London: Geological Society, Evolution A37. 42: pp. 113-122.