Sort order:  

Status: 1 Treffer   •   Seite 1 von 1   •   10 Artikel pro Seite

2018-08-28 18:35:40   •   ID: 2021

The ESA-MSA Mosaic in East Africa: MSA Point from Lake Victoria

Figure 1
Figure 2
This is a large and thin (11x6x0,7 mm) convergent tool ("Point") with lateral semi-abrupt retouches and a thinned base made from a greenish ignimbrite, found decennia ago in Kenya at the shores of Lake Victoria. It is a classic MSA lithic tool, allthough the raw material was pretty exotic.

During the Oldowan and Acheulian of East Africa most artifacts are made of volcanic rocks like basalt, rhyolites, obsidian and ignimbrites (Welded tuff).

During the MSA, Ignimbrite becomes very rare, but was for unknown reasons occasionally preferred for single artifacts (for example at Porc Epic cave, Dire Dawa (east-central Ethiopia)- see also: 1450 .

Recent research at Lake Victoria shows multiple MSA occupation scatters and sites from the Late (Middle) Pleistocene, older than 100 k.a. and younger than 36 k.a. Again there seems to be a temporal overlap of the latest MSA and earliest LSA over ten thousand of years, which was already discussed during a earlier post-see 1637 .

Levallois technique, unifacial and bifacial points are well developed at excavated sites in the Lake Victoria basin, and the artifact shown in this post fits well into the local Archeological framework, with some affinities to the Omo-Turkana region; see 2060 .

  • The late Acheulian, as recently shown at the Hugub site in N-Ethiopia shows an increase of smaller Handaxes- some of them have already the appearance of bifacial MSA-Points, a decrease in Cleaver production, and evidence of intensive use of resharpening techniques. This was taken by the excavators as proof of a higher rate of curation and longer tool life, compared to earlier Acheulean ensembles. Interestingly the dates for the latest Acheulean in East Africa from Ethiopia and Eritrea were reported to be 160- 125 k.a. BP- and therfore much later, than the MSA was fully established elsewhere in the region.

  • The earliest MSA- here defined as absence of LCTs and the use of prepared core techniques- developed side by side with the Acheulian in the well dated Kapthurin Formation west of Lake Baringo in the Kenyan Rift Valley

    At the Acheulian site of GnJh-03, large Levallois flakes from centripetally cores where produced and sometimes retouched into handaxes or scrapers. Blade tools also co-occur with this industry. Similar findings were present at LHA (Leakey's Handaxe site) dated to 545-509 k.a., thus preceding anatomical modernity in hominins.

    Blades, produced by a volumetric hard hammer technique are dated between 545 and 509 k.a. at GnJh-42 and GnJh-50. The blades are associated with discoidal cores and flakes. Blades have also been recovered from three younger sites in the Kapthurin formation that date to between 509 and 285k.a.

    At Kapthurin, the base of member K4, dated to 285 k.a., shows the change to a fully developed MSA without core tools and the presence of typical Levallois products.

    New excavations since 2001 at Olorgesailie, Kenyarevealed a similar picture: Acheulean occupations were followed by a long sequence of Middle Stone Age occupations without handaxes, beginning well before 315 k. a and ending before 64 k.a. Levallois technology was present already in the later Acheulean horizons of Members 11 and 13 of the Olorgesailie formation (between 625 and 550 k.a).

  • After 300 k.a. BP, the East African MSA is already fully developed. Lithics are characterized by points with unifacial and bifacial retouch on non-Levallois and Levallois blanks, partially made from "Classic”, but also from "Nubian "cores. This is for example the the case at Gademotta (ETH-72-8B before 276±4 k.a BP; ETH-72-6 after 183±10 k.a BP) and at Kulkuletti (200–300 k.a BP)