Return to the East African Stone Age – further adventures at the site of Isimila, Tanzania.
Team members: Dr James Cole (University of Brighton), Dr John McNabb (University of Southampton), Dr Martin Bates (University of Wales Trinity St David), Dr Amandus Kwekason (National Museum of Tanzania), Dr Pastory Bushozi (University of Dar es Salaam), Professor David Nash (University of Brighton).
Research funded by: the University of Brighton School of Environment & Technology Research Initiative Fund (Cole, Bushozi, Kwekason), the Society of Antiquaries (McNabb and Nash) and the Quaternary Research Association (Bates).
In September 2015 a team of international researchers met in Dar es Salaam, Tanzania, to begin two weeks of investigation into various aspects of the Stone Age site of Isimila. Isimila is a site that is cited in almost every major publication on the Palaeolithic of Africa and beyond, with a potted research history from 1950s –2000s with major excavations being conducted in the late 1950’s by Clark Howell of the University of Chicago. However, the site is still poorly understood in terms of its chronology and broader landscape context. Initial U-series dating work conducted in the early 1970’s returned a date of c.260 thousand years from the middle of the sequence and c.60 thousand toward the top. However, the relationship of the excavated artefacts to these initial dates is far from clear. Dating work conducted by the team in September 2014 is still under analysis and the 2015 field season was aimed at giving the team a greater understanding of the Stone Age artefacts from the site; and the geology of the site and the surrounding areas.
There were two main components of the 2015 field season the first was aimed at trying to ascertain the raw material procurement strategies of the stone tool makers at Isimila. This part of the project was led by Dr John McNabb and included Professor David Nash and Dr Amandus Kwekason. In order to understand the raw material procurement and use of the stone by the Stone Age hominins at Isimila the team trialled a technique using Portable X-ray Florescence (PXRF) which is a portable device that can measure the chemical composition of various rock types. Initially they measured a number of artefacts from Isimila held at the National Museum in Dar es Salaam and then applied the same technique to rock outcrops in the surrounding landscape near the site of Isimila.
The second component of the field work undertaken by Dr Martin Bates and Dr James Cole was concentrated within the site of Isimila itself (picture below) where we were primarily concerned with mapping the various sediment layers throughout the erosional feature (karongo) and characterising the differnet sediment layers.
The importance of the sediment mapping and characterisation is that understanding the distribution of the sediment and the formation processes will help us to further appreciate the nature of the archaeological record and how such amazing artefacts are present at the site. The ultimate aim being that once we understand the geology of Isimila we will then be in a strong position to interpret the archaeology that is present there. The following pictures show some of the work done by the team in surveying the site and characterising the sediments.