RESEARCH

CURRENT PROJECTS

Mid-Pleistocene environments of the lower Vaal river (MINERVA) 2019-2021 Read more here

Excavations and palaeoenvironments at Pniel, lower Vaal River, South Africa (Principal Investigator) 2017 – 2019

This project is the precursor to the MINERVA project above. In two field seasons at Pniel we surveyed the area along the Vaal river and established digital grid for excavation. Four areas were opened and which yielded fauna and lithic artefacts.

Funded by the Quaternary Research Association (QRA) Quaternary Research Fund; Rust Family Foundation & The Palaeontological Scientific Trust (PAST), Johannesburg, South Africa.

20170622_104933

Diamonds, missionaries and early collectors: History of Collections from Pniel, South Africa (Principal Investigator) 2017 – ongoing

The site of Pniel on the Vaal river (see project above) has, long before our modern excavation project, attracted diamond miners, missionaries and artefact collectors, particularly in the late 19th and early 20th century. As a results, isolated artefacts from Pniel found their way into numerous museum collections in Europe and North America. This project will document the artefacts from Pniel at a number of major museums (in Canada, the UK and France amongst others) and trace their collection history in connection to the emergence of Palaeolithic archaeology as a discipline in South Africa.

Museum collections studied: Royal Ontario Museum, British Museum, Pitt Rivers Museum, Museum of Archaeology and Anthropology Cambridge, McGregor Museum Kimberley.

Wonderwerk Cave Excavation Project, South Africa (Spatial Data Manager) 2013 – ongoing

Wonderwerk Cave in the southern Kalahari currently has the oldest evidence for hominin use of cave sites in the world as well as evidence for use of fire by hominins c. 1 million years ago. Its archaeological layers span almost two million years, resulting in an unique archaeological and sedimentological repository in this arid region. The Wonderwerk Cave research project is lead since 2004 by Michael Chazan (university of Toronto), Liora Horwitz (The Hebrew University Jerusalem) and Francesco Berna (Simon Fraser University) and includes c. 30 international researchers. I joined the team in 2013 at the start of a phase of new excavations into the Acheulean deposits. My main responsibilities include the setting up of a digital grid system in the cave, the development of an excavation protocol using piece-plotting with a total station of all finds and database creation and management. Find more information at www.wonderwerkcave.com.

_MG_2033

Drivers of climate in the summer rainfall zone of southern Africa during the Mid-Pleistocene 2016 – ongoing

Following the results from my DPhil thesis on Wonderwerk Cave (see below), I am exploring  the possible drivers leading to a significantly wetter environment compared to today in the region using climate models. Major collaborators include Hiromitsu Sato, University of Toronto, Canada and Douglas Kelley, Centre for Ecology and Hydrology, UK.

PAST PROJECTS

Two million years of environmental change: a case study from Wonderwerk Cave, South Africa – DPhil thesis. Supervisor: Julia Lee-Thorp.

Abstract:
The arid interior of South Africa lacks long, continuous and well-dated climate and environmental proxy records that can be compared with cultural sequences and with broader global climate records. This thesis develops the first substantial terrestrial environmental sequence for the interior of southern Africa at the site of Wonderwerk Cave, spanning two million years of prehistory. Changes in vegetation and humidity over time were investigated by means of carbon and oxygen stable isotope analysis on fossil herbivore enamel and ostrich eggshell, creating two independent proxy datasets. The Holocene record was used as a baseline for comparing the Pleistocene sequence, but required chronological tightening. Therefore, nine new radiocarbon dates were obtained, and calibrated and modelled with existing dates to provide a firmer chronology.
The ostrich eggshell isotope record suggests arid but variable conditions, with distinct phases of increased humidity in the Early Pleistocene and mid-Holocene. Enamel stable isotope results show clear differences in local resource availability between the Early and Mid-Pleistocene, and then between the Pleistocene and Holocene, with an overall trend of increasing aridity. In particular, the onset of dietary specialisation in grazers at 0.8Ma is linked to expanding C4 grasslands. Aridity was not the driver behind the increase in C4 grasses, but changing pCO2 levels at the Mid Pleistocene transition were identified as a possible key factor. The presence of C3 and C4 grasses in the Early Pleistocene, when compared to the domination of C4 grasses today, was fostered by reduced rainfall seasonality. Regional independent developments have to be considered, as other regions in South and East Africa show C4 dominated diets in herbivores at earlier times than at Wonderwerk Cave. In the Holocene, higher temporal resolution indicates phases of environmental change coinciding with changes in the cultural record.

Funding was provided by the Boise Trust Fund, The Quaternary Research Association New Research Workers’ Award, a NRCF grant to Lee-Thorp and Ecker for radiocarbon dating, the German Academic Exchange Service (DAAD), the Keble Association, Keble College and the School of Archaeology, University of Oxford.

Ostrich eggshell: Preservation, dating and environmental analyses.

Ostrich eggshell is abundant in archaeological sites in southern Africa. It is easily recognisable and can be used for palaeoenvironmental analsyis as well as for dating by various methods. In a collaboration lead by Julia Lee-Thorp (University of Oxford) and Kirsty Penkman,  (University of York) we have been collaborating on amino acid dating and protein diagenesis of ostrich eggshell, resulting amongst others in the paper Demarchi et al. 2016 in eLife. Another independent collaboration with Jennifer Botha-Brink, (National Museum Bloemfontein) on ostrich eggshell paleontology and palaeoenvironments, resulted in the paper Ecker et al. 2015 in Palaeoecology of Africa.

P1030679

Stable isotope analyses on the fauna from Payre, (Ardeche, France) – Magister thesis. Supervisors: Herve Bocherens and Nicholas Conard. Published in Ecker et al. 2013 Journal of Human Evolution.

Abstract: The Middle Palaeolithic site of Payre (France, Ardèche) yielded three layers with lithics, faunal and hominid remains from Neanderthals. Carbon and oxygen stable isotope analyses were conducted on 49 teeth of red deer (Cervus elaphus), horse (Equus sp.), aurochs/steppe bison (Bos primigenius/Bison priscus), rhinoceros (Stephanorhinus kirchbergensis), tahr (Hemitragus bonali), chamois (Rupicapra rupicapra), giant deer (Megaloceros giganteus), roe deer (Capreolus capreolus), alpine ibex (Capra ibex), cave bear (Ursus spelaeus), brown bear (Ursus arctos), wolf (Canis lupus), red fox (Vulpes vulpes) and Neanderthal (Homo neanderthalensis). The results of 25 former analyses were added to the results of the present study. The general distribution of the results, the differences between layers and habitat reconstruction are discussed.
Payre is an advantageous site due to its geographical position. There are diverse biotopes to explore: the river valleys, the limestone plateau and the slopes. Different raw materials for stone tool making are available locally. The lithic technology and hunting strategies do not change through the entire sequence. Climatic change did not have an influence on the Neanderthal subsistence strategy. The main influence on stable isotopes in herbivores is the local topography. In the Rhone valley, with high humidity as well as tree groups with grass in clearings, Neanderthals hunted horses, aurochs, bison and rhinoceros. On the plateau, with more evaporation due to shrub vegetation and the limestone bedrock, Neanderthals hunted deer, aurochs and bison. Small herbivores from steep slopes were brought into the cave by Neanderthals and/or carnivores.
Next to ecological reconstruction, Neanderthal subsistence, diet and habitat use were also investigated. Although the diet of the sampled Neanderthal seemed to be mainly carnivorous, there was a difference in preferred prey compared to the two sampled wolves. There are some limitations like the possible influence from non-local sources or the amount of plant or fish in the diet which could not be determined.
The results of stable isotopes were compared to the results from dental wear analyses, done on the same teeth. Grazing and browsing does not seem to bind animals to a specific habitat in the C3 environment which is reflected in the isotope values. In the case of Payre, only dental wear can distinguish between grazers and browsers, while only stable isotopes can define habitat use. Both methods supplement each other.
The stable isotope results from Payre were compared to results from Atapuerca (Spain), Valdegoba Cave (Spain) and Kent’s Cavern (England). In general, all four studies show the same distribution of herbivore and carnivore species. The sampled carnivores have more negative δ13C mean values than the herbivores. The δ18O mean value, on the other hand, is always more positive in carnivores. The resource use is influenced by geographic location of the individual sites. Cervus elaphus, Equus sp. and Rhino species in all sites fall in the same range except in Payre. All four studies show the potential of stable isotope analyses on tooth enamel as a tool to investigate the ecology in a C3 environment.
This study is the first one to investigate Neanderthals and their C3 environment on carbon and oxygen isotopes on tooth enamel. It is also the first direct comparison of dental wear and stable isotope analyses on a wide range of herbivore species. It is a basis for further investigations, for example questions about seasonality, mobility or differences between individuals and hominid species.