Taphonomy, environment or human plant exploitation strategies?: Deciphering changes in Pleistocene-Holocene plant representation at Umhlatuzana rockshelter, South Africa

The period between ~40 and 20 ka BP encompassing the Middle Stone Age (MSA) and Later Stone Age (LSA) transition has long been of interest because of the associated technological change. Understanding this transition in southern Africa is complicated by the paucity of archaeological sites that span this period. With its occupation sequence spanning the last ~70,000 years, Umhlatuzana Rock Shelter is one of the few sites that record this transition. Umhlatuzana thus offers a great opportunity to study past environmental dynamics from the Late Pleistocene (MIS 4) to the Late Holocene, and past human subsistence strategies, their social organisation, technological and symbolic innovations. Although organic preservation is poor (bones, seeds, and charcoal) at the site, silica phytoliths preserve generally well throughout the sequence. These microscopic silica particles can identify different plant types that are no longer visible at the site because of decomposition or burning to a reliable taxonomical level. Thus, to trace site occupation, plant resource use, and in turn reconstruct past vegetation, we applied phytolith analyses to sediment samples of the newly excavated Umhlatuzana sequence. We present results of the phytolith assemblage variability to determine change in plant use from the Pleistocene to the Holocene and discuss them in relation to taphonomical processes and human plant gathering strategies and activities. This study ultimately seeks to provide a palaeoenvironmental context for modes of occupation and will shed light on past human-environmental interactions in eastern South Africa.NWOVidi 276-60-004Human Origin

Two methods on one stone: integrating visual and analytical techniques to clarify lithic raw material utilization in the Middle and Later Stone Age at Umhlatuzana rockshelter (South Africa)

We develop a study protocol to efficiently and accurately identify the raw material categories constituting the lithic assemblages at Umhlatuzana rockshelter, South Africa. We combine visual and analytical methods to establish a raw material database and to provide a more accurate insight into raw material selection during the Pleistocene Middle and Later Stone Age occupational sequence of Umhlatuzana. The protocol combines petrological properties (as studied on micromorphological samples), elemental composition of the specimens (as measured with p-XRF) and visual characterization by lithic analysts. We tested the protocol by applying it to a sample of piece-plotted lithics from four spits across the stratigraphic sequence. We document the intensive use of sandstone accounting for 25% of the tested sample. We also report a larger importance of hornfels and lower proportion of quartz than was reported in previous analyses (Kaplan 1990). The combination of micromorphological and p-XRF analysis of the Umhlatuzana assemblages demonstrates that with only visual inspection, the variability of raw materials used may be misinterpreted. With accurate raw material datasets, we are better equipped to answer techno-economic questions of the southern African Stone Age. NWOVidi 276-60-004Human Origin

Excavations at Umhlatuzana rockshelter

We are conducting geoarchaeological fieldwork and analysis of Umhlatuzana, a rockshelter in KwaZulu-Natal. Due to lockdowns, we missed our 2020 wintery encounters with spitting cobra’s and vervet monkeys. It did give us the time to concentrate on publishing our first results (Sifogeorgaki et al. 2020). Our work aims to clarify the stratigraphic integrity of the Pleistocene part of the sedimentary sequence associated with Middle and Later Stone Age archaeological materials. NWOVidi-276-60-004Human Origin

New excavations at Umhlatuzana Rockshelter, KwaZulu-Natal, South Africa: a stratigraphic and taphonomic evaluation

Umhlatuzana rockshelter has an occupation sequence spanning the last 70,000 years. It is one of the few sites with deposits covering the Middle to Later Stone Age transition (~40,000–30,000 years BP) in southern Africa. Comprehending the site’s depositional history and occupation sequence is thus important for the broader understanding of the development of Homo sapiens’ behavior. The rockshelter was first excavated in the 1980s by Jonathan Kaplan. He suggested that the integrity of the late Middle Stone Age and Later Stone Age sediments was compromised by large-scale sediment movement. In 2018, we initiated a high-resolution geoarchaeological study of the site to clarify the site formation processes. Here, we present the results of the excavation and propose a revised stratigraphic division of the Pleistocene sequence based on field observations, sedimentological (particle size) analyses, and cluster analysis. The taphonomy of the site is assessed through phytolith and geochemical (pH, loss on ignition, stable carbon isotope) analyses. The results indicate a consistent sedimentological environment characterized by in situ weathering. The analysis of the piece-plotted finds demonstrates semihorizontal layering of archaeologically dense zones and more sterile ones. There was no indication of large-scale postdepositional sediment movement. We show that the low-density archaeological horizons in the upper part of the Pleistocene sequence are best explained by the changing patterns of sedimentation rateNWOVidi 276-60-004Human Origin