Stratigraphic assessment of Umhlatuzana
Rock Shelter, South Africa
Sifogeorgaki Irini
1; Dusseldorp Gerrit
1,21: Leiden University, Faculty of Archaeology 2: Palaeo-Research Institute, University of Johannesburg
INTRODUCTION
Umhlatuzana is an important rock shelter site for the study of the Middle and Later Stone Age in South Africa (~70,000 BP - 1,800 CE). Previ-ous excavations (Kaplan 1990) report sediment movement. Unclear stratigraphic integrity has led to the site being underused. This is especial-ly important for the MSA/LSA transition, which is only known from very few sites.
We initiated a high-resolution geoarchaeological study aimed at clarifying the depositional history of the archaeological assemblages.
Our stratigraphic assessment is based on a com-bination of field observations with geospatial, sedimentological, and geochemical analyses. Specifically, we have conducted grain-size, find distribution, pH, and Loss on Ignition analyses. Additional geoarchaeological work including micromorphological analysis is underway to ad-dress outstanding questions on the stratigraphy of the site.
Contact: Dashed when approximately located
10379 16326
Concrete ash layers
Dark Brown sand
16326 +/- 439 2971 32503 41907 70500 70500 60000 41900 33 1a 1b 1c 2 4 23 7 58 57 5 5 56 60 22 41 9 48 15 51 49 14 11 5 50a 12 10 43 Callibrated radiocarbon
and OSL dates (years BP)
(Kaplan 1990, Lombard et. al 2010)
Modern upper layer
In situ combistion features
Charcoal-ritch layers
Dug-up/ highly bioturbated features
61
Higher find density layer
Lower find density layer
High find density , high moisture layer
Low find density, low moisture layer
13
50b
49b
Figure 1 Map illustrating sites with MSA-LSA sequences in South
Af-rica. BMPL: Boomplaas Cave; BP: Border Cave; EBC: Elands Bay Cave; RCC: Rose Cottage Cave; SEH: Sehonghong rock shelter; STR: Strath-alan B. rock shelter; UMH: Umhlatuzana rock shelter.
ACKNOWLEDGEMENTS
RESULTS & CONCLUSIONS
• Continuous mechanism of sedimentation through-out the sequence
• Source material accumulated by in-situ weathering • Pleistocene-Holocene hiatus consistent with
pat-terning in pH and LoI results
• Sedimentary colour difference in Pleistocene due to hydraulics of the area resulting in high moisture units • Current stratigraphic assessment does not support
sediment movement in the sequence
Femke Reidsma for her help with pH analysis
Victor Klinkenberg for his help with find cluster analysis VU Amsterdam Lab for the grain size and LOI analyses
Concreted ash layers Dark Brown sand
Modern upper layer In situ combustion features
Charcoal-rich layers Dug-up/ highly
bioturbated features
Higher find density layer Lower find density layer High find density, high moisture layer
Low find density, low moisture layer
Umhlatuzana stratigraphy
West Profile
Figure 2 A: Photo of the excavated western profile; B: Umhlatuzana rock shelter; C: In situ MSA unifacial point.
A
B
C
Figure 4 Particle size distribution curves for identified stratigraphic units 1b,5, 7, 9, 10, 11, 15, 33, 48, 50. The mean grain size of the rock shelter was de-rived from Bell and Lindsay 1999.
Figure 3 Stratigraphic drawing of Umhlatuzana rock shelter based on field
observations and find density cluster analysis.
METHODS
Bell, F. G., & Lindsay, P. (1999). The petrographic and geomechanical properties of some sandstones from the Newspaper Member of the Natal Group near Durban, South Africa. Engineering Geology; Kaplan, J. (1990). The Umhlatuzana Rock Shelter sequence: 100 000 years of Stone Age history. Southern African Humanities, 2(0); Lombard, M., Wadley, L., Jacobs, Z., Mohapi, M., & Roberts, R. G. (2010). Still Bay and serrated points from Umhlatuzana Rock Shelter, Kwazulu-Natal, South Africa. Journal of Archaeological Science, 37(7), 1773–1784; . Map based on SRTM 2000, NASA/JPL/NIMA.
