Stratigraphic assessment of Umhlatuzana Rock Shelter, South Africa

Abstract

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). Previous excavations (Kaplan 1990) report sediment movement. Unclear stratigraphic integrity has led to the site being underused. This is especially 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.

Full text

Stratigraphic assessment of Umhlatuzana
Rock Shelter, South Africa
Sifogeorgaki Irini1; Dusseldorp Gerrit1,2
1: 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 illustrang sites with MSA-LSA sequences in South Af-
rica. BMPL: Boomplaas Cave; BP: Border Cave; EBC: Elands Bay Cave;
RCC: Rose Coage 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 Prole
Figure 2 A: Photo of the excavated western prole; B: Umhlatuzana rock shelter; C: In situ MSA unifacial point.
AB C Figure 4 Parcle size distribuon curves for idened stragraphic 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 Stragraphic drawing of Umhlatuzana rock shelter based on eld
observaons and nd density cluster analysis.
METHODS
Bell, F. G., & Lindsay, P. (1999). The petrographic and geomechanical properes 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
Humanies, 2(0); Lombard, M., Wadley, L., Jacobs, Z., Mohapi, M., & Roberts, R. G. (2010). Sll 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.
e.sifogeorgakis@arch.leidenuniv.nl