Revisiting Umhlatuzana Rock Shelter, South Africa: First geoarchaeological results

Abstract

In 2018 we initiated a geoarchaeological investigation of Umhlatuzana rock shelter. Our aim is to clarify the depositional environment of the Middle and Later Stone Age (MSA-LSA) assemblages (~70 – 20 ka), in light of suggestions of post depositional sediment movement (Kaplan 1990). The Pleistocene sequence shows few visible stratigraphic boundaries. Sedimentological analysis allows us to evaluate the depositional environment.

Full text

Revisiting Umhlatuzana Rock Shelter, South Africa:
First geoarchaeological results
Sifogeorgaki Irini1; Dusseldorp Gerrit1,2
1: Leiden University, Faculty of Archaeology 2: Palaeo-Research Institute, University of Johannesburg
ACKNOWLEDGEMENTS
Victor Klinkenberg for his help with find
cluster analysis
VU Amsterdam Lab for the grain size and
LOI analyses
Umhlatuzana stratigraphy
West Prole
Figure 1 Map illustrang sites with MSA-LSA sequences in South
Africa. BMPL: Boomplaas Cave; BP: Border Cave; EBC: Elands Bay
Cave; RCC: Rose Coage Cave; SEH: Sehonghong rock shelter; STR:
Strathalan B. rock shelter; UMH: Umhlatuzana rock shelter.
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
INTRODUCTION
In 2018 we initiated a geoarchaeolog-
ical investigation of Umhlatuzana rock
shelter. Our aim is to clarify the depo-
sitional environment of the Middle and
Later Stone Age (MSA-LSA) assemblages
(~70 – 20 ka), in light of suggestions of
post depositional sediment movement
(Kaplan 1990). The Pleistocene sequence
shows few visible stratigraphic bound-
aries. Sedimentological analysis allows
us to evaluate the depositional environ-
ment.
RESULTS & CONCLUSIONS
• Discrete high and low find density lay-
ers
• Horizontal orientation of find density
pattern suggests limited post-deposi-
tional movement
• Sedimentary colour difference in Pleis-
tocene due to high-moisture units
• Grain size analysis suggests contin-
uous sedimentation through in situ
weathering of rock shelter
• Low- and high- density layers proba-
bly relate to low- and high- occupa-
tional events
METHODS
Our stratigraphic assessment is based
on field observations combined with ge-
ospatial data of the piece-plotted finds
over 2cm. To assess depositional and
post- depositional processes, we have
conducted grain-size using a laser de-
fractor, pH, and Loss on Ignition analy-
ses. Analysis of the piece-plotted finds
sheds light into potential mixing of the
finds and istinguishes levels of high oc-
cupation intensity.
Figure 2 A Ternary graph of grain size, B 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 derived from Bell and Lindsay
1999.
10379
16326
Concreted 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
Calibrated radiocarbon
and OSL dates (years BP)
(Kaplan 1990, Lombard et. al 2010)
Recent upper layer
In situ combistion features
Charcoal-rich layers
Dug-up/ bioturbated features
61
Higher find density layer
Lower find density layer
High find density , high moisture layer
Low find density, high moisture layer
13
50b
20cm
49b
51b
63
53
10379
16326
Concreted 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
Calibrated radiocarbon
and OSL dates (years BP)
(Kaplan 1990, Lombard et. al 2010)
Recent upper layer
In situ combistion features
Charcoal-rich layers
Dug-up/ bioturbated features
61
Higher find density layer
Lower find density layer
High find density , high moisture layer
Low find density, high moisture layer
13
50b
20cm
49b
51b
63
53
ACHATINA (LAND SNAIL)
BEADS, IRON AGE
OSTRICH EGGSHELL, NAS-
SARIUS KRAUSSIANUS BEAD,
HOLOCENE LSA
BACKED SEGMENT, MSA
UNIFACIAL POINT, MSA
UNIFACIAL POINT, MSA
FRAGMENT OF BIFACIAL
POINT, MSA
A
B