Re-examination of the lower stratigraphy in the classic section, limeworks site, Makapansgat, South Africa |
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Authors: | A G Latham A I R Herries A G M Sinclair K Kuykendall |
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Institution: | (1) Archaeology Department, Liverpool University, Hartley Building, L693GS Liverpool;(2) Department of Anatomical Sciences, University of Witwatersrand, Johnannesburg, South Africa |
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Abstract: | At the end of Member 2 times, remnant mammillary-form stalactites in the roof and wall contacts show that an irregular wedge-shaped
space existed from the Classic Section out to the Cone area. It was into this space that hyenas and other denning animals
were able to gain access from an as yet unfilled Cone area. During the mining operations of the 1920’s, Eitzman (1958) recollects
entering an impressive bone breccia resembling a charnel house. We suggest that it is most probable that the Grey Breccia
corresponds to his main breccia as only the area on top of Member 2, between the dolomite walls, roof and stalagmite boss
has the required volume. It also lies at the end of an incline first dug by the miners, (still in existence), and at the end
of which he was able to note some of the deposits. The bone breccias at the same level at the back of the Cone suggest that
other dens were created at about this time.
As the roof continued to retreat upslope and more material was washed in or fell in from the surface so more sediment was
winnowed into the back of the Cone. At some stage this allowed prey animals to enter the Cone area and gain access between
the speleothem barrier to the area of the Classic Section. As most Australopithecine fragments came from this breccia, it
seems likely that, as with Swartkrans, the hominid fragments are the result of predation. Then as sediments continued to wash
into the Cone area, the Classic Section and the back of the Cone became inaccessible for denning purposes.
Large speleothem remnants embedded in sediment starting part-way up the Cone shows that a roof continued to exist in this
area for some time. In fact, even today, although bits of speleothems can be found in the eroded hardened surface sediments
there are few, if any, dolomite blocks. We presume that they were removed along with the upper part of the infilled, cavern
along with the country rock as the surface continued to erode.
Although it may not be possible to reconstruct a complete strati-graphic sequence involving the whole of the site, we have
presented summary of evidence here that shows it is possible to trace stratigraphic relationships from the base of the Ancient
Entrance to the top of the Cone and which includes the Grey Breccia and the two other bone breccias. Present work is focussed
on completion of a new chronology by comparing our site magnetostratigraphy with the global polarity timescale.
The speleothem deposition today in any of the caves of the Makapansgat area, with its annual rainfall of about 700mm, is extremely
low. It is commonly recognised by karst geomorphologists (eg, Ford and Williams, 1989) that massive deposits of speleothem
are characteristic of humid tropical to semi-tropical karsts. Hence, at the time of their formation some 3 Ma or more ago,
the massive speleothem deposits are evidence for a warmer, and certainly a much wetter, climate than that of today. |
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Keywords: | Limeworks Makapansgat South Africa Australopithecine Stratigraphy Magnetostratigraphy |
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