Middle Stone Age stratigraphy and excavations at Die Kelders Cave 1 (Western Cape Province, South Africa): The 1992, 1993, and 1995 field seasons

Die Kelders Cave 1, first excavated under the direction of Franz Schweitzer in 1969-1973, was re-excavated between 1992 and 1995 by a combined team fr om the South African Museum, SUNY at Stony Brook, and Stanford University. These renewed excavations enlarged the artefactual and faunal samples from the inadequately sampled and less intensively excavated lower Middle Stone Age (MSA) layers, increased our understanding of the complex site formation processes within the cave, enlarged the hominid sample from the MSA deposi ts, and generated ESR, TL, and OSL dates for the MSA layers. Importantly, t hese new excavations dramatically improved our comprehension of the vertica l and lateral characteristics of the MSA stratigraphy. Surface plotting of the MSA layers has led to the identification of at least two major zones of subsidence that significantly warped the layers, draping some along the er oding surface contours of major blocks of fallen limestone roof rock. A thi rd zone of subsidence is probably present in the older excavations. Dramati c roof falls of very large limestone blocks occurred at least twice-once in the middle of Layer 4/5 where the roof blocks were only slightly weathered after collapse, and at the top of Layer 6 where the blocks weathered heavi ly after collapse, producing a zone of decomposed rock around the blocks. M any of the sandy strata are cut by small and localized faults and slippages . All of the strata documented by Schweitzer's excavations are present thro ughout the exposed area to the west of his excavated area, where many of th em thicken and become more complex. Layer 6, the thickest MSA layer, become s less diagenetically altered and compressed to the west. (C) 2000 Academic Press.