Fig 1.
Schematic depiction of the three Nubian core types following [58].
Fig 2.
Location of UPK7 and nearby sites in southern Africa, including Mertenhof (MRS), Hollow Rock Shelter (HRS) and Klipfonteinrand (KFR).
Inset (top right) are silcrete cobbles from Swartvlei. Landsat panchromatic EDM+ scene downloaded from Global Land Cover Facility (University of Maryland) at http://glcf.umiacs.umd.edu/index.shtml. Original scene sourced and modified from [125].
Fig 3.
Panoramic view of UPK7 (black circle) adjacent to the Biedouw River.
Table 1.
Characteristics of major Middle Stone Age industries in southern Africa, following [41, 83, 84, 92–94].
Fig 4.
Overview of the UPK7 surface scatter indicating the distinct spatial patterning of time-sensitive cultural elements.
Fig 5.
View of the Mertenhof archaeological site with focus on the rock shelter entrance.
Fig 6.
Distribution of artefacts in the main area at UPK7, with a focus on silcrete (white circles), unifacial points (nested triangles), and cores with Nubian characteristics (nested circles).
Fig 7.
Cores with Nubian characteristics from UPK7 and Mertenhof.
UPK7: a, c, h, f & i, silcrete; b & j, chert; d, hornfels; e & g, quartzite. Mertenhof: k, silcrete. White arrows on photos show direction of lateral and distal preparation; yellow arrows show direction(s) of preferential blows.
Table 2.
Summary statistics of metrics taken on the Nubian cores from UPK7.
Fig 8.
Scatter plots showing length by width (in mm) for Nubian-like cores from UPK7 with indication of raw material (left) and Nubian core type (right).
Fig 9.
Levallois points with Nubian characteristic from UPK7 and Mertenhof.
UPK7: a, quartzite; b-d, silcrete; Mertenhof: f & g, both silcrete. White arrows show directions of preparation removals. Overshot flake from Nubian-like core (e, silcrete). Inset images for Mertenhof points show damage immediately below flake platforms.
Fig 10.
Distribution of artefacts in the Mertenhof sequence.
Non-silcrete artefacts (filled grey circles) and silcrete artefacts (white circles) are shown from squares 4 and 6 only (see S2 Text for square locations). Unifacial points (nested triangles), backed artefacts (black circles), bifacial points and thinning flakes (inverted black triangles) are shown from all excavated squares, including the deep sounding square 3. The single nested circle represents a core with Nubian characteristics. Frequency histograms for all artefacts (grey line and scale) and silcrete artefacts (black line and scale) are generated using arbitrary 20 mm horizontal bins.
Table 3.
Number of artifacts and percentages of major raw material types by stratigraphic unit from Mertenhof (pit and burial units excluded).
Table 4.
Frequency of major artefact types by stratigraphic unit from Mertenhof (pit and burial units excluded).