. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 108 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 9. Floating rig utilized to obtain deep sediment cores in operation in False Bay. are being processed by J. Vogel of the Council for Scientific and Industrial Research for radiocarbon age determination. The preliminary findings, together with those reported by Kriel (1965), indicate a Holocene age apart from the deeper parts of some cores which extend into the late Pleistocene. Core 1 from northern False Bay extended to a depth of 33,5 m. Below a depth of
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 108 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 9. Floating rig utilized to obtain deep sediment cores in operation in False Bay. are being processed by J. Vogel of the Council for Scientific and Industrial Research for radiocarbon age determination. The preliminary findings, together with those reported by Kriel (1965), indicate a Holocene age apart from the deeper parts of some cores which extend into the late Pleistocene. Core 1 from northern False Bay extended to a depth of 33,5 m. Below a depth of 19 m silt and shelly sand predominate and contain a variety of molluscs, some of which are of marine affinity (R. N. Kilburn, pers. comm.). This accords with the findings of Phleger (in press) who detected foraminiferal evidence of marine conditions, with unrestricted access to oceanic water at depths of 21,5 m and at the bottom of the core. Sedimentological evidence for high energy processes comes from 50 cm of reworked Cretaceous at the base, but this is overlain by deposits of sand and mud suggesting rapid reduction in energy as a result of deepening and the sheltering effect of a barrier. Bioturbated mud containing broken, thin-shelled molluscs makes up all but the basal 3 m of Core 2. Phleger (in press) reports the presence of gypsum crystals at depths of between 18,5 and 25,5 m. This indicates that even during the early Holocene there were periods of intense desiccation initiated by effec- tive lagoonal confinement and lack of appreciable inflow of fresh water. Phleger notes foraminiferal indications of marine conditions just above transgressive white sands at the base of the core, and at depths of 4,5-5 Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original South African Museum. Cape Town : The Museum
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
