Nanaga Formation: Comprises semi-consolidated,
cross-beddedsandstones.
Calcrete layers containing
rhizoliths, and reddish, clay-rich
soils are also found. These were deposited in
coastal paleo-
dunes. In some areas this formation is known to
unconformably overlie the Bathurst Formation instead of the Alexandria Formation.
Schelm Hoek Formation: Comprises mainly unconsolidated modern aeolian sand. The sands are part of currently active
dune fields that reach approximately 6 km inland from the coast.
Late Stone Ageshell middens are often found in the dunes, containing predominantly white sand mussel shells (Donax sera). However, the remains of marine and terrestrial
mammals, stone and bone
artifacts, and occasional pottery pieces are also found.[15][16][17]
Paleontology and archaeology
Fossils are more frequently found in the older formations, although the Alexandria and Salnova formations are the most fossil rich. The most common fossils are of
invertebrates, namely of
marinegastropods and
bivalves, and
trace fossils left such as of burrows left by invertebrates. Vertebrate
trackways of birds and modern humans are known from the Nahoon Formation.[18]
The Nahoon and Schelm Hoek Formations are known for their archeological
artefacts, including modern human trackways in the case of the Nahoon Formation. Both these formations have yielded
stone tools.
Shell middens and evidence of for small, coastal human settlements are known from the Schelm Hoek Formation.[19][20][21]
References
^Roberts, D. L., Botha, G. A., Maud, R. R., Pether, J., and Johnson, M. R. (2006). Coastal cenozoic deposits. The geology of South Africa. Johannesburg/Pretoria: Geological Society of South Africa/Council for Geoscience, 605-628.
^Dingle, R.V., Siesser, W.G. and Newton, A.R., 1983. Mesozoic and Tertiary geology of southern Africa. Rotterdam: Balkema.
^Partridge, R.R., 1987. Geomorphic evolution of southern Africa since the Mesozoic. South African Journal of Geology, 90(2), pp.179-208.
^Roberts, D.L., Botha, G.A., Maud, R.R., Pether, J. and Johnson, M.R., 2006. Coastal cenozoic deposits. The geology of South Africa. Johannesburg/Pretoria: Geological Society of South Africa/Council for Geoscience, pp.605-628.
^Le Roux, F.G., 1988. The Alexandria, Nanaga and Salnova Formations redefined and their stratigraphic positions in the Algoa Group. Geoconl {ress' 88. Ext. Abstr. 22nd Earth Science Conl {ress, Geo/. Soc. S. Afr, pp.363-366.
^Le Roux, F.G., 1989. Lithostratigraphy of the Nahoon Formation (Algoa Group) (No. 9). Republic of South Africa, Department of Mineral and Energy Affairs, Geological Survey.
^Partridge, T.C., Avery, D.M., Botha, G.A., Brink, J.S., Deacon, J., Herbert, R.S., Maud, R.R., Scholtz, A., Scott, L., Talma, A.S. and Vogel, J.C., 1990. Late pleistocene and holocene climatic-change in Southern Africa. South African Journal of Science, 86(7-10), pp.302-306.
^Roberts, David L. (2008-12-03). "Last Interglacial Hominid and Associated Vertebrate Fossil Trackways in Coastal Eolianites, South Africa". Ichnos. 15 (3–4): 190–207.
doi:
10.1080/10420940802470482.
ISSN1042-0940.
^Roberts, D. L., Botha, G. A., Maud, R. R., Pether, J., and Johnson, M. R. (2006). Coastal cenozoic deposits. The geology of South Africa. Johannesburg/Pretoria: Geological Society of South Africa/Council for Geoscience, 605-628.
^Illenberger, W.K., 1992. Lithostratigraphy of the Schelm Hoek formation(Algoa group). Lithostratigraphic series.
^Roberts, David L. (2008-12-03). "Last Interglacial Hominid and Associated Vertebrate Fossil Trackways in Coastal Eolianites, South Africa". Ichnos. 15 (3–4): 190–207.
doi:
10.1080/10420940802470482.
ISSN1042-0940.
^Roberts, D. L., Botha, G. A., Maud, R. R., Pether, J., and Johnson, M. R. (2006). Coastal cenozoic deposits. The geology of South Africa. Johannesburg/Pretoria: Geological Society of South Africa/Council for Geoscience, 605-628.