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Foraminifera are microscopic single-celled animals which
construct tiny shells, usually about 0.30 to 0.60 mm diameter, that have
provided us with an extremely detailed biostratigraphic record of life on Earth
from the late Precambrian to the present day (about 650 million years).
Foraminifera live in saline environments, mainly in the sea, and often occur in
considerable abundance: a small pinch of sea-floor sediment may contain well
over 5000 foraminifera shells. They also live successfully in artesian borehole
water beneath the Gobi and Sahara deserts, in saline springs in the Namib
Desert, and widely in coastal lakes around the world where there is some saline
influence. At times of particularly high temperatures on Earth, during the
Carboniferous-Permian, the Jurassic-Cretaceous, and the Palaeocene-Eocene and
Miocene periods, some foraminifera inhabiting coral reef lagoon environments
began evolving rapidly, during which time their shell also rapidly increased in
size. The largest foraminifera shells ever are about 10 cm long and shaped like
a cigar. In South Africa the oldest foraminifera are known in black shales and
slates in the Bokkeveld Series (Devonian) and in the Dwyka-Ecca black slates of
the Great Karoo Basin (Permian-Triassic). They are still abundant around South
African shores, but are now greatly changed.
Foraminifera shells are a valuable tool for finding out the
age of marine rocks, or a rock succession, because of their incredible abundance
and diversity through the world’s oceans through time. Therefore statistical
confidence levels on foraminiferal assemblages are far higher than those gained
from vertebrates or dinosaurs, which are researched almost always with a few
incomplete skeletons. Some live in sea-floor environments (benthic
foraminifera): others float at different levels in the world’s oceans (planktic
foraminifera). Foraminifera can tell you precise ages of marine rocks, and the
depositional environment that prevailed at the time those rocks were laid down.
Foraminifera can help you correlate geological events in the Pacific Ocean with
those in the Atlantic Ocean. Foraminifera tell you what the turbulence of the
water was like, whether the water was well-oxygenated or not, whether the
sedimentation rate was fast or slow, whether there is any reworking of
foraminifera from older underlying rocks, and the age of those rocks.
There is a larger literature available for foraminifera
than for any other invertebrate group. This is because they have been widely
used especially in the oil industry, but also in the diamond exploration
industry, around the world since about the 1900’s.
And the reason for such world-wide enthusiasm over such
tiny amimal shells? Despite their small size these microscopic critters are
extraordinarily beautiful. Every day one is finding something new from Africa.
Publications on southern African Foraminifera
Note: These publications are mainly those authored or
co-authored by Ian McMillan.
Dale, D.C. & McMillan, I.K. 1997. Tiny animals, tiny
fossils. Earthyear, the Essential Environmental Guide, Cape Town 16: 98-99.
Dale, D.C. & McMillan, I.K. 1998. Microscopic planktonic
animals off the African coast. Earthyear, the Essential Environmental Guide,
Cape Town 17: 46-47.
Dale, D.C. & McMillan, I.K. 1998. A coast of giant rivers –
the west coast in the time of the dinosaurs. Earthyear, the Essential
Environmental Guide, Cape Town 18: 92-93.
Dale, D.C. & McMillan, I.K. 1999. On the Beach. A Field
Guide to the Late Cainozoic Micropalaeontological History, Saldanha Region,
South Africa. Cameron Design Publishers, Cape Town/ Hirt & Carter Printers,
Cape Town: 1-127.
Dale, D.C. & McMillan, I.K. 1999. How do microscopic fossils
help diamond exploration? Earthyear, the Essential Environmental Guide, Cape
Town 20: 114-115.
Dale, D.C. & McMillan, I.K. 2002. The Pliocene, or how to
correlate sediments using microfossils. Earthyear, the Essential
Environmental Guide, Johannesburg 26: 18-19 (for 2003).
Compton, J.S., Mulabisana, J, & McMillan, I.K. 2002. Origin
and age of phosphorite from the Last Glacial Maximum to Holocene
transgressive succession off the Orange River, South Africa. Marine Geology
Compton, J.S., Wigley, R. & McMillan, I.K. 2004. Late
Cenozoic phosphogenesis on the western shelf of South Africa in the vicinity
of the Cape Canyon. Marine Geology 206: 19-40.
Cooper, J.AG. & McMillan, I.K. 1987. Foraminifera of the
Mngeni estuary, Durban, and their sedimentological significance. South
African Journal of Geology 90 (4): 489-498.
Dale, D.C. & McMillan, I.K. 1997. Late Cretaceous (Early
Turonian to Late Coniacian) hyposaline agglutinating foraminiferal
biostratigraphy of the proximal Orange Basin, western offshore, South
Africa, and southernmost offshore Namibia. Abstract, 3rd. Colloquium on
Stratigraphy and Palaeogeography of the South Atlantic (Yaoundé, Cameroun,
Dale, D.C. & McMillan, I.K. 1998. Mud belt and middle shelf
benthonic and planktonic foraminiferal assemblages compared through the
Holocene successions at two tropical African (Sierra Leone) and two
temperate African (western offshore, South Africa) sites. South African
Journal of Science 94 (7): 319-340. (SASQUA meeting, Cape Town, 1995).
Dale, D.C. & McMillan, I.K. 2000. Pliocene foraminifera and
biostratigraphic correlations of the African continental margin of South
Africa and southern Namibia. Abstract, abstracts volume, 14th African
Colloquium on Micropalaeontology (Luanda, Angola, May 2000).
Dingle, R.V., McMillan, I.K., Majoran, S. & Bisset, L. 2001.
Palaeo-oceanographical implications of Early-Middle Miocene subtropical
ostracods faunas from the continental shelf of the S.E. Atlantic Ocean.
Palaeogeography, Palaeoclimatology, Palaeoecology 173: 43-60.
Franceschini, G., McMillan, I.K. & Compton, J.S. 2005.
Foraminifera of Langebaan salt marsh and their application to the
interpretation of Late Pleistocene depositional environments at Monwabisi,
False Bay coast, South Africa. South African Journal of Geology 108
Gibbons, M.J., Sulaiman, A., Hissman, K., Schauer, J.,
McMillan, I. & Wickens, P.A. 2000. Video observations on the habitat
association of demersal nekton in the midshelf benthic environment off the
Orange River, Namibia. South African Journal of Marine Science 22: 1-7.
Lindsay, P., Mason, T.R., Pillay, S. & Wright, C.I. 1996.
Sedimentology and dynamics of the Mfulozi estuary, north Kwazulu-Natal,
South Africa. South African Journal of Geology 99 (3): 327-336
(Appendix 1 by I.K. McMillan).
Loydell, D.K., McMillan, I.K. & Barron, H. 1988.
Muellerisphaerids from the Llandovery of western mid Wales. Journal of
Micropalaeontology 7 (2): 243-246.
McLachlan, I.R., Brenner, P.W. & McMillan, I.K. 1976. The
stratigraphy and micropalaeontology of the Cretaceous Brenton Formation and
the PB-A/1 well, near Knysna, Cape Province. Transactions of the
Geological Society of South Africa 79 (3): 341-370.
McLachlan, I.R. & McMillan, I.K. 1976. Review and
stratigraphic significance of southern Cape Mesozoic palaeontology.
Transactions of the Geological Society of South Africa 79 (2): 197-212.
McLachlan, I.R. & McMillan, I.K. 1979. Microfaunal
biostratigraphy, chronostratigraphy and history of Mesozoic and Cenozoic
deposits on the coastal margin of South Africa. In: Anderson, A.M. & Van
Biljon, W.J. (eds.), Some Sedimentary Basins and Associated Ore Deposits
of South Africa (Geokongres ’77). Geological Society of South Africa,
Special Publication 6: 161-181.
McLachlan, I.R., McMillan, I.K. & Brenner, P.W. 1976.
Micropalaeontological study of the Cretaceous beds at Mbotyi and Mngazana,
Transkei, South Africa. Transactions of the Geological Society of South
Africa 79 (3): 321-340.
McMillan, I.K. 1974. Recent and Relict Foraminifera from the
Agulhas Bank, South African Continental Margin. Unpublished M.Sc. thesis,
University College of Wales, Aberystwyth: 1-97.
McMillan, I.K. 1986. Cainozoic planktonic and larger
foraminifera distributions around southern Africa and their implications for
past changes of oceanic water temperatures. South African Journal of
Science 82 (2): 66-69.
McMillan, I.K. 1987. Late Quaternary Foraminifera from the
Southern Part of Offshore South West Africa/Namibia. Unpublished Ph.D.
thesis, University College of Wales, Aberystwyth: 1-565.
McMillan, I.K. 1986. Tertiary to Recent foraminifera of the
Algoa Bay area. Institute of Coastal Research, University of Port
Elizabeth, Bulletin 12: 76-80.
McMillan, I.K. 1987. The genus Ammonia Brűnnich, 1772
(Foraminiferida) and its potential for elucidating the later Cenozoic
stratigraphy of South Africa. South African Journal of Science 83
McMillan, I.K. 1989. Victoriella conoidea (Rutten,
1914): a guide foraminifera for the later Aquitanian (Early Miocene) rocks
of southern Africa. South African Journal of Geology 92 (2): 95-101.
McMillan, I.K. 1990. Foraminifera from the Late Pleistocene
(latest Eemian to earliest Weichselian) shelly sands of Cape Town city
centre, South Africa. Annals of the South African Museum 99 (5):
McMillan, I.K. 1990. Foraminiferal biostratigraphy of the
Barremian to Miocene rocks of the Kudu 9A-1, 9A-2 and 9A-3 boreholes.
Communications of the Geological Survey of Namibia 6: 23-29.
McMillan, I.K. 1990. Foraminiferal definition and possible
implications of the major mid-Cretaceous (Albian to Coniacian) hiatuses of
southernmost Africa. Extended abstract, Abstracts Volume, Geocongress ’90
(Cape Town, July 1990), Geological Society of South Africa: 363-366.
McMillan, I.K. 1990. A foraminiferal biostratigraphy and
chronostratigraphy for the Pliocene to Pleistocene upper Algoa Group,
eastern Cape, South Africa. South African Journal of Geology 93 (4):
McMillan, I.K. 1992. Benthonic and planktonic foraminifera
from the Lower Santonian outcrop at Wanderfeld IV, near Bogenfels, southern
Namibia. Géologie Africaine, 11th Colloque Africain de Micropaléontologie
(Libreville, Gabon, May 1991), Elf-Aquitaine Mémoire 13: 412.
McMillan, I.K. 1993. Foraminiferal biostratigraphy, sequence
stratigraphy and interpreted chronostratigraphy of marine Quaternary
sedimentation on the South African continental shelf. South African
Journal of Science 89 (2): 83-89. (SASQUA meeting, Port Elizabeth,
McMillan, I.K. 1997. An Ammonia biostratigraphy for
the Neogene and Quaternary marine and aeolian deposits of the South African
continental shelf and coastline. Abstract, 13th Colloquium of African
Micropalaeontology (Yaoundé, Cameroun, March 1997).
McMillan, I.K. 1997. Quaternary sub-surface stratigraphy of
the Maputaland coastal plain. In: Botha, G.A. (ed.), Maputaland, Focus on
the Quaternary Evolution of the South-East African Coastal Plain, Field
Guide and Abstracts (various Kwazulu-Natal venues, April 1997),
International Union of Quaternary Research, Commission on Quaternary
McMillan, I.K. (and other authors?) 1998. Status of Holocene
foraminifera studies and taxonomic list of foraminifera recognised along the
South African coast and across the continental shelf to upper slope.
Taxonomic Database Blue Book for South Africa, FRD Report, Pretoria: pages?
McMillan, I.K. 2003. The foraminifera of the Late
Valanginian to Hauterivian (Early Cretaceous) Sundays River Formation of the
Algoa Basin, Eastern Cape Province, South Africa. Annals of the South
African Museum 106: 1-274.
McMillan I.K. 2003. Foraminiferally defined biostratigraphic
episodes and sedimentation pattern of the Cretaceous drift succession (Early
Barremian to Late Maastrichtian) in seven basins on the South African and
southern Namibian continental margin. South African Journal of Science 99
McMillan, I.K., Brink, G.J., Broad, D.S. & Maier, J.J. 1997.
Late Mesozoic sedimentary basins off the south coast of South Africa. In:
Selley, R.C. (ed.), Sedimentary Basins of the World 3: African Basins.
Elsevier, Amsterdam: 319-376.
McMillan, I.K. & Stevenson, I.R. 1998. A sedimentation,
tectonic and high-resolution stratigraphic history of the Orange Basin,
western offshore, South Africa and southern Namibia, based on regional and
localised detailed seismic and micropalaeontology studies. Abstract,
abstracts volume, South Atlantic Mesozoic Correlations, IGCP Project 381
(Comodoro Rivadavia, Argentina, November 1998). Asociación Paleontológica
del Golfo San Jorge, Boletín 2 (Special Edition): 21-23.
Ovechkina, M.N., Bylinskaya, M.E. & Uken, R. 2010.
Planktonic foraminiferal assemblage in surface sediments from the Thukela
Shelf, South Africa. African Invertebrates 51 (2): 231-254.
Pegler, E.A. & McMillan, I.K. 1998. Tectonostratigraphic
evolution of the Orange Basin, southwestern Africa. Abstract, Abstracts
volume, Gondwana 10: Stratigraphy of Gondwana (Cape Town, 1998), Journal
of African Earth Sciences 27 (1A): 147.
Rust, I.C., Stear, D.A., Illenberger, W.K., Smuts, W.J. &
McMillan, I.K. 1990. The Alexandria coastal dunefield and its hinterland: a
model for Pleistocene and Neogene palaeogeography of Algoa Bay. In: Heine,
K. (ed.), Palaeoecology of Africa and the Surrounding Islands, A.A.
Balkema, Rotterdam, 21: 61-72.
Stevenson, I.R. & McMillan, I.K. 2004. Incised valley fill
stratigraphy of the Upper Cretaceous succession, proximal Orange Basin,
Atlantic margin of southern Africa. Journal of the Geological Society,
London 161 (2): 185-208.
Toefy, R., Gibbons, M.J. & McMillan, I.K. 2005. The
foraminifera associated with the alga Gelidium pristoides, South
Africa. African Invertebrates (Natal Museum) 46: 1-26.
Toefy, R., McMillan, I.K. & Gibbons, M.J. 2003. The effect
of wave exposure on the foraminifera of Gelidium pristoides.
Journal of the Marine Biology Association, United Kingdom 83 (4):
Valicenti, V.H., Benson, J.M., Petrie, H.S.P., Pringle, A.A.
& McMillan, I.K. 1992. Correlation of depositional sequence tract boundaries
within the Albian 14A sequence, Bredasdorp Basin, South Africa, using
condensed sections. Géologie Africaine, 11th Colloque Africain de
Micropaléontologie (Libreville, Gabon, May 1991), Elf-Aquitaine Mémoire
Wright, C.I., McMillan, I.K. & Mason, T.R. 1990.
Foraminifera and sedimentation patterns in St. Lucia estuary mouth,
Zululand, South Africa. South African Journal of Geology 93 (4):