Cenozoic foraminiferal research

Introduction

Eugene Bergh with nautiloid

The field of invertebrate palaeontology provides crucial substance on evolution. The study of fossil invertebrate animals through geologic time in South Africa includes brachiopods, crinoids and trilobites from the Devonian Bokkeveld Shales, Eurypterids, molluscs, Cretaceous ammonites and Cretaceous to recent microfossils.My research deals mainly with these groups, and in particular more recent Cenozoic-aged invertebrate fossils around the coast of southern Africa.

Foraminifera

Foraminifera (forams for short) are microfossils in a group of protists which produce a single or multiple chambered test (shell) composed of calcium carbonate (CaCO3). Forams have both extinct and extant forms. They are mostly benthic marine, but planktonic and brackish water forms are also common. Fossil foraminiferal assemblages can be used in biostratigraphy to give relative ages to rock strata. As such they are also used in the oil industry. Foraminifera can incorporate seawater constituents (oxygen levels, carbon dioxide levels, elements, isotopes, etc.) into their tests (shells) during their life, and as such, reflect the ocean conditions at that particular point in time. Microfossils can thus very useful in palaeoclimatology and palaeoceanography, aiding in palaeo-environmental reconstruction. They are increasingly being incorporated into climate change studies.

Brachiopod, bivalve and crinoid stem impressions in Devonian aged (410 to 375 million years ago) prodeltaic shales of the Gydo Formation found outside Ceres, Western Cape.

My research on foraminifera from the Namibian outer shelf between Lüderitz and Walvis Bay has revealed an absence of Pleistocene age sediments. The Northern Benguela Region and low temperature bottom waters played a role in the distribution of foraminiferal and ostracodal fauna. The bivalve (mollusc) speciesTellina analogica and benthic foraminifera Ammonia japonica, Elphidium advenum and Lobatula lobatula suggest an estuarine or lagoonal depositional setting for sediments that are now at a depth of more than 200m below sea level.

There is still much room for the advancement of foraminiferal research in southern Africa and generally the rest of Africa. We will expand our collections and provide a valuable baseline for future research.

My research covers material from the Pliocene to the Holocene and focuses on:

  • The contribution of knowledge about past foraminiferal faunas and its associated palaeo-environments.
  • The changes that past climatic shifts and gobal change may have brought upon marine organism distributions around southern Africa.

Research interests

Palaeo-environmental reconstruction and micro-fossil (foraminiferal) assemblage changes through time (past, present and future).

Climate change and the associated changes in marine environments.

Current projects

  • Foraminifera and molluscs from the Namibian outer shelf between Lüderitz and Walvis Bay: implications for palaeo conditions in the Northern Benguela Region of Namibia and sea level change.
  • Pliocene climate change around the western and southern coasts of South Africa.
  • Expanding Iziko’s invertebrate collections to provide a baseline database for future research.

Eugene W. Bergh

M.Sc. (Geology)  University of Cape Town (2012)

Assistant Curator Invertebrate Palaeontology and Geology

Holocene aged (<10 000 years old) foraminifers (white components) amongst black pelletal phosphorite grains and rock fragments found at a depth of more than 200m below sea level off the coast of Luderitz, Namibia. Species in the image include brizalina spathulata, discammina compressa, elphidium advenum and globulumina compressa.

Natural History Department
Iziko South African Museum
PO Box 61
Cape Town 8000
South Africa

 

Tel: +27 21 467 7236
Fax: +27 21 481 3993
Email: ebergh@iziko.org.za

Postgraduate Supervision

Current Students

  • Bright Duze (University of Cape Town; B.Sc. (Hons).; co-supervising with J.S. Compton; 2012). Project: Genesis, stratigraphy and sedimentology of late Cenozoic Namibian off-shore phosphorite deposits.
  • Leilah Gharbaharan (University of Cape Town; B.Sc. (Hons); co-supervising with J.S. Compton; 2012) Project: Geochemistry of Namibian off-shore phosphorites.

Conference Abstracts

Bergh, E.W and Compton, J.S. 2012. A one year post-fire biogeochemical cycling record of a sandstone mountain fynbos ecosystem, South Africa. EGU Abstracts.