Living Africa

Habitat, Resources and Global Change


Theme Co-ordinators:
Marian Tredoux (UFS), John Compton (UCT), Oliver Bens (GFZ)

Under investigation:

  • Ecosystems and Climate Change
  • Soil systems and Land Use
  • Mineral resources, mining and the environment

Benefits:

  • Ecosystems and climate change - past archives and present-day records
  • Soil systems and land use - linking human habitat with the dynamics of the solid earth
  • Mineral resources, mining and the environment – backbone to the welfare of South Africa.


Projects:

3.1a Ecosystems and Climate change Natural gas generation, migration and sequestration – implications for greenhouse gas budgets on continental slopes, South Africa
3.1b Ecosystems and Climate change Slope Deposits and (Paleo)Soils as Geoarchives to Reconstruct Late Quarternary Environment of Southern Africa
3.1c Present and past lake ecosystems in Southern Africa – natural variability and anthropogenic impact
3.1d Understanding past episodes of global change: the Late Ordovician record in southern Africa
3.2a Multi-scale assessment of the hydrological situation in the around Sutherland and the Western Karoo
3.2b Vulnerability of the critical zone of central South Africa. (8 sub-projects)
3.3a Natural Resources of Africa: The Platinum Value Chain (Platinum VC)

 


Project Descriptions



Project 3.1a:

Ecosystems and Climate change Natural gas generation, migration and sequestration – implications for greenhouse gas budgets on continental slopes, South Africa

Participants (* indicates project coordinator)

GFZ Potsdam (GFZ), Germany Rolando di Primio*
BrianHorsfield                                                     
Zahie Anka
University of Cape Town (UCT), AEON (SA) John Compton*
George Smith
Maarten de Wit
Petroleum Agency of South Africa (PASA) David van der Spuy
David Broad
University of Western Cape (UWC), SA Reginald Domoney/Paul Carey
DeBeers Marine (SA) Mike Williamson
Neil Fraser
PetroSA Jeff Aldrich

Summary

The world’s largest storage of carbon is in sedimentary rocks but the largest magnitudes of fluxes in the global carbon cycle are usually not considered to involve the rock pool directly over short time periods. On geological time scales, however, deposition and burial of organic matter plays a crucial role for hydrocarbon generation and migration in the form of oil and natural gas. Such hydrocarbon fluxes, especially when they reach the surface, contributes to the short-term and long-term fluxes of the carbon-cycle and may even play a role in climate history. Sedimentary basins contains most of these hydrocarbon accumulations and understanding the geological processes behind hydrocarbon generation, accumulation and leakage is not only of economic importance but importantly helps also to assess the contribution of greenhouse gas emissions from underlying thermal sources and the deep biosphere into the hydrosphere and atmosphere.

This project aims to study source-transport-sequestrations systems within sedimentary basins of different settings from the present day back in geological time through the Cenozoic to the Jurassic. This time range is needed to cover all quantitatively significant processes of the carbon-cycle with respect to resources as well as climate.

The input and integration of various disciplines and methods is needed to unravel the relevant processes behind a basin’s development. On the one hand GFZ will contribute with advanced basin modelling techniques and geochemical analytics. On the other hand integration of the findings from lithospheric, sedimentological, (paleo-) environmental, (paleo-) oceanographic and (paleo-) climate studies are needed as a backbone for the modelling approach.

In addition, the teaching of organic geochemistry and basin modelling is an essential part of our contribution to capacity building for South Africa. The initial 3-day short course within Inkaba-phase I for the South African Petroleum Studies Program of the Universities of the Western Cape, University of Cape Town and Stellenbosch University, will be continued on a bi-annual basis.

Subproject 3.1a Associate Project   

GASHsa - ShaleGas in SA   -   Project Leader : Prof. Dr Brian Horsfield 
http://www.gfzpotsdam.de/portal/gfz/Struktur/Departments/Department+4/sec43
 

 

Back to Project List


Project 3.1b:

Ecosystems and Climate change Slope Deposits and (Paleo)Soils as Geoarchives to Reconstruct Late Quarternary Environment of Southern Africa

Participants (* indicates project coordinator)

TU München (Germany) Joerg Voelkel*
LMU München (Germany) Alexander Altenbach
Universität Regensburg (Germany) Klaus Heine*
Nordic Laboratory for Luminescence Dating, University of Aarhus (Denmark) Andrew Murray
GeoForschungsZentrum (GFZ) Potsdam (Germany) Hermann Kaufmann
Sabine Chabrillat
Oliver Bens
University of the Free State (UFS), Bloemfontein (SA) Louis Scott
Chris Gauert
University of the Witwatersrand (UW) Stefan Grab
Desert Research Foundation of Namibia (Windhoek - Gobabeb), Namibia Joh Henschel
Council for Geosciences SA (Pietermaritzburg), SA Greg Botha

Summary

Although it is clear that large, rapid temperature changes have occurred during the last glacial-interglacial cycle and the Holocene in southern Africa, we have only limited, and often imprecise, knowledge of how the major moisture-bearing atmospheric circulation systems have reacted to these changes, and how regional environments have been impacted. Precipitation records are often restricted in space and time. Using slope deposits and soils as palaeoclimatic geoarchives we will overcome these constraints. The project will employ state-of-the-art geoscience methodology to document and interpret the record of precipitation changes of the late Quaternary, including the shifting of the summer and winter rain belts, the chronology of catastrophic floods (geohazards), the wind intensity and direction, and the role climatic factors may have played for prehistoric cultures. The program will generate space and time transgressive models of slope deposit formation and soil development and identify key parameters controlling slope processes. These results will provide a solid base for evaluation and assessment of precipitation conditions and erosion/sedimentation processes for southern Africa under global warming conditions.


Back to Project List


Project 3.1c:

Present and past lake ecosystems in Southern Africa – natural variability and anthropogenic impact

Participants (* indicates project coordinator)

GeoForschungsZentrum (GFZ) Potsdam (Germany) Achim Brauer*
Sabine Chabrillat
Brian Horsfield
Jens Kallmeyer
Kai Mangelsdorf
Hedwig Oberhänsli
Birgit Plessen
Georg Schettler
Heinz Wilkes*
Marine Paläoklimaforschung, Universität Kiel (Germany) Ralph Schneider
University of the Witwatersrand (UW), SA Tim Partridge
University of the Free State (UFS), SA Louis Scott
University of KwaZulu Natal (UKZN), SA Michael Watkeys*
R Uken
H. Cawthra
University of Botswana (UB), Botswana Zibizani Bagai

Summary

This project consists of two integral elements, firstly the analysis of high resolution lacustrine sedimentary records with respect to environmental and climatic variability in Southern Africa during the late Quaternary and secondly the study of biogeochemical and geomicrobiological processes in the present day lakes and their sediments. The results will enhance our understanding of the relationship between parameters measured in lake sediments from the southern part of Africa and marine sediments from the SW Indian Ocean and climate variability over the Indian ocean and adjacent land masses. We will use the archives to infer on variations in the “Southern Oscillation” modulated by the pressure distribution over SE Asia. The biogeochemical and geomicrobiological investigation will provide unique insights into saline lakes and their sediments which are not very well studied on the ecosystem level today. The results will improve our knowledge about adaptation of life to extreme environments and carbon cycling under variable environmental conditions.


Back to Project List


Project 3.1d:

Understanding past episodes of global change: the Late Ordovician record in southern Africa

Participants (* indicates project coordinator)

GeoForschungsZentrum (GFZ) Potsdam (Germany) R.L. Romer*
University of Cape Town (UCT), SA Kerstin Drost
John Rogers*
Maarten de Wit
Museum für Mineralogie und Geologie Staatliche Naturhistorische Sammlungen Dresden (SNSD), Germany Ulf Linnemann

Summary

During the late Ordovician, huge volumes of sandstone were deposited in rift and thermal subsidence basins that developed when the Gondwana supercontinent was extended and began to break-up along its northern and southern margins. These siliciclastic sediments are very unusual because of their unprecedented volume and their unusual maturity. In South Africa, the famous Pettijon called these (the Table Mountian Group) “the biggest pile of sand I have ever seen”. The mature sandstone sediments in turn are abrubtly covered by glacial deposits (tillites) that locally reach a thickness of more than 150 m. The origin and regional extent of this short-lived glaciation is not understood.

This subproject aims at a detailed geochemical and isotope-geochemical investigation of exemplary late Ordovician sedimentary sequences in Southern Africa, in combination with U-Pb LA-ICP-MS age determinations on detrital zircons. The results will allow us to trace the provenance of these Ordovician sandstones that occur across all of Gondwana and Gondwana-derived terrains. This work will improve the reconstruction of pre-drift Gondwana margins; and it should provide a better estimate of how Gondwana’s internal Neoproterozoic mountain ranges were exhumed and eroded, and what effects these processes had on the rapid evolution of the biosphere during the early Palaeozoic.

A detailed investigation of the glacial layers capping the will allow to identify the nature and extent of environmental changes (gradual versus catastrophic) that led to one of the major shortlived glaciations in Earth’s history (e.g. as opposed to the extended Neoproterozoic ‘snowball Earth’ or cryogenic period that preceeded it) and was accompanied by a severe episode of mass extinctions. This is particularly enigmatic because the late Ordovician paleopole and and related extensive icecap were centred between southern Algeria and southern Chad (e.g. north-central Africa), yet the contemporaneous Pakhuis Formation glacial deposits of southern South Africa ( and adjacent southern South America) were deposited at 30 degrees latitude, global regions ‘normally’ free of ice.

A modern investigation of the late Ordovician sandstones and the overlying glacial siliciclastics in southern African that represent the southern margin of Gondwana, is especially crucial and timely to link with the recently major advances in understanding of their stratigraphic equivalents in terranes that represent fragments rifted off the northern margin of Gondwana (e.g. Saxo-Thuringia, Bohemia, Meguma terranes). This approach will enable. for the first time, a realistic analyses and comparison of contemporanoues tectonically active margins of Gondwana separated from each other by up to 10,000 km. Thus, the approach will provide a more robust modelling platform for palaeo-environmental and palaeo-climate changes on a truly global scale in the period 400 to 500 million years ago.


Back to Project List


Project 3.2a:

Multi-scale assessment of the hydrological situation in the around Sutherland and the Western Karoo

Participants (* indicates project coordinator)

GeoForschungsZentrum (GFZ) Potsdam (Germany) Corinna Kroner*
Juergen Kusche
Franz Barthelmes
Svetozar Petrovic
Rhodes University (RU), SA David Hughes*

Summary

The existence of water and its distribution are of major importance for the environmental wellbeing and economical prosperity of a region. A semi-arid area such as the Western Karoo esp. depends on the availability of groundwater. Therefore it is of essential interest to gain as comprehensive information as possible on the groundwater recharge and discharge in order to allow for an improved water management and to realize an appropriate quality of the water. The goal of this project is to improve the understanding of hydrological processes in this region on different spatial and temporal scales by deploying gravity observations and gravimetric/hydrological modelling. The hydrological effects on the regional scale will be assessed by comparison of satellite gravity data (GRACE) with regional-scale hydrological models combined with the findings and information of the hydrological influences from small scale-investigations derived from observations with a superconducting gravimeter. The results will help for an improved local and regional quantification of hydrological dynamics and thus establish additional means for the management of the valuable resource water.


Back to Project List


Project 3.2b:

Vulnerability of the critical zone of central South Africa (8 sub-projects)

Participants (* indicates project coordinator)

University of the Free State (UFS), SA Chris Gauert
Maitland Seaman
Stephan Steyn
Pieter Taljaard
Marian Tredoux*
Brent Usher
Willem van der Westhuizen
Cornie van Huyssteen
Herman van Schalkwyk
Sue Walker
Agricultural Research Council of SA (ARC) G Zuma-Netshiukhwi
Council for Geoscience SA (CGS - Bellville) L Ngcofe
Luc Chevallier
GeoForschungsZentrum (GFZ) Potsdam (Germany) Hermann Kaufmann*
Samuel Niedermann
Sabine Chabrillat
Oliver Bens*
Corinna Kroner
BGR Hannover (Germany) Hans-Guenter Mylius
H Elsner
Freie Univ-Berlin & Potsdam Institute for Climate Impact Research (Germany) Gerd Bürger
TU München (Germany) Joerg Völkel
University of Bonn (Germany) Wolfgang Britz
Claudia Heidecke
University of Regensburg (Germany) Klaus Heine
Vrije University Amsterdam (Netherlands) Paul Andriessen

Summary

Although a significant amount of data about the geology, soil properties, groundwater flow and chemistry and climate of the central zone of South Africa exist, no comprehensive synthesis of data has been attempted, in order to (1) create baselines for various environmental indicators, (2) assess the degree of vulnerability of the critical zone of this region to global climate change, and (3) to model the physical impacts of predicted trends, and the socio-economic effects of these impacts. This subproject is divided into 8 integrated topics with the common aim to collate the available data, and to generate a coherent set of new data along an E-W line, in order to combine all surface data with modern geological processes, to provide the kind of information which is required for detailed regional climate modelling, and assessment of the effects of predicted change.

The research will be centred on a traverse of 7 research nodes (field labs) across central South Africa, between latitudes 28 and 29 degrees S, from the topographically high and wet (>800 mm.y-1) area in the east, to the low-lying, extremely dry (<200 mm per year) region in the west. In order to extend the climate record back as far as possible, the sites will be situated in close proximity to weather stations for with continuous long-term climate records are available. The line includes an extensive pan field, a major regional ecological barrier, which runs approximately NE-SW across the middle of the traverse. The sites were chosen to provide the maximum possible range in conditions and include completely pristine eco-systems and highly polluted urban areas. Beside urbanization, land-use also include agriculture, recreation, mining and heavy industry. The field work will be complemented by a multi-spectral aerial survey, which will extend the database laterally. On the other side, the field labs will provide physical validation of the spectral interpretation. The combined data will be used by the climatologists, ecologists and agronomists to model the possible effects of various climate change scenarios on the vital factors such as availability of potable water and arable land, biodiversity, flooding and drought. Finally, the impact of the modelled changes on the economic and social future of the region will be considered.

In parallel with the work at the field labs, the neotectonics of the underlying deep crust and upper mantle will be investigated to assess to what extent deep-level geological processes influence surface conditions and processes. The extent and probable surface effects of modern geological activity therefore must be determined. Interaction between climate and the economic geology of the region will also be investigated by research on the diamond-rich gravels in the palaeo-channels of the Orange River.

List of topics and coordinators:

  1. Hydro-vulnerability of the central South African region [Usher, Kroner].

  2. Downscaling climate change scenarios over central South Africa. [Bürger, Steyn].

  3. Crop models to promote sustainable farming practicesalong the critical zone [Walker, Zuma-Netshiukhwi].

  4. A socio-economic analysis of food security [Van Schalwyk, Britz].

  5. Delamination-induced exhumation of the southern African plateau [Haschke and Tredoux].

  6. Extent and probable surface effects of recent geological processes on the regolith in the critical zone: A remote sensing / ground validated investigation of saprolite and river terraces along the Orange River [Gauert & van der Westhuizen, Kaufmann].

  7. An investigation of geomorphological processes determining water availability in semi-arid catchments in central South Africa [Barker, Kaufmann].

  8. Using the field labs as nodes for outreach to stimulate science awareness in rural communities, and to improve the science teaching skills of teachers [Hoffman]


Back to Project List


Project 3.3:

Natural Resources of Africa: The Platinum Value Chain

Participants (* indicates project coordinator)

University of Cape Town (UCT), SA David Reid*
Chris Harris
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Germany Thomas Oberthür
Frank Melcher
GeoForschungsZentrum (GFZ) Potsdam (Germany) Robert Trumbull*
Ilya Veksler
R. Wirth
Universität Hannover  (Germany) Francois Holtz
University of Bonn  (Germany) Christoph Ballhaus
University of the Free State (UFS), SA Marian Tredoux*
Chris Gauert
Council for Mineral Technology of SA (MINTEK) Deshentree Chetty

Summary

This project will combine the complementary resources and expertise of Germany and South Africa to address outstanding current problems in understanding and responsibly managing the huge mineral resources in layered mafic-ultramafic intrusions of the Bushveld type, in particular with respect to the platinum group elements (PGE). The Bushveld Igneous Complex represents a truly mega-scale ore province, hosting enormous resources of ferrous, base and precious metals. South Africa produces about 70% of the world’s platinum from this remarkable intrusion. The sustainable management and use of this resource is clearly of extraordinary economic importance for the nation. Despite of this fact, and the decades of geologic research expended on these deposits, many fundamental aspects of how they formed are still not reliably known. We do not understand, for example, the processes responsible for such extreme enrichment of metals from the mantle, nor what the mechanisms and controlling factors are that govern the final distribution of PGE-rich ores in the host intrusions.

The aim of this subproject is twofold. In the first part (Topic 1), combining the disciplines of economic geology, petrology, geochemistry and mineralogy, we will develop new models for the formation of ore deposits of platinum and related metals in the Bushveld Complex. State-of-the-art analytical, experimental and modelling techniques will be appliled to this unique natural laboratory. This work will address the poorly-understood processes and control parameters of magma genesis and differentiation that lead up to formation of PGE mineralization. We are motivated by recent developments in analytical techniques and in new conceptual models that may succeed where "classical" models have been lacking. The expected outcomes are improved understanding of mineralization processes and the distribution of PGE resources from the mineral to the regional scale. This information is vital not only for optimalization of exploration and effective mining, but also for the post-mining extractive metallurgy.

The second part of the project (Topic 2) is motivated by the extreme rise in the consumption and demand for PGE resources in the technologic age, which creates a need for effective and environmentally responsible resource recovery at the supply end (South Africa), for innovation in technological applications of PGE products for the end user (Germany) and for monitoring the environmental impact of increasingly widespread deployment of PGE by end users, particularly the automotive industry. Planned research topics will include: (i) examination of the post-mining processing chain: currently, when setting up the treatment plants, a number of assumptions are made which are based on the “classical” models, and the base metals are usually used as proxies for the PGE when fine-tuning the plants. The validity of these assumptions needs to be tested; and (ii) the leaching and redistribution of the PGE from ores in the weathering environment, and the assessment of PGE pollution alongside roads with heavy traffic or in city landfill and industrial sites. The results can potentially benefit both the recovery of secondary PGE resources (recycling) as well as minimizing the negative impact of mining, processing and end usage. This aspect of the project will bring together scientists from a wide range of disciplines; a two day forum is planned in year 1 to bring all interested parties together, so that the most recent results can be shared over discipline boundaries, leading to the first truly multi-disciplinary review on the PGE in all aspects of research.

 

Back to Project List

User Logon