Thesis (PhDGeology)--University of South Australia, 2000.

Thesis (M.S. - Geosciences)--University of Arizona. / Includes bibliographical references (leaves [26-28]).

The high elevated (ca. 1100 m) continental Kalahari Basin (KB) of southern Africa and the linked lower lying (ca. 400 m) Congo Basin (CB) of central Africa preserve in their interiors extensive sedimentary rock sequences and sediments that represent a unique record of the Phanerozoic geodynamic and climatic evolution of sub-Saharan Africa. In this thesis, field observations and new borehole data from the Democratic Republic of Congo (DRC) and Botswana are integrated with new paleontology and geochronology to present a substantially revised stratigraphy for the CB, and south-central Africa in general. This work also introduces a new multiphase model for the subsidence and uplift history of the CB, and improves correlations with the Cape-Karoo Basin (CKB) of South Africa and the Paraná Basin (PB) of south-east Brazil. Four deep boreholes, each between 2 and 4.5 km deep, drilled in the centre of the CB in the 1950’s and 1970’s are re-examined together with the colonial literature (in French) and available seismic data. This stratigraphic and basin analysis is complemented with new U-Pb dates of detrital zircons from core-samples of two of the boreholes (Samba and Dekese), as well as from samples collected during field work in the Kwango region of the south-west DRC. This work, for the first time, constrains the maximum ages and source provenances of the successions in the CB. Following the Pan African orogens (ca. 650-530 Ma), extensive sequences of red beds were deposited by regional paleocurrents to the south. These are now best preserved (1 km thick) along the West Congo, Oubanguides, and Lufilian Belts surrounding the CB. Overlying a hiatus that represents most of the early-Paleozoic, is a 1 to 3 km thick succession of easterly derived glacial, and then continental sequences of the Karoo Supergroup. This succession records the first main episode of subsidence [10-15 m/Ma], interrupted by a phase of uplift that is likely related to far-field intracontinental deformation within Gondwana supercontinent during the Variscan and Cape Fold orogenies (ca. 250-330 Ma) at its peripheries. Detrital zircons from the lower Karoo diamictites are dated at 1.85-2.05 Ga and 1.37- 1.42 Ga, and thus sourced from Paleoproterozoic (Eburnean) and mid-Mesoproterozoic (Kibaran type-I) basement rocks in Uganda and Tanzania. Zircons from all the other successions in the CB date predominantly at 950-1050 Ma and 500-800 Ma. These are derived from sediment recycling of late-Mesoproterozoic (Kibaran type-II) and late- Neoproterozoic (Pan African) sources in the Central African Republic (CAR) and Chad. A distinct unconformity across the Karoo Supergroup in the CB is overlain by 500- 1000 m Jurassic-Cretaceous sequences, here named the Congo Supergroup. During initial rapid subsidence [10-50 m/Ma], late-Jurassic (Kimmeridgian) shallow marine to continental sedimentation attests to a short transgression of proto-Indian Ocean waters into the northern CB (at 160 m above present day sea-level), succeeded by widespread deposition of aeolian dunes that extend from the southern CB to the PB in South America. The youngest zircons from these aeolian sediments in the CB date at 190 Ma and 240-290 Ma, and most likely indicate the influence of extensive silicic volcanic ash derived from the proto-Andes along the south-western margin of Gondwana. Two superimposed mid-Cretaceous (Albian-Cenomanian) lacustrine sequences in the central CB record a succeeding, slower [10-15 m/Ma], phase of basin subsidence during the opening of the South Atlantic (ca. 85-135 Ma). These Cretaceous sequences are in turn truncated by another regional peneplanation surface covered by Cenozoic (Eocene) silcretized sands and alluviums of the Kalahari Group, only 50-250 m thick in the centre of the CB. Southward, on top of the Kalahari Plateau in the central desert region of north-west Botswana, new boreholes intercepted laterally equivalent condensed lacustrine carbonates and calcretes (20-50 m thick) covered by sands. These terrestrial sequences are key archives of late-Mesozoic – Cenozoic paleo-climate changes, yet they remain stratigraphically unresolved. This new analysis of the Phanerozoic continental basins of south-central Africa and their equivalents in South America, opens a fresh continental-scale window into how West Gondwana break-up and concomitant epeirogenic uplifts of Kalahari (>2 km) and Congo (>200 m) are linked to interactions between the lithosphere and mantle geodynamics, and how these processes likely affected global climate changes.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Geological Sciences and Environmental Studies, 2007. / Includes bibliographical references (leaves 308-314).

Thesis (Ph.D.)--University of Western Australia, 2006.

In this thesis, I present new results based on 2D multi-channel seismic data of the Song Hong-Yinggehai and Qiongdongnan Basins, geochemical data derived from ODP Site 1148, and sediment provenance analysis of modern sediment and Cenozoic sedimentary rocks collected along the Red River system. The Song Hong-Yinggehai Basin started opening after ~50 Ma but strong subsidence, triggered by motion on the Red River Fault, only occurred after ~34 Ma.  This process was followed by thermal subsidence after ~21 Ma.  In contrast, the formation the Qiongdongnan Basin is believed to be related to the development of the northern rifted margin of the South China Sea. Sediment budget estimates, coupled with geochemical data show that chemical weathering gradually decreased after ~25 Ma, while physical erosion became stronger.  These data also suggest a period of the monsoon enhancement (~15-10 Ma), although with a likely initial East Asia monsoon strengthening ~23 Ma. U-Pb zircon dating coupled with Hf isotopes, muscovite Ar-Ar dating, bulk sediment Nd isotope and heavy mineral analysis allow me to draw the following points: (1) if the headwaters of the modern Yangtze, Mekong and Salween Rivers were ever connected to the palaeo-Red River then they were disconnected from the Red River no later than the Middle Miocene; (2) The palaeo-Red River flowed northeast of the Day Nui Con Voi during the Miocene and did not flow via Lao Cai and southwest of the range as it is observed today; (3) the Yangtze Craton and the Songpan Garze Block are the most important source regions to the Red River; (4) apart from the main Red River trunk, the Lo River is the most important sediment contributor to the Red River system, while the Da River is only a minor contributor.

Thesis (doctoral)--Freie Universität Berlin, 2004. / "April 2004"--P. [2] of cover. Lebenslauf. Includes bibliographical references (p. 182-[199]). Also available on the World Wide Web.

The formation and evolution of sedimentary basins are best understood within the context of prevailing tectonic conditions. This dissertation presents an integrated geologic and geophysical study of the southeast Caribbean–northeast South American margin which is characterized by a 300-km-long curved transition from subduction to strike-slip plate boundary interaction. Tomography models are generated to image the geometry and orientation of the subducting slab and associated upper mantle structures, and integrated with observations made from gravity, magnetic and seismicity data. The plate boundary interaction changes laterally from: (1) direct subduction where oceanic South American lithosphere dips towards the west at up to 65° beneath the Caribbean plate; to (2) collision where South American transitional-continental type lithosphere dips 44°–24° beneath the Caribbean plate; to (3) east-west oriented strike-slip interaction where the slab is detached from the South American continent. A tectonostratigraphic framework based on the interpretation of ~10,000 km of 2-D seismic and abundant well data is used to study the evolution of the structures and basin fill of the margin. The basins are characterized by composite and superimposed structural styles which differ from basins formed in pure strike-slip or convergent margins. A NW–SE oriented tear fault aligned with the South American continent-ocean-boundary defines the boundary between different contractional styles in the sedimentary succession of the subduction and collision provinces. An examination of bathymetric conditions and the upper Pleistocene succession of the continental shelf suggest a bimodal sediment transport process, linked to shoreline changes. Current-driven, strike-parallel sediment distribution systems dominate during highstand, generating unique shelf-bound channels and fills. Lowstand across the area is characterized by dip-directed, sediment distribution systems with SW–NE oriented channels that direct sediments to the shelf edge and deep basin environments. The results of this study illustrate that plate boundary conditions and associated lithospheric arrangement at depth, play a significant role in influencing the form of shallow structures, basins and surface geomorphology. Crustal-scale structures; influenced by deeper lithospheric-scale configuration, act over longer time-scales to create and deform depocenters; while sea-level stand exerts significant control on the timing and location of sedimentation over shorter time periods. / text

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 152 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 62-64).

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