US-Botswana Cooperative Research: Geologic and Geophysical Investigations of the Southwestern Branch of the East African Rift System

Missouri University Of Science And Technology, Rolla MO

Investigators

Abstract

0217831 Atekwana This award supports a three-year collaborative research project between Professor Estella Atekwana, with the Department of Geology and Geophysics at the University of Missouri-Rolla, Professors Motsoptse Modisi and Henri Kampunzu, with the Department of Geology at the University of Botswana, and Professor Stanislas Sebagenzi, with the Department of Geological Sciences in the University of Lubumbashi, in the Democratic Republic of Congo. They will study geologic and tectonic processes during incipient rifting in the East African rift. Rift basins represent the initial stages in the development of passive margins. They are also target areas for sediment accumulation, and these sediments typically contain paleoenvironmental and climatic indicators that can provide important clues to past climate and global change. The seismically active Southwestern Branch of the East African Rift system (EARS) is one of the few places in the world where embryonic rifting can be studied at the beginning of continental extension--before volcanism has occurred. Atekwana and her colleagues will conduct kinematic studies, using a combination of field data and remote sensing data from sites in Botswana, Zambia, and Democratic Republic of Congo, in order to: 1) assess the role of pre-existing structures on rift basin development; 2) determine fault kinematics and direction of the extension; 3) characterize the geometry of the basins, and the underlying crustal and lithospheric structure of the Southwestern Branch; 4) assess current models for fault array development and linkage to form border faults; and 5) develop tectonic and geologic models for the evolution of rifts during the incipient stages of continental extension. The group will also map zones of potential earthquake activity. This project combines Dr. Atekwana's expertise in environmental geophysics and tectonics, with Dr. Kampunzu's expert knowledge of African geology, and that of Dr. Modisi, who is a structural geologist. Dr. Sebagenzi has worked on the extension of the Southwestern rift in the Democratic Republic of Congo and Zambia, and he will contribute field data for those locations as well as his gravity data. The project also includes the participation of a student from the University of Missouri-Rolla as well as a student from the University of Botswana. The results of this project should expand the current knowledge about the geologic and tectonic processes that occur during the earliest stages of continental extension. The maps on potential earthquake activity will provide valuable hazard and mitigation information that can be applied to similar rifts that experience some of the largest and most damaging earthquakes in the world. The maps will also provide a detailed picture of the subsurface geology of this part of the Kalahari, which may be important for mineral resource exploration. The Office of International Science and Engineering and the Division of Earth Sciences are jointly providing support for this project.