Geoscience Of Rift Systems

Presents key results of hydrocarbon exploration activities by Amoco and other oil companies during the 1980s and 1990s in a number of rift segments in East Africa. Early chapters give a detailed review of the geological and geophysical data of the main regions explored, and later chapters present ge

Expert petroleum geologists David Roberts and Albert Bally bring you Regional Geology and Tectonics: Phanerozoic Rift Systems and Sedimentary Basins, volume two in a three-volume series covering Phanerozoic regional geology and tectonics. Experience in analyzing and assessing rifts—locations where the Earth’s outer shell and crust have been stretched over time by seismic activity—is critical for you as an exploration geologist in identifying Earth’s most lucrative hydrocarbon locations in which extraction is both efficient and safe. Vast compilations of related industry data present regional seismic lines and cross sections, and summaries of analogue and theoretical models are provided as an essential backdrop to the structure and stratigraphy of various geological settings. Named a 2013 Outstanding Academic Title by the American Library Association's Choice publication A practical reference for petroleum geologists that discusses the importance of rift systems and the structural evolution of the Earth Analyses of active rifts in East Africa, China, Siberia, the Gulf of Suez, and the Russian Arctic provide immediately implementable petroleum exploration applications in regions heavily targeted by oil & gas companies Presents overviews of sequence stratigraphy in rifts and structural controls on clastic and carbonate sedimentation—critical to the exact mapping of the most lucrative hydrocarbon locations by exploration geologists

This work reviews the mechanism of rifting with a focus on pre-existing tectonic weaknesses in pre-rift and/or basement rocks, i.e., on tectonic inheritance. The passive margins that are studied in this book are the Norwegian Continental Shelf, the Eastern North America and the East and West Indian Continental Margins. The continental rifts that have been analysed are the East African Rift System, the Brazilian Continental Rift Systems and the European Cenozoic Rift System. It states how rifts and passive margins serve as valuable locations for hydrocarbon exploration. Tectonic inheritance/heritage examines the influence of pre-existing/pre-rift elements on the geometry, genesis and propagation of rift-related faults. Such elements include anisotropies in the shallow crustal levels, as well as the rheology of the lithosphere. Inheritance greatly influences the architecture of rifted passive margins including the attitude of faults and geometry of horsts, (half-) grabens, transfer zones etc. Inheritance is also a determining factor in the width of rifts and rift shoulder topography.

The seismically and volcanically active East African Rift System is an ideal laboratory for continental break-up processes: it encompasses all stages of rift development. Its northernmost sectors within the Afar volcanic province include failed rifts, nascent sea-floor spreading, and youthful passive continental margins associated with one or more mantle plumes. A number of models have been proposed to explain the success and failure of continental rift zones, but there remains no consensus on how strain localizes to achieve rupture of initially 125-250 km-thick plates, or on the interaction between the plates and asthenospheric processes. This collection of papers provides new structural, stratigraphic, geochemical and geophysical data and numerical models needed to resolve fundamental questions concerning continental break-up and mantle plume processes. The focus is on how mantle melt intrudes and is distributed through the plate, and how this magma intrusion process controls along-axis segmentation and facilitates break-up.

Developments in Geotectonics, 7: East African Rifts focuses on the movements, structure, and behavior of the East African rift system. The selection first offers information on the surface structure and plate tectonics of Afar; tectonic and magmatic significance of volcanism in the Afar depression; and preliminary interpretation of the gravity field of Afar, northeast Ethiopia. Discussions focus on crustal models of Afar based on gravity and seismic data, tectonics, volcanism, geological setting, and crustal extension. The text also elaborates on the gravity survey of the central part of the Ethiopian Rift Valley and an aeromagnetic survey of the Afar triangle of Ethiopia. The book examines the arrangement and development of continental rift zones, East African rift development, and the seismicity of the East African rift system. Topics include earthquake mechanisms, seismicity, and the main categories of rift zones. The manuscript is a dependable reference for readers interested in the East African rifts.

The purpose of the series is to compile and pass on the accumulated knowledge of regional geology that is being lost as generalists with field experience are replaced by specialists with computers. It is designed to appeal to both academic and petroleum geologists. In this third and final part of Volume One, geologists discuss extensional basins including rifts, passive margins, and inverted extensional basins. The chapters have a broadly similar layout, and where appropriate include a section on the petroleum system. They cover non-volcanic and transform passive margins, cratonic basins on pre-Cambrian and Paleozoic basements, and world maps. Annotation ©2012 Book News, Inc., Portland, OR (booknews.com).