|27 June 2008
GSA Release No. 08-31
Director - GSA Communications & Marketing
The Geologic Forces that Shaped Africa
A new publication by the Geological Society of America outlines the topographic evolution of the dynamic African continent, illustrating how its unique geomorphic history reflects its distinctive tectonics. Authors Kevin Burke of the University of Houston and Yanni Gunnell of University Denis Diderot Paris 7 detail this history, noting that "the geomorphologic evolution of Africa during the past 200 million years has been quite unlike that of any of Earth's other continents."
This striking hardcover book is illustrated with 33 figures detailing the development of Africa over the past 180 million years. Burke and Gunnell draw on a variety of sources, mostly in English and French, to explore an array of topics, such as landforms, bauxites and laterites, fission-track studies, climatic changes, volcanic rock distribution, hotspots, mantle plumes, and rifts, as well as deep and shallow mantle geophysics, ocean floor evolution, continental flooding, and offshore sediment deposition. Two episodes of continental breakup and the initiation of the formation of ocean floor were followed by erosion that reduced the continent to a low-elevation and low-relief African Surface by Late Cretaceous times.
Burke and Gunnell conclude that Africa’s present-day distinctive basin and swell topography developed during the past 30 million years as the low-lying African Surface responded to newly-developed shallow mantle convection and climate changed radically after the Antarctic ice sheet first formed. Northern Hemisphere glaciation and related Sahara initiation 3 million years ago triggered Africa’s most recent great geomorphological changes.
Individual copies of the volume may be purchased through the Geological Society of America online bookstore http://www.geosociety.org/bookstore/default.asp?oID=0&catID=8&pID=MWR201 or by contacting GSA Sales and Service, .
Book editors of earth science journals/publications may request a review copy by contacting Jeanette Hammann, .
The African Erosion Surface: A Continental-Scale Synthesis of Geomorphology, Tectonics, and Environmental Change over the Past 180 Million Years
Kevin Burke and Yanni Gunnell
Geological Society of America Memoir 201
2008, 66 pages, US$45.00, GSA Member price US$31.50