US-France Cooperative Research: Island Fault Blocks in the Northeastern Caribbean

点击翻译按钮获取中文摘要

0340639MannThis three-year U.S.-France cooperative research project involves Paul Mann at the University of Texas at Austin and Jean-Claude Hippolyte at the Universite de Savoie in France. They will perform fault striation studies applied to problems of active tectonics in the northeastern Caribbean. Their previous studies of northwestern and southern Puerto Rico identified fault scarps with earthquake potential in these densely populated coastal regions. In this proposal, they continue fault striation studies on the densely populated islands of Puerto Rico and Vieques (U.S. territory), St. Croix, St. John, St. Thomas, U.S.Virgin Islands, Tortola and Virgin Gorda (British territories). Except for Puerto Rico, these islands form emergent fault blocks framing a major extensional or oblique-slip rifted basin complex underlying the deep-water Anegada Passage.Their specific objectives include: 1) identifying late Cenozoic sedimentary units affected by faulting (offshore, active faults will be used to target likely areas where these faults might extend onshore); 2) finding manmade outcrops in rock quarries and along road cuts that expose striated fault planes; 3) measuring striated fault surfaces to determine the types and orientations of faults present; 4) examining faults in different aged stratigraphic units, establish a fault kinematic history for the opening of the Anegada Passage; and 5) using marine data to better understand the offshore extensions of faults. The U.S. investigator brings to the project expertise in quantitative plate reconstructions, land based geological studies and marine geophysical studies. This is complemented by French expertise on the tectonics of highly curved orogenic belts including the Alps, the Carpathians and the Caribbean. The project will advance understanding of seismicity in this densely populated Caribbean region.The project is jointly supported by the National Science Foundation (NSF) and the Centre National de la Recherche Scientifique (CNRS). NSF will support the expenses of the U.S. investigator and the CNRS covers expenses of the French investigator.