Seismic study of mantle deformation and melt extraction during continental breakup in the ENAM primary site

University Of Texas At Austin, Austin TX

Investigators

Abstract

Continental drift between the eastern United States and northwest Africa about 180 million years ago was a key event in Earth's plate tectonic history. The mechanical and volcanic processes that shaped the continental margins of the eastern U.S. left a record of volcanic crust and deep sedimentary rocks beneath the coastal plain, and offshore in the Atlantic Ocean. This project will examine the deep structure of the passive margin and provide a better understanding of the early tectonic evolution, heat flow, and sediment accumulation along the east coast of the United States. Understanding the geologic history will improve our knowledge of natural resources and ancient submarine landslides that affected the continental slope. The project supports the training of a graduate student. Specifically, the researcher and graduate student will investigate the deep structure and origin of the Blake Spur Magnetic Anomaly, which lies offshore the eastern United States. Seismic data collected during the Eastern North American Margin community experiment will be used to image the crust and upper mantle beneath this magnetic anomaly. A preliminary inspection of the seismic data suggests that seismic waves here can travel through the mantle with a speed that is higher parallel to the magnetic anomaly than perpendicular to it. This form of seismic anisotropy can be used to test whether mantle melt infiltration or stretching of the mantle rock created the rock fabric of the rifted margin.