Unit Affiliation: Marine and Polar Geophysics, Lamont-Doherty Earth Observatory (LDEO)
The project will use the R/V Langseth to collect a 3D seismic reflection box, a dense 2D box, and an OBS offset seismic program over the Deep Galicia Basin to characterize the last stage of continental breakup and seafloor spreading, relate post-rifting subsidence to syn-rifting lithosphere deformation, and learn about the nature of detachment faults.
Ocean basins such as the Atlantic are the end products of a process that begins with continental rifts such as East Africa, passes through a young ocean basin phase thought to be typified by the modern Red Sea, and ends with a broader ocean basin produced over many millions of years by seafloor spreading ? a process by which new ocean floor is created by magmatic and tectonic processes at mid-ocean ridges. Though the process is understood in an general way, the details of its earliest stages are poorly known because the geologic evidence is obscured by overlying sediments, massive volcanism associated with early rifting, and, in most places, thick deposits of salt. Located in the eastern North Atlantic, Galicia, is an exception, where rifting occurred with little volcanism, and there is no overlying salt. For that reason, it is an ideal locality for a strong international team to carry out this three-dimensional seismic reflection survey to image the early-formed geologic structure.