Accomplishment Based Renewal to OCE-0526905: The Geology and Tectonics of Ultraslow Spreading Ridges

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Abstract (Dick 0827825) Intellectual Merit: For over a quarter century the ocean crust has been though to be a simple layered structure comprised of lavas overlying "sheeted dikes", the frozen remains of magma transported along the cracks that form beneath the lavas as the earth tears apart, and finally a thick layer of coarse gabbro rock crystallized in magma chambers beneath the seafloor volcanoes. The goals of this research are to integrate data from detailed rock descriptions of rocks from a new class of mid-ocean ridge spreading center with available local bathymetry from side scan sonar and seafloor video as well as with sea surface magnetics and gravity for three densely sampled regions of the Gakkel and Southwest Indian Ridges (SWIR). The resulting synthesis will draw together, for the first time, a picture of the geology and crustal architecture of representative tectonic end-members for ultraslow spreading centers ridges. The work is important because this relatively recently discovered class of mid-ocean ridge spreading centers, whose geology is presently poorly known, comprise about 30% of the global ridge system. Broader Impacts: The broader impacts of this work will increase the infrastructure for seafloor science by generating a well-documented readily accessible database for samples from ultraslow spreading ridges that will enable additional investigators to identify and obtain key material for new research. It will also train undergraduate geology majors in the identification of seafloor rocks and data from these will form the basis of their senior theses. An innovative laboratory for graduate students in rock identification, description, and integration of seafloor samples into marine geophysical studies will also be developed. The research also forms the basis for public talks on the ocean crust at local schools and at the Woods Hole Oceanographic Institution's public lecture series "Science Made Public" at its exhibit center.