Construction and evolution of slow spreading crust-Atlantis Bank, SWIR

University Of Wyoming, Laramie WY

Investigators

Abstract

Under this award the PIs will investigate the accretionary, structural, and thermal evolution of slow-spreading crust, at the Atlantis Bank oceanic core complex, east of the Atlantis II transform on the Southwest Indian Ridge. They will determine the timing and processes of crustal growth and accretion at very slow spreading ridges, and place constraints on the processes of detachment faulting and uplift of oceanic core complexes, and transverse ridges. They will undertake thermochronometry and geophysical modeling. The thermochronometry will include: 1.Single zircon U/Pb dating to define the emplacement age of gabbro and associated felsic veins found throughout the Atlantis Bank region, and 2. (U-Th)/He chronometry on apatite, zircon and sphene to constrain the timing and rate of cooling/denudation resulting from normal faulting. The geophysical modeling will consist of: 1. Processing new magnetic and gravity data collected in 2002 in order to constrain more accurate plate spreading rates, the timing of past changes in plate motion, and the derivation of a crustal thickness map, and 2. development of both a regional and local 3-D thermal model in order to fully interpret the thermochronometric data.