Data report: an electron backscatter diffraction study of a gabbroic shear zone, IODP Expedition 304/305

Abstract

Integrated Ocean Drilling Program Expedition 304/305 was designed to investigate the formation and evolution of oceanic core complexes by drilling through the Atlantis Massif oceanic core complex. Characterization of shear zone microstructures from the Atlantis Massif provides information about the area’s deformation history and insight into the formation of oceanic core complexes. Plastic deformation was recognized in only 3% of the recovered core volume. The majority of the shear zones are located in gabbroic lithologies. Using orientation contrast imaging and electron backscatter diffraction, petrofabrics and microstructures were compared between the center and the edge of a gabbroic shear zone collected from IODP Hole U1309D. Analysis of the crystallographic preferred orientation, internal deformation, and grain size variations of feldspar was also performed.