A series of both on-bottom seismic refraction experiments using bottom shots and receivers, and seismic refraction profiles using airgun shots and seafloor receivers was conducted on the Mid-Atlantic Ridge in locations where there are extensive outcrops of mantle peridotites. The objectives of this project are to: (1) determine the depth extend of ultramafic bodies found in the three locations, (2) contrast the velocity structure at these known peridotite outcrops with that found in a typical extrusive-dike-gabbro igneous section formed at a fas spreading ridge, and (3) use the fine-scale velocity structure of these peridotite exposures to identify massive, unfractured outcrops where drilling conditions are good.
