Report on Leg 1B of Expedition COCOTOW: Observations at the East Pacific Rise-Siqueiros Transform Fault Intersection.

摘要

The second half of COCOTOW I Expedition concentrated on near-bottom geological and geophysical investigation near 8 deg 17 min N and 104 deg 10 min W. Detailed structural analysis of the East Pacific Rise Siqueiros Transform Fault intersection revealed a complex arrangement of lineations which can be subdivided into three trends: (1) N-S constructional outliers protrude into the deep tow basin from the East Pacific Rise. Normal crustal spreading is occurring well within the northern confines of the survey area; (2) major E-W aligned scarps, along the fracture Zone Median Ridge, have vertical offsets up to 350 fathoms; and (3) The formation of WNW-ESE trending tension gashes reveal a component of extension across the fracture zone. (Author)