Asymmetric spreading across the Juan de Fuca and Gorda rises as obtained from a detailed magnetic survey |
| |
Authors: | Douglas Elvers SP Srivastava Kenneth Potter Joseph Morley Dean Sdidel |
| |
Institution: | National Oceanic and Atmospheric Administration, National Ocean Survey, Marine Surveys and Maps, Marine Geophysics Group, Rockville, Maryland 20852,USA |
| |
Abstract: | Marine magnetic data collected along 37 east-west lines off the Washington and Oregon coast between 42°N and 48°N westward to 144°W have been interpreted. Our interpretation shows that decrease in the offsets of the anomalies across the Surveyor fracture zone and the presence of undisturbed north-south lineations east of it are the result of continuous asymmetric spreading along the Surveyor fracture zone. The survey has delineated the extension of the Blanco fracture zone north-westward to about 133°W. Movement along the Blanco fracture zone was initiated about 15 million years ago. The undisturbed north-south trend of the magnetic anomalies between latitudes 42°N and 48°N and longitudes 133°W and 136°W is interpreted as the interval (22 to 15 my) during which the Juan de Fuca and Gorda rises were one continuous structure. West of 137° the Surveyor, Sedna and three minor fracture zones are mapped. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|