CRUSTAL STRUCTURE IN THE PACIFIC OCEAN NORTH OF SHATSKIY RISE

Abstract

Despite the large amount of deep seismic sounding [DSS] work done in the Northwest Basin, the traverses were set out very unevenly, and mostly cross the central and southwestern parts of the basin, west of the Shatskiy Rise. The only information on the structure of the floor of the basin north of Shatskiy Rise is that provided by the authors' deep seismic sounding on the 29th cruise of the R/V Dmitriy Mendeleyev, in conjunction with seismic investigations from the R/V Glomar Challenger. Calculations and plots of these data indicate that the crustal thickness north of Shatskiy Rise is somewhat greater than that of the crust of ocean basins (6.0 km). The two traverses run at approximately the same distance to the east of the Shatskiy Rise also show a thicker (as much as 10 km) crust. Apparently, this is explained by the antiquity of the ocean floor in this basin, which is consistent with available data on an increase in crustal thickness with age.