THE KOMANDORSKY BASIN AS A PRODUCT OF SPREADING BEHIND A TRANSFORM PLATE BOUNDARY

A long term study of the Komandorsky Basin, in particular by the cruises of R/V Vulkanolog and R/V Dmitry Mendeleev in the summer of 1988, made it possible to describe in detail the main structural features of this marginal basin. Several NE- and N-S-trending spreading axes were detected in the basin in the rear of the transform sector of the Aleutian Arc. Spreading axes are shifted relative to each other along NW-striking transform faults. There is variation in style from north to south along the strike of the spreading axes, and a less-well-defined symmetry compared to that typical of mid-oceanic ridges. The tectonic pattern and heat flow reflect several stages (starting from the Eocene) in the history of the opening of the basin, caused by the changes in the velocity and direction of the relative motion between the Pacific and North American plates.