Bookshelf tectonics: Rotated crustal blocks within the Sovanco Fracture Zone

Abstract

The 15 kilometer wide Sovanco Fracture Zone is a dextral‐slip transform fault linking the Juan de Fuca and Explorer Ridges in the N.E. Pacific. SEABEAM bathymetry shows that the Sovanco comprises several rhomb‐shaped elevated blocks of oceanic crust bounded by northeast‐ and northwest‐trending lineaments. We hypothesize that the northeast‐trending lineaments are sinistral strike‐slip faults that are reactivated ridge‐parallel normal faults. Both the sinistral block‐bounding faults and the blocks themselves have rotated clockwise about 30 degrees in response to dextral shear within the Sovanco zone.