Strain localization instability in seafloor spreading centers of the Carmen Basin, southern Gulf of California

Abstract

This study provides new insights into the geological evolution of the Carmen Basin (CB) in the southern Gulf of California (GC). Using high-resolution bathymetry and seismic reflection profiles, we establish a plate-kinematic framework for this oblique-divergent rift system. By analyzing the crustal composition, we investigate the growth of the bounding transform faults and their role in accommodating transtensional shearing. We propose that the mantle upwelling beneath the CB is a northward extension of the East Pacific Rise. The CB consists of three sub-basins with distinct geometries, morphologies, and evolutionary histories. While the southern and central sub-basins are mostly abandoned, the northern sub-basin is currently experiencing seafloor spreading. This is supported by the presence of younger oceanic crust, approximately less than 1.5 Ma, juxtaposed with older oceanic crust that aligns in age with the nearby Guaymas and Farallon basins to the north and south, respectively. Our findings also indicate favorable geological conditions in the CB for the development of hydrothermal systems similar to those observed in the neighboring Guaymas and Pescadero basins in the southern GC.