GEOLOGIC MAP OF A PORTION OF CAPE SAN MARTIN/ALDER PEAK/VILLA CREEK/BURRO MOUNTAIN 7.5' QUADRANGLES
In this contribution we propose a new detailed bedrock and structural maps of the Nacimiento block in the vicinity of Cape San Martin, California that feature the complex stratigraphy and geometry of the area. This new proposed geological and structural map highlight new evidence of a complex polyphase deformation unrecognized until now. One of the most significant results from this map is the presence of a 50-75 degrees counter clock-wise re-orientation of structures from the regional orientation. This structural re-orientation is spatially associated with a previously recognized thermal anomaly, in which bedrocks record peak temperatures up to 360 oC compared to the sub-200oC regional background.
The structural maps presented here are used to determine if the thermal anomaly is either: (1) a post subduction high temperature metamorphic overprint or (2) differential uplift associated with a transpressive ridge.