Geomorphic Studies of the North Boqueron Bay-Punta Montalva Fault Zones, Puerto Rico

Abstract:

The North Boqueron Bay- Punta Montalva Fault Zone (NBB-PMFZ) is a "capable" fault system that bisects the town of Guanica, Puerto Rico. Geomophic mapping were conducted on hillshades created from LIDAR images from Punta Montalva on the western part of Guanica to Ensenada Las Pardas on the south coast and possibly continues offshore. The purpose was to identify Quaternary deposists and geomorphic features that might suggest Quaternary fault surface rupture. The best geomorphic expression of active faulting is associated with the Punta Montalva fault. Along Punta Montalva fault, linear valleys appear to deflect drainages around bedrock ridges, The main drainages in this area flow primarily to the south and cross the fault roughly perpendicularly and toward the east. The gradients on the drainages change where they cross the Punta Montalva fault. Profiles of these drainages step up to the south across the fault.