New Mexico Geological Society Annual Spring Meeting — Abstracts

The Northeast-striking Hogback monocline is a regional, first-order structure that flanks the western margin on the San Juan basin. The San Juan basin has a long history of natural resource production and the geology is well characterized by seismic and well data, making it an attractive prospect for carbon capture and sequestration (CCS) initiatives. However, surficial geologic maps along the Hogback monocline lack detail and do not reliably establish the near-surface geometries of geologic structures that could become migration pathways for injected fluid. Regionally, the Hogback monocline exhibits right-handed stepovers that suggests complexity in the subsurface structural architecture. Models for the development of right-stepping monoclines include oblique slip on the fold-coring fault driven by convergence obliquity, and structural inheritance and reactivation of pre-existing en echelon faults. Preliminary 1:24,000 scale mapping represents a significant update to the published map (1:100,000 scale) and will help characterize the timing, scale, and kinematics of deformation. Here we document joint and fracture orientations along strike in an effort to differentiate between predominantly oblique or normal slip.