CASAVANT, ROBERT R. University of Arizona, Tucson, AZ ([email protected])

ABSTRACT: Basement Tectonics in Southeast New Mexico: Linkages Between Reactivated Ancestral Rocky Mountain Fabrics, Paleozoic Facies Architecture And Hydrocarbon Occurrences

Hydrocarbon exploration and production Within the Delaware Basin Of Southeast New Mexico have historically focused on the Siluro-Devonian, PennsyIvanian and Permian formations of the region. Faulted anticlines, the products of Ancestral Rocky Mountain deformation, seem to be the prevalent trap for oil arid disassociated gas in the Siluro-Devonian reservoirs. However, a regional understanding of the tectonic controls on the facies distribution and reservoir quality for many lower Pennsylvanian and middle Permian siliciclastic reservoirs remains poor. As Such, the role of deepseated basement faulting in the evolution of these major hydrocarbon plays remains largely unrealized.

A recent integrated analysIs of subsurface and geomorphic data sets in southeastern New Mexico suggests that the distribution and structuralstratigraphic architecture of several Morrow and Atoka gas fields and the middle Permian Delaware Sandstone oil play are spatially related to the deepseated basement shear fabrics. Presented is an evolving basement tectonic-stratigraphic model for the region that links the heterogeneous architecture and reservoir quality of a number of major Pennsylvanian and Permian fields to basement fault fabrics. The examples presented illustrate the role of northeast- and north west-trend in g fault fabrics in localizing regions of reactivation and structural inversion in the northern Delaware Basin.

These Iong-lived crustal fabrics undoubtedly played a major role in tile evolution and architecture of the Ancestral Rock), Mountain orogeny. In fact, tile reactivation of long-lived basement faults throughout the southern Cordillera may be the rule, rather than the exception. Recent geomorphic evidence suggests that these basement fabrics have been active during the Late Cenozoic.

AAPG Search and Discovery Article #90915©2000 AAPG Rocky Mountain Section, Albuquerque, New Mexico