HIGH RESOLUTION INTEGRATED VAIL-GALLOWAY SEQUENCE STRATIGRAPHY OF THE LEONARDIAN BONE SPRING FORMATION, N. DELAWARE BASIN, SOUTHEAST NEW MEXICO

Abstract

Leonardian-aged Bone Spring Formation of the Northern Delaware Basin is investigated using both 3D seismic and petrophysical data. An integrated Vail-Galloway sequence stratigraphic approach was adopted to account for the mixed siliciclastic-carbonate intervals comprising the Bone Spring Formation and their cyclic alternation according to the reciprocal sedimentation model. The optimized lateral and vertical resolution afforded by well-tied seismic data afforded the interpretation of high-resolution sequence stratigraphic frameworks, which in turn provided insights into relative sea level change throughout the Leonardian. Sediment stacking patterns and evolving vertical accommodation as controls on Bone Spring Formation deposition were confirmed, and the reciprocal sedimentation model validated. Inherited topography was further identified as a governing control over observed depositional trends, arising from both extensional deformation and carbonate architecture. Even more, sequence stratigraphic analysis suggests the existence of hitherto undocumented lowstand systems tract (LST) deposits in the upper intervals of the Bone Spring Formation that either fell beneath seismic tuning resolution or were subjected to significant erosional processes such as the passage of mass transport deposits (MTDs) or sediment gravity flows. A dynamic erosional-depositional model positing a mechanism to further explain the absent LST deposits, and which conforms to the overarching reciprocal sedimentation model, is proposed.