Recognition of ancient shoreface deposits. Facies, facies sucessions, and associations. An example from the cretaceous gallup clasticwedge, New México

Abstract

A high-resolution genetic Stratigraphic study was conducted on the four corners area, New Mexico, USA.
Detailed geometric and facial observations made on the Gallup Sandstone allowed to learn about 1. how a Shoreface paleo-depositional environment is incorporated into the stratigraphic record, 2. how it looks like in outcrops, 3. the way time is recorded within it, and 4. dimensions and geometry associated with a shoreface facies tract.
Eight main facies were used to characterize a typical facies succession of the shoreface facies tract. These facies are deposited down slope and reflect coexistence of laterally linked subenvironments and an energy trend that decreases from shallow positions to the deeper ones. These facies are reflected in a vertical profile as a consequence of progradation: a lateral migration of laterally linked subenvironments (observed as shingles) along a depositional profile (observed as clinoforms). Application of seminal observations made by Gressly and Walther are used to exemplify the way of identifying shoreface deposits in the stratigraphic record and their associated time lines. Quantification of the geometric and dimensional attributes give us worthy information to be taken into account in reservoir characterization, modeling and simulation.