Lawrence D. Meckel, 2013. "Shelf Margin Deltas: The Key to BIG Reserves", Shelf Margin Deltas and Linked Down Slope Petroleum Systems–Global Significance and Future Exploration Potential, Harry H. Roberts, Norman C. Rosen, Richard H. Fillon, John B. Anderson
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Deltas that cross the shelf, either by prograding at a high stand or due to sea level drop during a low stand, produce distinctive depocenters which are important exploration targets at the shelf edge. The deltas become unstable as they try to prograde into deep water and deposit units that are geologically unique and very different from their counterparts that prograde across a stable shelf. These unstable deltas produce a variety of contemporaneous (early) structures including growth and glide plane faults numerous associated faults, diapirs, and gravity slides. The growth faults result in a greatly expanded reservoir section. These downdip delta systems are uncoupled from their updip feeder systems by these major growth faults and are typically encased in highstand deep water shales thus becoming excellent exploration targets: an over-pressured section, early structures, expanded reservoirs, and good seals.
Virtually all of the largest plays (the multiple TCF type) for the onshore and shelf parts of the Gulf of Mexico during the last 30 years have been in these shelf-margin delta systems. Examples from the Tuscaloosa, Wilcox, Yegua, Vicksburg, Frio, and offshore Miocene are examples. These plays are not unique to the Gulf Basin but will occur in any basin where deltas reach the shelf margin and prograde into deep water. The successes here in the Gulf Basin are simply the beginning of an ongoing worldwide exploration effort in these types of deposits. They provide both useful analogues and important exploration guidelines.