1Texaco, Inc.
2Louisiana
State University
3Tulane University
Abstract: Specialized Depositional Environments of the Continental Shelf- Slope Transition Zone in Miocene to Recent Sediments of the Northern Gulf of Mexico: Exploration Applications in Sequence Stratigraphic and Reservoir Facies Interpretation
Summary
During the earliest phase of sea level rise in a glacioeustatic
cycle, limited accommodation space on the shelf, and the rapid
shoreline transgression associated with massive deglaciation
created a framework within which deltaic deposition was confined to
a narrow zone at the shelf-edge. The relatively steeply reclined
shelf-to-slope transition surface provided the sole depositional
environment offering sufficient accommodation space for the
development of substantial deltaic clinoforms. A mostly emergent
continental shelf during this phase of shelf margin deposition
precluded the generation of winter-chilled shelf water in the
northern Gulf of Mexico. Early-rise stage shelf-edge deltas were
therefore, swept year-round by the tropical Gulf Loop Current.
Importantly, for explorationists, the warm waters of these
early-rise stage deltas were home to distinctive calcareous bank -
turtle grass flat benthic
foraminiferal fauna, which spread from
south Florida across the northern Gulf during the deglacial portion
of each glacioeustatic cycle. In wells with detailed
micropaleontological reports, the recorded presence of this unique
fauna has provided a reliable means of recognizing the position of
the lowstand shelf-to-slope transition.
AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas