Comparison and Forward Modeling of Stratigraphic Cyclicity from Two Different Depositional Settings: Implication For Glacioeustatic Influence on Cyclicity Development

Qiucheng (Mike) Ye, William E. Galloway, R. K. Matthews, Cliff Frohlich

The south-central Texas and west Louisiana coastal plains reflect different depositional settings during Miocene time. The Miocene succession in south-central Texas was characterized by strandplain/shore-zone/shelf/slope depositional systems, whereas that in west Louisiana was dominated by fluvial/deltaic/slope systems. In both settings, sediment supply rate was relatively high, which favored development of high-frequency cyclicity.

Despite the different depositional settings, stratigraphic cyclicity (on the time scale of 0.4-2.0 my) is synchronous in both localities. This is suggestive of an external control on the formation of these cycles. Detailed correlation and quantitative testing of the high-frequency cyclicity in the Northern Gulf coast along with comparison with deep ocean oxygen isotopic data as well as a theoretically calculated glacioeustatic sea level curve all suggest that this deterministic factor is orbital forcing. Forward modeling of the cyclicity in both areas using theoretically calculated as well as stratigraphically derived sea level curves further supports this hypothesis.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995