Summary

Description

The depositional systems are provided here with permission of W.E. Galloway and the Jackson School of Geosciences, University of Texas at Austin, http://www.ig.utexas.edu/research/projects/gbds/gbds.htm. For more information and discussion of the various depositional systems the user is referred to Galloway and others, 2000, Cenozoic depositional history of the Gulf of Mexico basin: American Association of Petroleum Geologists Bulletin, v. 84, p, 1743-1774. The Lower Miocene is divided into an earlier (Lower Miocene 1) and later (Lower Miocene 2) depositional system separated by a prominent transgressive marine shale tongue containing the Marginulina A fauna (Galloway and others, 2000). The Middle Miocene is broken into a lower H system and an overlying I system based on basin center seismic sequences. It should be noted that although differing in detail, the onshore portions of the Lower Miocene depositional systems are very similar as are the onshore parts of the Middle Miocene systems. Each of the depositional system layers also contains the trace of the relict shelf margin break of the underlying system. The trace of the shelf margin break for the subject system is contained in a separate layer, as are the labeling symbols and outlines of the various depositional environments. These datasets contain basic data and interpretations developed and compiled by the U.S. Geological Survey's Framework Studies and Assessment of the Gulf Coast Project. Other major sources of data include publicly available information from state agencies as well as publications of the U.S. Geological Survey and other scientific organizations. In cases where company proprietary data were used to produce various derivatives such as contour surfaces, the source is cited but the data are not displayed.