R.T. Buffler, 1983. "Structure and Stratigraphy of the Sigsbee Salt Dome Area, Deep South-Central Gulf of Mexico", Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces, A. W. Bally
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The seismic line presented here ((WG-3E) is part of a long regional line (WG-3) that extends across the entire western Gulf of Mexico from the Mexican shelf on the west to the Campeche Escarpment on the east (Figure 1). The line was collected and processed in 1974-75 by the University of Texas Institute for Geophysics (UTIG). See Appendix I for further line information.
Line WG-3 has been used and discussed in several earlier publications. Part of the line was first presented by Ladd et al (1976), who used it in developing a preliminary seismic stratigraphic framework for the thick sedimentary section lying beneath the deep central Gulf of Mexico basin. The entire line was later published as American Association of Petroleum Geologists (AAPG) Seismic Section No. 1 (Watkins et al, 1976). Parts of the line were also included in several later publications (Watkins et al, 1978; Worzel and Burk, 1979).
The western part of the line is presented again here because it (1) shows many interesting and significant structural and stratigraphic features, (2) shows the thick sedimentary section that fills the deep central Gulf basin, (3) shows the six deep-Gulf seismic stratigraphic units defined by UTIG in their "type" area (Shaub et al, in press), and (4) summarizes the geologic history of the deep south-central Gulf of Mexico basin. Discussion of this geologic history can be conveniently subdivided into two major periods, the pre-middle Cretaceous and the post-middle Cretaceous. Rocks representing these two periods are separated by a prominent unconformity and/or reflector that can be followed and mapped throughout the deep Gulf basin and adjacent margins. It has been dated tentatively as middle Cretaceous in age (Buffler et al, 1980, 1981; Addy and Buffler, in press; Shaub et al, in press). Recent DSDP drilling (Leg 77) in the southeastern Gulf indicates that the unconformity in this region is a condensed section that spans the entire Late Cretaceous (Schlager et al, in press). This unconformity and/or reflector is informally designated "MCU" for middle Cretaceous unconformity.