AAPG Bulletin; July 2007; v. 91; no. 7;
p. 981-1003; DOI: 10.1306/02060706048
© 2007 American Association of Petroleum Geologists (AAPG)
Mapping sediment-dispersal patterns and associated systems tracts in fourth- and fifth-order sequences using seismic sedimentology: Example from Corpus Christi Bay, Texas
Hongliu Zeng1,
Robert G. Loucks2 and
L. Frank Brown, Jr.3
1 Bureau of Economic Geology, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, University Station, Box X, Austin, Texas 78713-8924; hongliu.zeng{at}beg.utexas.edu
2 Bureau of Economic Geology, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, University Station, Box X, Austin, Texas 78713-8924
3 Bureau of Economic Geology, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, University Station, Box X, Austin, Texas 78713-8924
Hongliu Zeng has been a research scientist for the Bureau of Economic Geology, Jackson School of Geosciences, University of Texas at Austin, since 1997. He earned his B.S. (1982) and M.S. (1985) degrees in geology from the Petroleum University of China and his Ph.D. (1994) in geophysics from the University of Texas at Austin. His research interests include seismic sedimentology, seismic stratigraphy, and special seismic processing as applied to petroleum prospecting. He won the Pratt Memorial Award from AAPG in 2005 for best original article published in the AAPG Bulletin in 2003.
Robert Loucks is a senior research scientist at the Bureau of Economic Geology. He received his B.A. degree from the State University of New York at Binghamton in 1967 and his Ph.D. from the University of Texas at Austin in 1976. His general research interests include carbonate and siliciclastic sequence stratigraphy, depositional systems, diagenesis, and reservoir characterization. Some of his present researches are on Gulf of Mexico sedimentology and reservoir characterization.
L. Frank Brown Jr. is a research professor at the Jackson School of Geosciences at the University of Texas at Austin, where he has conducted research and held administrative positions at the Bureau of Economic Geology for more than 40 years. He is well known in the geoscience community for his many contributions to the field of sequence stratigraphy, a concept he helped define through many lectures, short courses, and articles published in professional journals. Brown has served as an International Distinguished Lecturer for the AAPG and done consulting work throughout the world. He earned his bachelor's degree at Baylor University and his master's degree and doctorate at the University of Wisconsin.
A seismic-sedimentologic study was performed to map fourth- and fifth-order systems tracts in Oligocene (Frio) strata in Corpus Christi Bay, south Texas. Guided by third-order sequence-stratigraphic correlations from seismic and wire-line-log data, we prepared stratal slices from a three-dimensional seismic volume to reveal high-resolution (10-m [33-ft] levels) sediment dispersal patterns and associated systems tracts in a relative geologic-time domain. On average, 1200 m (3940 ft) of sediments were deposited in the third-order lowstand expansion cycle, and at least 16 higher order sequences (fourth- and fifth-order sequences) were recognized. Three types of depositional systems were identified in the Frio stratigraphic section: (1) offshelf lowstand slope fans that are best characterized by submarine channel and levee systems inside and outside incised submarine channels and by fan-shaped sand body geometry; (2) lowstand prograding deltaic systems that are composed of strike-oriented and lobate deltaic sand bodies; and (3) highstand systems that are represented by onshelf barrier, lagoon, and deltaic systems. Higher order sequence development was controlled by the interaction of relative sea level change, sediment supply, and gravity tectonics. The top of sediment ridges was eroded or decapitated during many of the higher order sequences. Sand dispersal patterns are primarily controlled by accommodation resulting from rollover topography associated with growth faulting. Between the boundary fault and the hinge line atop rollover structures, strike-oriented sandstone bodies dominate; within submarine channels and incised valleys and beyond the hinge line to the distal basin, dip-oriented sandstone bodies prevail. Sandstone thickness and dispersal patterns can be predicted by integrating wire-line-log measurements and seismic amplitude patterns.
Copyright © 2009 by American Association of Petroleum Geologists (AAPG)
