Interpreting Sedimentary Growth Structures from Well Log and Seismic Data (With Examples)

Growth structures develop when sediments are deposited during tectonic events such as normal and thrust faulting, diapirism, and subsidence. Information about sedimentary and tectonic history can be obtained by analyzing the depths to stratigraphic horizons within growth structures, either from well log or depth-corrected seismic data. For example, differences in depth between correlatable horizons are determined for two wells (^Dgrd), and then plotted versus total depth in the structurally higher well (d). Positive slopes on this graph indicate expanded sedimentary sections, negative slopes are condensed sections, and curves with no slope are environments free of differential tectonic motion. Changes in either sedimentation or tectonic conditions create discontinuities o changes in slope. Thus, the growth plots provide strong constraints on any interpretation. The plot of ^Dgrd versus d helps to distinguish faults from unconformities in well log data, to identify hard to locate sequence boundaries, and to locate stratigraphic miscorrelations, which appear as outlying points from the curve. This method for analyzing sedimentary growth structures can be applied to any tectonic or sedimentary environment and has many applications.

[1]  J. Suppe,et al.  Origin of rollover , 1992 .

[2]  A. Nunns.  Structural restoration of seismic and geologic sections in extensional regimes , 1991 .

[3]  M. Jackson,et al.  A Glossary of Salt Tectonics , 1991 .

[4]  R. Bischke,et al.  Applied Subsurface Geological Mapping , 1990 .

[5]  P. Weimer,et al.  Expansion Profiles and Sequence Stratigraphy: A New Way to Identify Systems Tracts, Sequence Boundaries, and Eustatic Histories , 1990 .

[6]  J. Suppe,et al.  Role of Compaction in Listric Shape of Growth Normal Faults , 1989 .

[7]  R. Groshong.  Half-graben structures: Balanced models of extensional fault-bend folds , 1989 .

[8]  R. R. Cornelius,et al.  Centrifuge modeling of the effects of aggradation and progradation on syndepositional salt structures , 1988 .

[9]  H. A. Vogler,et al.  Exploration for Deep Geopressured Gas: Corsair Trend, Offshore Texas , 1987 .

[10]  F. Pollitz.  Pliocene change in Pacific-plate motion , 1986, Nature.

[11]  James Jackson,et al.  The relationship between the geometry of normal faults and that of the sedimentary layers in their hanging walls , 1986 .

[12]  D. M. Curtis.  Finding Deep Sands in the Gulf Coast Tertiary , 1984 .

[13]  H. Woodbury,et al.  Pliocene and Pleistocene Depocenters, Outer Continental Shelf, Louisiana and Texas , 1973 .

[14]  T. P. Harding.  Newport-Inglewood Trend, California--An Example of Wrenching Style of Deformation , 1973 .

[15]  R. Yeats.  Newport-Inglewood Fault Zone, Los Angeles Basin, California , 1973 .

[16]  J. H. McGowen,et al.  Depositional systems in the Wilcox Group of Texas and their relationship to occurrence of oil and gas , 1967 .

[17]  A. Shaw.  Time in stratigraphy , 1965 .

[18]  E. H. Rainwater.  The Environmental Control of Oil and Gas Occurrence in Terrigenous Clastic Rocks , 1963 .

[19]  Carl E. Thorsen.  Age of Growth Faulting in Southeast Louisiana , 1963 .

[20]  A. Wadsworth.  Percentage of Thinning Chart--New Technique in Subsurface Geology: GEOLOGICAL NOTES , 1953 .