Changes

[[:file:sedimentary-basin-analysis_fig4-40.png|Figure 1]] shows the relationship between 23 fields in the High Island-East Breaks depocenter that produce from the ''Glob alt'' sandstones and the ''Glob alt'' sandstone 200-ft (60-m) isopach. Most of the fields with ''Glob alt'' reservoirs occur around the perimeter of the maximum thickness of net sandstone, near the 200-ft (60-m) isopach. Nearly all of the ''Glob alt'' reservoirs occur basinward of the lowstand middle-to-outer neritic [[Fossil assemblage|biofacies]] boundary [approximately [[length::600 ft]] (200 m) water depth]. Thus, they are downslope from the shelf/slope inflection and below normal wave base where sedimentation is dominated by gravity-flow processes.

[[:file:sedimentary-basin-analysis_fig4-40.png|Figure 1]] shows the relationship between 23 fields in the High Island-East Breaks depocenter that produce from the ''Glob alt'' sandstones and the ''Glob alt'' sandstone 200-ft (60-m) isopach. Most of the fields with ''Glob alt'' reservoirs occur around the perimeter of the maximum thickness of net sandstone, near the 200-ft (60-m) isopach. Nearly all of the ''Glob alt'' reservoirs occur basinward of the lowstand middle-to-outer neritic [[Fossil assemblage|biofacies]] boundary [approximately [[length::600 ft]] (200 m) water depth]. Thus, they are downslope from the shelf/slope inflection and below normal wave base where sedimentation is dominated by gravity-flow processes.

Deposition by gravity-flow processes occurs within physiographic lows.<ref name=ch04r53>Kneller, B., 1995, Beyond the turbidite paradigm: physical models for deposition of turbidites and their implications for reservoir prediction, in Hartley, A. J., Prosser, D. J., eds., Characterization of Deep Marine Clastic Systems: Geological Society, London, Special Publication 94, p. 31–49.</ref><ref name=ch04r5>Kneller, B., and B. McCaffrey, 1995, Modelling the effects of salt-induced topography on deposition from turbidity currents, in C. J. Travis, H. Harrison, M. R. Hudec, B. C. Vendeville, F. J. Peel, and B. F. Perkins, eds., Salt, Sediment and Hydrocarbons: Gulf Coast Section SEPM Sixteenth Annual Research Conference, p. 137–145.</ref> Although each field occurs within a local structural high, most have a major stratigraphic component related to their transport through slope channels and deposition as a gravity-flow deposit within the axis of a salt-withdrawal valley (see [[:file:sedimentary-basin-analysis_fig4-42.png|Figures 3]], [[:file:sedimentary-basin-analysis_fig4-43.png|4]], and [[:file:sedimentary-basin-analysis_fig4-56.png|5]] for the East Breaks 160-161 field). The sands within these valleys were deposited with a slope-parallel orientation. The trapping structure develops after reservoir deposition as the dip-oriented sand bodies are tilted along the flanks of the salt-cored anticlines ([[:file:sedimentary-basin-analysis_fig4-41.png|Figure 2]]). The anticlines continue to grow, and the tilt of the sand body becomes progressively more accentuated as each successive cycle of [[Syncline|synclinal]] fill accumulates and displaces the underlying salt.

Deposition by gravity-flow processes occurs within physiographic lows.<ref name=ch04r53>Kneller, B., 1995, Beyond the turbidite paradigm: physical models for deposition of turbidites and their implications for reservoir prediction, in Hartley, A. J., Prosser, D. J., eds., Characterization of Deep Marine Clastic Systems: Geological Society, London, Special Publication 94, p. 31–49.</ref><ref name=ch04r5>Kneller, B., and B. McCaffrey, 1995, Modelling the effects of salt-induced topography on deposition from turbidity currents, in C. J. Travis, H. Harrison, M. R. Hudec, B. C. Vendeville, F. J. Peel, and B. F. Perkins, eds., Salt, Sediment and Hydrocarbons: Gulf Coast Section SEPM Sixteenth Annual Research Conference, p. 137–145.</ref> Although each field occurs within a local structural high, most have a major stratigraphic component related to their transport through slope channels and deposition as a gravity-flow deposit within the axis of a salt-withdrawal valley (see [[:file:sedimentary-basin-analysis_fig4-42.png|Figures 3]], [[:file:sedimentary-basin-analysis_fig4-43.png|4]], and [[:file:sedimentary-basin-analysis_fig4-56.png|5]] for the East Breaks 160-161 field). The sands within these valleys were deposited with a slope-parallel orientation. The trapping structure develops after reservoir deposition as the [[dip]]-oriented sand bodies are tilted along the flanks of the salt-cored anticlines ([[:file:sedimentary-basin-analysis_fig4-41.png|Figure 2]]). The anticlines continue to grow, and the tilt of the sand body becomes progressively more accentuated as each successive cycle of [[Syncline|synclinal]] fill accumulates and displaces the underlying salt.

This process accelerates during relative lowstand of sea level when the river systems discharge their loads near to or into the heads of the slope valleys.<ref name=ch04r3>Anderson, R., N., Abdulah, K., Sarzalejo, S., Siringan, F., Thomas, M., A., 1996, Late Quaternary sedimentation and high-resolution sequence stratigraphy of the East Texas shelf, in DeBatist, M., Jacobs, P., eds., Geology of Siliciclastic Shelf Seas: Geological Society of London Special Publication 117, p. 94–124.</ref><ref name=ch04r115>Winker, C., D., 1996, High-resolution seismic stratigraphy of a late Pleistocene submarine fan ponded by salt-withdrawal minibasins on the Gulf of Mexico contentental slope: Proceedings, Offshore Technology conference, no. 38, vol. 1, p. 619–628.</ref>

This process accelerates during relative lowstand of sea level when the river systems discharge their loads near to or into the heads of the slope valleys.<ref name=ch04r3>Anderson, R., N., Abdulah, K., Sarzalejo, S., Siringan, F., Thomas, M., A., 1996, Late Quaternary sedimentation and high-resolution sequence stratigraphy of the East Texas shelf, in DeBatist, M., Jacobs, P., eds., Geology of Siliciclastic Shelf Seas: Geological Society of London Special Publication 117, p. 94–124.</ref><ref name=ch04r115>Winker, C., D., 1996, High-resolution seismic stratigraphy of a late Pleistocene submarine fan ponded by salt-withdrawal minibasins on the Gulf of Mexico contentental slope: Proceedings, Offshore Technology conference, no. 38, vol. 1, p. 619–628.</ref>