Changes

==Example==

==Example==

The following figure 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 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 number|1}}.

file:sedimentary-basin-analysis_fig4-41.png|{{figure number|2}}.

file:sedimentary-basin-analysis_fig4-42.png|{{figure number|3}}. Copyright: Armentrout et al. (1991); courtesy Springer-Verlag.

file:sedimentary-basin-analysis_fig4-43.png|{{figure number|4}}See text for explanation.

file:sedimentary-basin-analysis_fig4-56.png|{{figure number|5}}. Copyright: Dow et al. (1990); courtesy Gulf Coast SEPM.

</gallery>

Deposition by gravity-flow processes occurs within physiographic lows.<ref name=ch04r53>Kneller, B., 1995, Beyond the turbidite paradign: 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=ch04r53 /> 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 Figures 4-42, 4-43, and 4-56 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 (Figure 4-41). The anticlines continue to grow, and the tilt of the sand body becomes progressively more accentuated as each successive cycle of synclinal fill accumulates and displaces the underlying salt.

[[: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 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_fig4-42.png|thumb|{{figure number|4-42}}. Copyright: Armentrout et al. (1991); courtesy Springer-Verlag.]]

Deposition by gravity-flow processes occurs within physiographic lows.<ref name=ch04r53>Kneller, B., 1995, Beyond the turbidite paradign: 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=ch04r53 /> 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 synclinal fill accumulates and displaces the underlying salt.

 

[[file:sedimentary-basin-analysis_fig4-43.png|thumb|{{figure number|4-43}}See text for explanation.]]

 

[[file:sedimentary-basin-analysis_fig4-56.png|thumb|{{figure number|4-56}}. Copyright: Dow et al. (1990); courtesy Gulf Coast SEPM.]]

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-withdrawl 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-withdrawl minibasins on the Gulf of Mexico contentental slope: Proceedings, Offshore Technology conference, no. 38, vol. 1, p. 619–628.</ref>