Changes

  | part    = Critical elements of the petroleum system

  | part    = Critical elements of the petroleum system

  | chapter = Sedimentary basin analysis

  | chapter = Sedimentary basin analysis

  | frompg  = 4-1

  | frompg  = 4-24

  | topg    = 4-123

  | topg    = 4-24

  | author  = John M. Armentrout

  | author  = John M. Armentrout

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm

==GOM basin depocenter time intervals==

==GOM basin depocenter time intervals==

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<gallery mode=packed heights=200px widths=200px>

file:sedimentary-basin-analysis_fig4-4.png|{{figure number|1}}Major sand influxes into the northern Gulf of Mexico from Late Cretaceous to recently. After Winker;<ref name=Winker1982>Winker, C. D., Cenozoic shelf margins, northwestern Gulf of Mexico: Gulf Coast Assoc. of Geological Societies Transactions, vol. 32, p. 427-448.</ref> courtesy Gulf Coast Association of Geological Societies.

file:sedimentary-basin-analysis_fig4-4.png|{{figure number|1}}Major sand influxes into the northern Gulf of Mexico from Late Cretaceous to recently. After Winker;<ref name=Winker1982>Winker, C. D., Cenozoic shelf margins, northwestern Gulf of Mexico: Gulf Coast Assoc. of Geological Societies Transactions, vol. 32, p. 427-448.</ref> courtesy Gulf Coast Association of Geological Societies.

file:sedimentary-basin-analysis_fig4-6.png|{{figure number|2}}Tectonic map of the GOM basin. Modified from Buffler;<ref name=Buffler1991>Buffler, R. T., 1991, Early evolution of the Gulf of Mexico basin, in D. Goldthwaite, ed., An introduction to central Gulf Coast geology: New Orleans Gulf Coast Geological Society, p. 1-16.</ref> courtesy New Orleans Geological Society.

file:sedimentary-basin-analysis_fig4-6.png|{{figure number|2}}Tectonic map of the GOM basin. Modified from Buffler;<ref name=Buffler1991>Buffler, R. T., 1991, Early evolution of the Gulf of Mexico basin, in D. Goldthwaite, ed., An introduction to central Gulf Coast geology: New Orleans Gulf Coast Geological Society, p. 1-16.</ref> courtesy New Orleans Geological Society.

</gallery>

</gallery>

In the northern GOM basin, depocenters prograde ([[:file:sedimentary-basin-analysis_fig4-4.png|Figure 1]]) over the transitional crust ([[:file:sedimentary-basin-analysis_fig4-6.png|Figure 2]]) and deform the underlying salt into a complex network of salt-cored anticlines and salt-withdrawal synclines ([[:file:sedimentary-basin-analysis_fig4-8.png|Figures 3]] and [[:file:sedimentary-basin-analysis_fig4-9.png|4]]). Late Neogene depocenters of the Mississippi River, the largest source of sediment to the northern Gulf of Mexico, developed during five time periods from the latest Miocene through Holocene (from Piggott;<ref name=ch04r75>Piggott, N., Pulham, A., 1993, Sedimentation rate as the control on hydrocarbon sourcing, generation, and [[migration]] in the deepwater Gulf of Mexico: Proceedings, Gulf Coast Section SEPM 14th Annual Research conference, p. 179–191.</ref> see also Goldthwaite.<ref name=ch04r38>Goldthwaite, D., 1991, Central Gulf Coast stratigraphy, in Goldthwaite, D., ed., An Introduction to Central Gulf Coast Geology: New Orleans Geological Society, p. 17–30.</ref>) Following are the five depocenter intervals and their time periods.

In the northern GOM basin, [[depocenter]]s [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograde]] ([[:file:sedimentary-basin-analysis_fig4-4.png|Figure 1]]) over the [[transitional crust]] ([[:file:sedimentary-basin-analysis_fig4-6.png|Figure 2]]) and [[Deformation|deform]] the underlying salt into a complex network of salt-cored anticlines and salt-withdrawal synclines ([[:file:sedimentary-basin-analysis_fig4-8.png|Figures 3]] and [[:file:sedimentary-basin-analysis_fig4-9.png|4]]). Late Neogene depocenters of the Mississippi River, the largest source of sediment to the northern Gulf of Mexico, developed during five time periods from the latest Miocene through [[Holocene]] (from Piggott;<ref name=ch04r75>Piggott, N., Pulham, A., 1993, Sedimentation rate as the control on hydrocarbon sourcing, generation, and [[migration]] in the deepwater Gulf of Mexico: Proceedings, Gulf Coast Section SEPM 14th Annual Research conference, p. 179–191.</ref> see also Goldthwaite.<ref name=ch04r38>Goldthwaite, D., 1991, Central Gulf Coast stratigraphy, in Goldthwaite, D., ed., An Introduction to Central Gulf Coast Geology: New Orleans Geological Society, p. 17–30.</ref>) Following are the five depocenter intervals and their time periods.

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<gallery>

<gallery mode=packed heights=200px widths=200px>

file:sedimentary-basin-analysis_fig4-13.png|{{figure number|5}}Paleogeography of the Mississippi River depositional system from approximately 6 Ma to 4 Ma (interval A). After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast Section SEPM.

file:sedimentary-basin-analysis_fig4-13.png|{{figure number|5}}Paleogeography of the Mississippi River depositional system from approximately 6 Ma to 4 Ma (interval A). After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast Section SEPM.

file:sedimentary-basin-analysis_fig4-14.png|{{figure number|6}}Paleogeography from approximately 4 Ma to 3 Ma (interval B). After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast Section SEPM.

file:sedimentary-basin-analysis_fig4-14.png|{{figure number|6}}Paleogeography from approximately 4 Ma to 3 Ma (interval B). After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast Section SEPM.

==Formation of high island-east breaks depocenter==

==Formation of high island-east breaks depocenter==

Between 2.5 and 2.0 Ma, the major northern GOM basin depocenter was focused offshore of western Louisiana and eastern Texas. The westernmost part of this depocenter appears to have been the input area for the ancestral Mississippi River system. The resulting depocenter, the High Island–East Breaks depocenter, has more than [[depth::16,000 ft]] (4875 m) of late Pliocene and early Pleistocene sediments deposited during a succession of highamplitude sea level cycles.

Between 2.5 and 2.0 Ma, the major northern GOM basin [[depocenter]] was focused offshore of western Louisiana and eastern Texas. The westernmost part of this depocenter appears to have been the input area for the ancestral Mississippi River system. The resulting depocenter, the High Island–East Breaks depocenter, has more than [[depth::16,000 ft]] (4875 m) of late Pliocene and early Pleistocene sediments deposited during a succession of highamplitude sea level cycles.

==Timing of petroleum generation==

==Timing of petroleum generation==

<gallery>

<gallery mode=packed heights=300px widths=300px>

file:sedimentary-basin-analysis_fig4-32.png|{{figure number|9}}After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast SEPM.

file:sedimentary-basin-analysis_fig4-32.png|{{figure number|9}}After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast SEPM.

file:sedimentary-basin-analysis_fig4-33.png|{{figure number|10}}After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast SEPM.

file:sedimentary-basin-analysis_fig4-33.png|{{figure number|10}}After Piggott and Pulham.<ref name=ch04r75 /> Copyright: Gulf Coast SEPM.

</gallery>

</gallery>

Each of the isopach maps in this section is annotated with the area of active petroleum generation and migration. These comments are based on the [[modeling]] of Piggott and Pulham<ref name=ch04r75 />), illustrated and discussed along with [[:file:sedimentary-basin-analysis_fig4-32.png|Figures 9]] and [[:file:sedimentary-basin-analysis_fig4-33.png|10]].

Each of the isopach maps in this section is annotated with the area of active [[petroleum generation]] and migration. These comments are based on the [[modeling]] of Piggott and Pulham<ref name=ch04r75 />), illustrated and discussed along with [[:file:sedimentary-basin-analysis_fig4-32.png|Figures 9]] and [[:file:sedimentary-basin-analysis_fig4-33.png|10]].

==Interval A paleogeography==

==Interval A paleogeography==

==Depocenter summary==

==Depocenter summary==

[[file:sedimentary-basin-analysis_fig4-3.png|thumb|{{figure number|11}}Jurassic to recent sediment thickness and hydrocarbon occurrences in the GOM basin. From Winkler & Buffler (1988);{{citation needed}} courtesy AAPG.]]

[[file:sedimentary-basin-analysis_fig4-3.png|thumb|300px|{{figure number|11}}Jurassic to recent sediment thickness and hydrocarbon occurrences in the GOM basin. From Winkler & Buffler;<ref name=WinkerandBuffler>Winker, C. D., and R. T. Buffler, 1988, [http://archives.datapages.com/data/bulletns/1988-89/data/pg/0072/0003/0300/0318.htm Paleogeographic evolution of the early deep-water Gulf of Mexico and its margins, Jurassic to middle Cretaceous (Comanchean)]: AAPG Bulletin, vol. 72, p. 318-346</ref> courtesy AAPG.]]

Mapping age-specific isopach thicks defines laterally shifting sites of maximum deposition along the margin of the basin. Each of these [[depocenter]]s has a unique history of [[accumulation]] with consequent variations in [[maturation]], [[migration]], and entrapment histories. Evaluation of depocenter maps should include comparison of the results with the largerscale isopach maps ([[:file:sedimentary-basin-analysis_fig4-4.png|Figures 1]], [[:file:sedimentary-basin-analysis_fig4-3.png|11]]).

 

Mapping age-specific isopach thicks defines laterally shifting sites of maximum deposition along the margin of the basin. Each of these depocenters has a unique history of accumulation with consequent variations in [[maturation]], migration, and entrapment histories. Evaluation of depocenter maps should include comparison of the results with the largerscale isopach maps ([[:file:sedimentary-basin-analysis_fig4-3.png|Figures 11]], [[:file:sedimentary-basin-analysis_fig4-4.png|12]]).

===GOM depocenter summary===

===GOM depocenter summary===

In the case of the northern Gulf of Mexico, the depocenters prograde over the transitional crust and deform the underlying salt, forming a complex network of salt-cored anticlines and salt-withdrawal synclines. Between 2.5 and 2.0 Ma, the major northern Gulf of Mexico depocenter was focused offshore western Louisiana and eastern Texas. The westernmost part of this depocenter area, the High Island–East Breaks depocenter, appears to have been the input area for the ancestral Mississippi River system. The resulting depocenter has more than [[depth::16,000 ft]] (4875 m) of late Pliocene and early Pleistocene sediments deposited during a succession of high-amplitude sea level cycles (see section C, Depositional Sequences).

In the case of the northern Gulf of Mexico, the depocenters [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograde]] over the [[transitional crust]] and deform the underlying salt, forming a complex network of salt-cored anticlines and salt-withdrawal synclines. Between 2.5 and 2.0 Ma, the major northern Gulf of Mexico depocenter was focused offshore western Louisiana and eastern Texas. The westernmost part of this depocenter area, the High Island–East Breaks depocenter, appears to have been the input area for the ancestral Mississippi River system. The resulting depocenter has more than [[depth::16,000 ft]] (4875 m) of late Pliocene and early Pleistocene sediments deposited during a succession of high-amplitude sea level cycles (see section C, Depositional Sequences).

==See also==

==See also==

* [[Depocenters]]

* [[Depocenters]]

* [[Example: mapping fluvial input]]

* [[Example: mapping fluvial input]]

[[Category:Critical elements of the petroleum system]]  

[[Category:Critical elements of the petroleum system]]  

[[Category:Sedimentary basin analysis]]

[[Category:Sedimentary basin analysis]]