Changes

==Discussion of GOM basin==

==Discussion of GOM basin==

Much of the petroleum discovered within the northern GOM basin is in Neogene anticlinal and [[stratigraphic trap]]s developed as a consequence of interaction between Jurassic salt and Cenozoic siliciclastic [[Depocenter#Sediment_supply_rate_and_facies_patterns|progradation]]. The basic model consists of sediment prograding into the basin and differentially loading the plastic salt, causing diapirs and [[growth fault]]s to develop.<ref name=ch04r98>Trippet, A. R., 1981, Characteristics of diapirs on the outer continental shelf–upper continental slope boundary, northwest Gulf of Mexico: Gulf Coast Assoc. of Geological Societies Transactions, vol. 31, p. 391–397.</ref><ref name=ch04r46>Ingram, R. J., 1991, Salt tectonics, in D. Goldthwaite, ed., An Introduction to Central Gulf Coast Geology: New Orleans Geological Society, p. 31–60.</ref> Two different interpretations of the present-day geology are presented below in two different structural cross sections. [[Migration]] of hydrocarbons from Mesozoic and early [[Tertiary]] organic-rich rocks are significantly affected by the selection of either of these two interpretations of salt [[deformation]].

Much of the petroleum discovered within the northern GOM basin is in Neogene anticlinal and [[stratigraphic trap]]s developed as a consequence of interaction between Jurassic salt and [[Cenozoic]] siliciclastic [[Depocenter#Sediment_supply_rate_and_facies_patterns|progradation]]. The basic model consists of sediment prograding into the basin and differentially loading the plastic salt, causing diapirs and [[growth fault]]s to develop.<ref name=ch04r98>Trippet, A. R., 1981, Characteristics of diapirs on the outer continental shelf–upper continental slope boundary, northwest Gulf of Mexico: Gulf Coast Assoc. of Geological Societies Transactions, vol. 31, p. 391–397.</ref><ref name=ch04r46>Ingram, R. J., 1991, Salt tectonics, in D. Goldthwaite, ed., An Introduction to Central Gulf Coast Geology: New Orleans Geological Society, p. 31–60.</ref> Two different interpretations of the present-day geology are presented below in two different structural cross sections. [[Migration]] of hydrocarbons from Mesozoic and early [[Tertiary]] organic-rich rocks are significantly affected by the selection of either of these two interpretations of salt [[deformation]].

==Traditional structure cross section==

==Traditional structure cross section==

Traditional regional cross sections, such as in the figure below, have shown highly [[Deformation|deformed]] salt rooted within the in-place Middle Jurassic mother salt. Such cross sections have been used to suggest that successive [[Depocenter#Sediment_supply_rate_and_facies_patterns|progradation]] of siliciclastics loaded and displaced the salt as each sedimentary cycle's depocenter stepped progressively basinward. Differential loading of the salt formed deeply rooted diapirs and shallow [[growth fault]]s as a result of sediment downbuilding and consequent displacement of salt. Mature [[source rock]]s occurring between the deeply rooted diapirs could yield hydrocarbons able to migrate within each salt-walled compartment of each depocenter.

Traditional regional cross sections, such as in the figure below, have shown highly [[Deformation|deformed]] salt rooted within the in-place Middle Jurassic mother salt. Such cross sections have been used to suggest that successive [[Depocenter#Sediment_supply_rate_and_facies_patterns|progradation]] of siliciclastics loaded and displaced the salt as each sedimentary cycle's [[depocenter]] stepped progressively basinward. Differential loading of the salt formed deeply rooted diapirs and shallow [[growth fault]]s as a result of sediment downbuilding and consequent displacement of salt. Mature [[source rock]]s occurring between the deeply rooted diapirs could yield hydrocarbons able to migrate within each salt-walled compartment of each depocenter.

==Recent structure cross section==

==Recent structure cross section==

More recent models of salt [[deformation]] recognize both the in-place Middle Jurassic mother salt and displaced sheets of Middle Jurassic salt that have become detached from the mother salt as shown in the figure below. The detached salt is emplaced progressively over younger sediments because of the passive response to differential loading by sediment and gravitational forces. Basinward gravitational slope failure forms major [[growth fault]] systems on the upper slope and toe-thrust structures downslope.<ref name=ch04r24>Bruce, C., H., 1973, [http://archives.datapages.com/data/bulletns/1971-73/data/pg/0057/0005/0850/0878.htm Pressured shale and related sediment deformation: mechanism for development of regional contemporaneous faults]: AAPG Bulletin, vol. 57, p. 878–886., 10., 1306/819A4352-16C5-11D7-8645000102C1865D</ref> Each “pulse” of salt displacement evolves through a new generation of deformation.<ref name=ch04r32>Fiduk, J., C., Behrens, E., W., Buffler, R., T., 1989, Distribution and movement of salt on the Texas–Louisiana continental slope, Garden Banks and eastern East Breaks areas, Gulf of Mexico: Proceedings, Gulf Coast Section SEPM 10th Annual Research conference, p. 39–47.</ref><ref name=ch04r110>West, D., B., 1989, [http://archives.datapages.com/data/bulletns/1988-89/data/pg/0073/0012/1450/1472.htm Model for salt deformation on deep margin of central Gulf of Mexico basin]: AAPG Bulletin, vol. 73, p. 1472–1482.</ref><ref name=ch04r56>Koyi, H., 1993, [[Modeling]] of segmentation and emplacement of salt sheets in anisotropic overburden: Selected Papers, Gulf Coast Section SEPM 13th Annual Research conference, p. 135–142.</ref><ref name=ch04r66>McGuinness, D., B., Hossack, J., R., 1993, The development of allochthonous salt sheets as controlled by the rates of extension, sedimentation, and salt supply: Proceedings, Gulf Coast Section SEPM 14th Annual Research conference, p. 127–139.</ref> Maturing source rocks of Mesozoic and early Tertiary age can yield hydrocarbons that may migrate vertically along growth faults and salt walls, through holes in salt canopies, laterally below salt, or within sandstones between salt sheets.

More recent models of salt [[deformation]] recognize both the in-place Middle Jurassic mother salt and displaced sheets of Middle Jurassic salt that have become detached from the mother salt as shown in the figure below. The detached salt is emplaced progressively over younger sediments because of the passive response to differential loading by sediment and gravitational forces. Basinward gravitational slope failure forms major [[growth fault]] systems on the upper slope and toe-thrust structures downslope.<ref name=ch04r24>Bruce, C. H., 1973, [http://archives.datapages.com/data/bulletns/1971-73/data/pg/0057/0005/0850/0878.htm Pressured shale and related sediment deformation: mechanism for development of regional contemporaneous faults]: AAPG Bulletin, vol. 57, p. 878–886., 10., 1306/819A4352-16C5-11D7-8645000102C1865D</ref> Each “pulse” of salt displacement evolves through a new generation of deformation.<ref name=ch04r32>Fiduk, J. C., E. W. Behrens, and R. T. Buffler, 1989, Distribution and movement of salt on the Texas–Louisiana continental slope, Garden Banks and eastern East Breaks areas, Gulf of Mexico: Proceedings, Gulf Coast Section SEPM 10th Annual Research conference, p. 39–47.</ref><ref name=ch04r110>West, D. B., 1989, [http://archives.datapages.com/data/bulletns/1988-89/data/pg/0073/0012/1450/1472.htm Model for salt deformation on deep margin of central Gulf of Mexico basin]: AAPG Bulletin, vol. 73, p. 1472–1482.</ref><ref name=ch04r56>Koyi, H., 1993, Modeling of segmentation and emplacement of salt sheets in anisotropic overburden: Selected Papers, Gulf Coast Section SEPM 13th Annual Research conference, p. 135–142.</ref><ref name=ch04r66>McGuinness, D. B., and J. R. Hossack, 1993, The development of allochthonous salt sheets as controlled by the rates of extension, sedimentation, and salt supply: Proceedings, Gulf Coast Section SEPM 14th Annual Research conference, p. 127–139.</ref> Maturing source rocks of Mesozoic and early Tertiary age can yield hydrocarbons that may migrate vertically along growth faults and salt walls, through holes in salt canopies, laterally below salt, or within sandstones between salt sheets.

==Basin evolution==

==Basin evolution==

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file:sedimentary-basin-analysis_fig4-8.png|{{figure number|1}}Modified after Antoine et al.<ref name=ch04r4>Antoine, J., W., Ray, R., G. Jr., Pyle, T., G., Bryant, W., R., 1974, Continental margins of the Gulf of Mexico, in Burk, C., A., Drake, C., L., eds., The Geology of Continental Margins: New York, Springer-Verlag, p. 683–693.</ref> Courtesy Springer-Verlag.

file:sedimentary-basin-analysis_fig4-8.png|{{figure number|1}}Modified after Antoine et al.<ref name=ch04r4>Antoine, J. W., R. G. Ray, Jr., T. G. Pyle, and W. R. Bryant, 1974, Continental margins of the Gulf of Mexico, in C. A. Burk, and C. L. Drake, eds., The Geology of Continental Margins: New York, Springer-Verlag, p. 683–693.</ref> Courtesy Springer-Verlag.

file:sedimentary-basin-analysis_fig4-9.png|{{figure number|2}}From Hall et al.<ref name=Halletal_1993>Hall, D. J., B. E. Bowen, R. N. Rosen, S. Wu, and A. W. Bally, 1993, Mesozoic and early Cenozoic development of the Texas margin: A new integrated hydrocarbon system study, northern Gulf of Mexico basin: Abstracts, 1st Latin American Geophysical Conference, p. 1-4.</ref> Courtesy Gulf Coast SEPM.

file:sedimentary-basin-analysis_fig4-9.png|{{figure number|2}}From Hall et al.<ref name=Halletal_1993>Hall, D. J., B. E. Bowen, R. N. Rosen, S. Wu, and A. W. Bally, 1993, Mesozoic and early Cenozoic development of the Texas margin: A new integrated hydrocarbon system study, northern Gulf of Mexico basin: Abstracts, 1st Latin American Geophysical Conference, p. 1-4.</ref> Courtesy Gulf Coast SEPM.

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

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

[[Category:Sedimentary basin analysis]]

[[Category:Sedimentary basin analysis]]