Changes

The tectonic history of the GOM basin provides the regional framework for mapping elements and processes of the petroleum systems within the High Island–East Breaks area. Following is a summary of the tectonic history of the basin.

The tectonic history of the GOM basin provides the regional framework for mapping elements and processes of the petroleum systems within the High Island–East Breaks area. Following is a summary of the tectonic history of the basin.

* Within the GOM rift basin, major areas of [[transitional crust]] formed between [[continental crust]] and Late Jurassic oceanic crust. Middle Jurassic crustal attenuation associated with the transitional crust formed sags in which evaporites were deposited.

* Within the GOM rift basin, major areas of [[transitional crust]] formed between [[continental crust]] and Late Jurassic oceanic [[crust]]. Middle Jurassic crustal attenuation associated with the transitional crust formed sags in which evaporites were deposited.

* During the Late Jurassic and Early Cretaceous, thermal subsidence of the basin center and relatively high sea level formed extensive carbonate platforms along the basin margin and sediment starvation of the basin center. Organic-rich, oil-prone marine sediments were deposited within low-oxygen environments of this sediment-starved basin. These rocks later became the primary source of oil and gas—some of which migrated to and is stored within porous zones of the carbonate platforms.

* During the Late Jurassic and Early Cretaceous, thermal subsidence of the basin center and relatively high sea level formed extensive carbonate platforms along the basin margin and sediment starvation of the basin center. Organic-rich, oil-prone marine sediments were deposited within low-oxygen environments of this sediment-starved basin. These rocks later became the primary source of oil and gas—some of which migrated to and is stored within porous zones of the carbonate platforms.

* Late Cretaceous and [[Cenozoic]] siliciclastic sedimentation formed thick, [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] prisms over the transitional crust and differentially loaded the Late Jurassic salt. The [[Deformation|deformed]] salt created anticlinal highs bordering sediment-filled [[Syncline|synclinal]] lows, which continued to subside and provide sediment transport pathways downslope. The deformation of the salt and associated sediments formed both structural and [[stratigraphic trap]]s within the siliciclastic section. Sedimentary burial and salt-thickness/mobility patterns affect [[Petroleum generation|hydrocarbon generation]] due to variations in the thermal conductivity of salt. Intersecting fault trends, one paralleling northwest–southeast-trending [[basement]] faults and a second associated with depositional strike-oriented [[growth fault]]s, provide vertical avenues for [[migration]] of hydrocarbons from deeply buried mature Mesozoic [[source rock]]s upward into reservoir rocks of Jurassic, Cretaceous, and Cenozoic age.

* Late Cretaceous and [[Cenozoic]] siliciclastic sedimentation formed thick, [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] prisms over the transitional crust and differentially loaded the Late Jurassic salt. The [[Deformation|deformed]] salt created anticlinal highs bordering sediment-filled [[Syncline|synclinal]] lows, which continued to subside and provide sediment transport pathways downslope. The deformation of the salt and associated sediments formed both structural and [[stratigraphic trap]]s within the siliciclastic section. Sedimentary burial and salt-thickness/mobility patterns affect [[Petroleum generation|hydrocarbon generation]] due to variations in the thermal conductivity of salt. Intersecting fault trends, one paralleling northwest–southeast-trending [[basement]] faults and a second associated with depositional strike-oriented [[growth fault]]s, provide vertical avenues for [[migration]] of hydrocarbons from deeply buried mature Mesozoic [[source rock]]s upward into reservoir rocks of Jurassic, Cretaceous, and Cenozoic age.