Changes

==Structural traps==

==Structural traps==

Within these minibasins, structural traps of gravity-flow sandstones formed

Within these minibasins, structural traps of [http://cdn.intechopen.com/pdfs-wm/25729.pdf gravity-flow sandstones] formed

* as fault-dependent closure at [[growth fault]]s,

* as fault-dependent closure at [[growth fault]]s,

* as anticlinal closure formed by rollover into growth faults, or

* as [http://www.glossary.oilfield.slb.com/en/Terms/a/anticline.aspx anticlinal closure] formed by [http://structuralgeology.50webs.com/pagef21.htm roll over] into growth faults, or

* by postdepositional tilting of sandstones that shale-out upstructure due to syndepositional pinching-out against sea-floor valley margins.<ref name=ch04r22>Bouma, A., H., 1982, [http://archives.datapages.com/data/specpubs/history2/data/a110/a110/0001/0550/0567.htm Intraslope basins in northwest Gulf of Mexico: A key to ancient submarine canyons and fans: Environmental processes: Model investigations of margin environmental and tectonic processes], in Watkins, J. S., and C. L. Drake, Studies in Continental Margin Geology: AAPG Memoir 34, p. 567–581.</ref><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>

* by postdepositional tilting of sandstones that shale out [[Dip|upstructure]] due to syndepositional pinching-out against sea-floor valley margins.<ref name=ch04r22>Bouma, A., H., 1982, [http://archives.datapages.com/data/specpubs/history2/data/a110/a110/0001/0550/0567.htm Intraslope basins in northwest Gulf of Mexico: A key to ancient submarine canyons and fans: Environmental processes: Model investigations of margin environmental and tectonic processes], in Watkins, J. S., and C. L. Drake, Studies in Continental Margin Geology: AAPG Memoir 34, p. 567–581.</ref><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>

==Stratigraphic traps==

==Stratigraphic traps==

Pure [[stratigraphic trap]]s occur where basinal sandstones completely bypassed updip areas subsequently filled by mud, providing both top seal and updip lateral seal.<ref name=ch04r22 /><ref name=ch04r36>Galloway, W., E., McGilvery, T., A., 1995, Facies of a submarine canyon fill reservoir complex, lower Wilcox Group (Paleocene), central Texas coastal plain, in Winn, R., D., Jr., Armentrout, J., M., eds., Turbidites and Associated Deep-Water Facies: WEPM Core Workshop 20, p. 1–23.</ref>

Pure [[stratigraphic trap]]s occur where basinal sandstones completely bypassed [[Dip|updip]] areas subsequently filled by mud, providing both top seal and updip lateral seal.<ref name=ch04r22 /><ref name=ch04r36>Galloway, W., E., McGilvery, T., A., 1995, Facies of a submarine canyon fill reservoir complex, lower Wilcox Group (Paleocene), central Texas coastal plain, in Winn, R., D., Jr., Armentrout, J., M., eds., Turbidites and Associated Deep-Water Facies: WEPM Core Workshop 20, p. 1–23.</ref>

==Timing of fault movement==

==Timing of fault movement==

Fault movement timing is critical for trap formation timing. [[Growth fault|Growth-fault]] rollover anti-clines develop by updip expansion and sediment entrapment on the downthrown side of the fault and consequent downdip sediment starvation and continued subsidence within the intraslope basin (see Figure 4-43 for geometries above the ''Trim A'' interval along fault A′). Thus, the updip trap for gravity-flow sandstone is the rollover into the fault, formed during the dynamic phase of fault movement.

Fault movement timing is critical for trap formation timing. [[Growth fault|Growth-fault]] [http://structuralgeology.50webs.com/pagef21.htm rollover anticlines] develop by [[Dp|updip]] expansion and sediment entrapment on the downthrown side of the fault and consequent [[Dip|downdip]] sediment starvation and continued subsidence within the intraslope basin (see Figure 4-43 for geometries above the ''Trim A'' interval along fault A′). Thus, the updip trap for [[http://cdn.intechopen.com/pdfs-wm/25729.pdf gravity gravity-flow sandstone] is the rollover into the fault, formed during the dynamic phase of fault movement.

==Fault A′==

==Fault A′==

In the East Breaks 160-161 minibasin, the [[Growth fault|fault]] splay fault A′ forms the northern boundary to the field (Figures 4-42 and 4-43). The dynamic phase of this fault is recorded by the wedge-shaped sediment thickening into the fault, deposited between pre-''Hyal B'' (ca. 1.00 Ma) time and late ''Trim A'' (ca. 0.56 Ma) time (Figure 4-31). Its growth phase began about 1.20 Ma.<ref name=ch04r10>Armentrout, J., M., Clement, J., F., 1990, Biostratigraphic calibration of depositional cycles: a case study in High Island–Galveston–East Breaks areas, offshore Texas: Proceedings, Gulf Coast Section SEPM 11th Annual Research Conference, p. 21–51.</ref><ref name=ch04r7>Armentrout, J., M., 1991, Paleontological constraints on depositional [[modeling]]: examples of integration of biostratigraphy and seismic stratigraphy, Pliocene–Pleistocene, Gulf of Mexico, in Weimer, P., Link, M., H., eds., Seismic Facies and Sedimentary Processes of Submarine Fans and Turbidite Systems: New York, Springer-Verlag, p. 137–170.</ref> Sea-floor expression of this fault clearly indicates offset of Holocene sediments, showing that the fault is currently active (Figure 4-43).

In the East Breaks 160-161 minibasin, the [[Growth fault|fault]] splay fault A′ forms the northern boundary to the field (Figures 4-42 and 4-43). The dynamic phase of this fault is recorded by the wedge-shaped sediment thickening into the fault, deposited between pre-''Hyal B'' (ca. 1.00 Ma) time of deposition and late ''Trim A'' (ca. 0.56 Ma) time of deposition (Figure 4-31). Its growth phase began about 1.20 Ma.<ref name=ch04r10>Armentrout, J., M., Clement, J., F., 1990, Biostratigraphic calibration of depositional cycles: a case study in High Island–Galveston–East Breaks areas, offshore Texas: Proceedings, Gulf Coast Section SEPM 11th Annual Research Conference, p. 21–51.</ref><ref name=ch04r7>Armentrout, J., M., 1991, Paleontological constraints on depositional [[modeling]]: examples of integration of biostratigraphy and seismic stratigraphy, Pliocene–Pleistocene, Gulf of Mexico, in Weimer, P., Link, M., H., eds., Seismic Facies and Sedimentary Processes of Submarine Fans and Turbidite Systems: New York, Springer-Verlag, p. 137–170.</ref> Sea-floor expression of this fault clearly indicates offset of Holocene sediments, showing that the fault is currently active (Figure 4-43).

==See also==

==See also==