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  = 4-39

  | topg    = 4-123

  | topg    = 4-39

  | 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 example==

==GOM basin example==

The seismic reflection profile below is from the High Island South Addition area, GOM basin, [[distance::20 mi]] east of the East Breaks shelf-margin delta. It illustrates the vertical stacking of seven depositional sequences within a fault-bounded salt-withdrawal basin. Down arrows at the inflection point of each clinoform identify the top of the clinoform of each sequence. In general, each cycle consists of (1) a thick basinal package of relatively discontinuous, variable-amplitude, hummocky reflections that grade upward into (2) parallel, continuous, uniform amplitude reflections, overlain by (3) a [[Depocenter#Sediment_supply_rate_and_facies_patterns|prograding]] clinoform that downlaps the underlying facies. Each clinoform is interpreted as a shelf-margin delta prograding into this outer-shelf to upper-slope fault-bounded basin as shown by the presentday sea floor profile. The seven prograding clinoforms are mapped into a nearby well and are correlated with two-cycle charts ([[:file:sedimentary-basin-analysis_fig4-25.png|Figure 1]]). Cycle 1 of this figure correlates with the clinoform package of [[:file:sedimentary-basin-analysis_fig4-19.png|Figure 2]].

 

 

The seismic reflection profile below is from the High Island South Addition area, GOM basin, [[distance::20 mi]] east of the East Breaks shelf-margin delta. It illustrates the vertical stacking of seven depositional sequences within a fault-bounded salt-withdrawal basin. Down arrows at the inflection point of each clinoform identify the top of the clinoform of each sequence. In general, each cycle consists of (1) a thick basinal package of relatively discontinuous, variable-amplitude, hummocky reflections that grade upward into (2) parallel, continuous, uniform amplitude reflections, overlain by (3) a prograding clinoform that downlaps the underlying facies. Each clinoform is interpreted as a shelf-margin delta prograding into this outer-shelf to upper-slope fault-bounded basin as shown by the presentday sea floor profile. The seven prograding clinoforms are mapped into a nearby well and are correlated with two-cycle charts ([[:file:sedimentary-basin-analysis_fig4-25.png|Figure 1]]). Cycle 1 of this figure correlates with the clinoform package of [[:file:sedimentary-basin-analysis_fig4-19.png|Figure 2]].

==Interpretation of example==

==Interpretation of example==

The nearly vertical stacking of seven shelf-margin clinoforms suggests that accommodation space was created in the same area during seven cycles of progradation. The accommodation space is formed by down-to-the-north movement on the fault. This fault is part of a counter-regional listric growth fault that soles out into salt layers at depth. Movement on the fault occurred at a rate permitting the vertical stacking of shelf-margin clinoforms during each glacial/interglacial sea level cycle rather than progressive basinward progradation of successive clinoforms across a stable shelf-slope profile. This pattern clearly demonstrates the interplay of sediment supply, tectonics, climate, and sea level.<ref name=ch04r18>Beard, J., H., Sangree, J., B., Smith, L., A., 1982, [http://archives.datapages.com/data/bulletns/1982-83/data/pg/0066/0002/0150/0158.htm Quaternary chronology, paleoclimate, depositional sequences, and eustatic cycles]: AAPG Bulletin, vol. 66, p. 158–169.</ref><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>

The nearly vertical stacking of seven shelf-margin clinoforms suggests that accommodation space was created in the same area during seven cycles of progradation. The accommodation space is formed by down-to-the-north movement on the fault. This fault is part of a counter-regional listric [[growth fault]] that soles out into salt layers at depth. Movement on the fault occurred at a rate permitting the vertical stacking of shelf-margin clinoforms during each glacial/interglacial sea level cycle rather than progressive basinward progradation of successive clinoforms across a stable shelf-slope profile. This pattern clearly demonstrates the interplay of sediment supply, tectonics, climate, and sea level.<ref name=ch04r18>Beard, J., H., Sangree, J., B., Smith, L., A., 1982, [http://archives.datapages.com/data/bulletns/1982-83/data/pg/0066/0002/0150/0158.htm Quaternary chronology, paleoclimate, depositional sequences, and eustatic cycles]: AAPG Bulletin, vol. 66, p. 158–169.</ref><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>

==See also==

==See also==

* [[Depositional sequence]]

* [[East Breaks depositional sequence]]

* [[Definitions of depositional system elements]]

* [[Definitions of depositional system elements]]

* [[Identifying depositional sequences]]

* [[Identifying depositional sequences]]

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

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

[[Category:Sedimentary basin analysis]]

[[Category:Sedimentary basin analysis]]