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Recognizing stacked depositional sequences in seismic profiles (view source)
Revision as of 19:18, 30 January 2014
, 19:18, 30 January 2014Initial import
{{publication
| image = exploring-for-oil-and-gas-traps.png
| width = 120px
| series = Treatise in Petroleum Geology
| title = Exploring for Oil and Gas Traps
| part = Critical elements of the petroleum system
| chapter = Sedimentary basin analysis
| frompg = 4-1
| topg = 4-123
| author = John M. Armentrout
| link = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
Depositional sequences can stack into successions of sequences if accommodation space permits preservation of successive sequences. Seismically, stacked sequences are expressed as repetitious reflection patterns.
==GOM basin example==
The seismic reflection profile below is from the High Island South Addition area, GOM basin, [[length::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 (Figure 4-25). Cycle 1 of this figure correlates with the clinoform package of Figure 4-19.
[[file:sedimentary-basin-analysis_fig4-25.png|thumb|{{figure number|4-25}}. Copyright: Armentrout (1993); courtesy Gulf Coast SEPM.]]
==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 (see .<ref name=ch04r18>Beard, J., H., Sangree, J., B., Smith, L., A., 1982, 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==
* [[Depositional sequences]]
* [[Definitions of depositional system elements]]
* [[Identifying depositional sequences]]
* [[Identifying depositional sequences in seismic sections]]
* [[Identifying depositional sequences from biostratigraphic data]]
* [[Recognizing stacked depositional sequences from well data]]
==References==
{{reflist}}
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Critical elements of the petroleum system]]
[[Category:Sedimentary basin analysis]]
| image = exploring-for-oil-and-gas-traps.png
| width = 120px
| series = Treatise in Petroleum Geology
| title = Exploring for Oil and Gas Traps
| part = Critical elements of the petroleum system
| chapter = Sedimentary basin analysis
| frompg = 4-1
| topg = 4-123
| author = John M. Armentrout
| link = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
Depositional sequences can stack into successions of sequences if accommodation space permits preservation of successive sequences. Seismically, stacked sequences are expressed as repetitious reflection patterns.
==GOM basin example==
The seismic reflection profile below is from the High Island South Addition area, GOM basin, [[length::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 (Figure 4-25). Cycle 1 of this figure correlates with the clinoform package of Figure 4-19.
[[file:sedimentary-basin-analysis_fig4-25.png|thumb|{{figure number|4-25}}. Copyright: Armentrout (1993); courtesy Gulf Coast SEPM.]]
==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 (see .<ref name=ch04r18>Beard, J., H., Sangree, J., B., Smith, L., A., 1982, 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==
* [[Depositional sequences]]
* [[Definitions of depositional system elements]]
* [[Identifying depositional sequences]]
* [[Identifying depositional sequences in seismic sections]]
* [[Identifying depositional sequences from biostratigraphic data]]
* [[Recognizing stacked depositional sequences from well data]]
==References==
{{reflist}}
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Critical elements of the petroleum system]]
[[Category:Sedimentary basin analysis]]