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Sequence stratigraphy is the study of genetically related facies within a framework of chronostratigraphically significant surfaces.<ref name=ch17r92>Van Wagoner, J., C., Mitchum, R., M., Campion, K., M., Rahmanian, V., D., 1990, Siliciclastic sequence stratigraphy in well logs, cores, and outcrops: [http://store.aapg.org/detail.aspx?id=1196 AAPG Methods in Exploration 7], 55 p.</ref> Paleontologic data, integrated with seismic and well log data, are an integral part of sequence stratigraphic analysis. [[Paleontology]] provides two critical types of data:

[[Sequence stratigraphy]] is the study of genetically related facies within a framework of [http://www.stratigraphy.org/upload/bak/chron.htm chronostratigraphically] significant surfaces.<ref name=ch17r92>Van Wagoner, J., C., Mitchum, R., M., Campion, K., M., Rahmanian, V., D., 1990, Siliciclastic sequence stratigraphy in well logs, cores, and outcrops: [http://store.aapg.org/detail.aspx?id=1196 AAPG Methods in Exploration 7], 55 p.</ref> Paleontologic data, integrated with [[Seismic data|seismic]] and [[Basic open hole tools|well log data]], are an integral part of sequence stratigraphic analysis. [[Paleontology]] provides two critical types of data:

* Age control for chronostratigraphic horizons, especially sequence boundaries

* Age control for chronostratigraphic horizons, especially [[Definitions_of_depositional_system_elements#Sequence_boundaries|sequence boundaries]]

* Paleoenvironmental control for systems tract interpretations

* Paleoenvironmental control for [[Systems tracts and trap types|systems tract]] interpretations

==Age control==

==Age control==

Among chronostratigraphically significant surfaces, the sequence boundary and the maximum flooding surface (i.e., downlap surface on seismic profiles) are of particular importance. [[Paleontology]] provides two important constraints on these surfaces:

Among chronostratigraphically significant surfaces, the sequence boundary and the [[Definitions_of_depositional_system_elements#Maximum_flooding_surface|maximum flooding surface]] (i.e., [http://www.glossary.oilfield.slb.com/en/Terms/d/downlap.aspx downlap] surface on seismic profiles) are of particular importance. [[Paleontology]] provides two important constraints on these surfaces:

* Chronostratigraphic correlation controls<ref name=ch17r10>Baum, G., R., Vail, P., R., 1987, Sequence stratigraphy, allostratigraphy, isotope stratigraphy, and biostratigraphy: putting it all together in the Atlantic and Gulf Paleogene, in Innovative Biostratigraphic Approaches to Sequence Analysis: New Exploration Opportunities: Selected Papers and Illustrated Abstracts of the Eighth Annual Research conference of the Gulf Coast Section of the Society of Economic Paleontologists and Mineralogists Foundation, p. 15–23.</ref>

* Chronostratigraphic correlation controls<ref name=ch17r10>Baum, G., R., Vail, P., R., 1987, Sequence stratigraphy, allostratigraphy, isotope stratigraphy, and biostratigraphy: putting it all together in the Atlantic and Gulf Paleogene, in Innovative Biostratigraphic Approaches to Sequence Analysis: New Exploration Opportunities: Selected Papers and Illustrated Abstracts of the Eighth Annual Research conference of the Gulf Coast Section of the Society of Economic Paleontologists and Mineralogists Foundation, p. 15–23.</ref>

==Chronostratigraphic correlation==

==Chronostratigraphic correlation==

The sequence stratigraphy model postulates a worldwide succession of depositional events such as coastal onlap and oceanic anoxic events<ref name=ch17r5>Arthur, M., A., Dean, W., E., 1986, Cretaceous paleoceanography, in Tucholke, B., E., Vogt, P., R., eds., Decade of North American Geology, Western North Atlantic Basin Synthesis Volume: Geological Society of America, p. 617–630.</ref> primarily reflecting global cyclic changes in eustatic sea level. This succession ideally is represented by a sea level onlap-offlap curve such as the Haq et al.<ref name=ch17r43>Haq, B., U., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change, in Wilgus, C., K., Hastings, B., S., Kendall, C., G. St. C., Posamentier, H., W., Ross, C., A., Van Wagoner, John C., eds., Sea-level Change: An Integrated Approach: SEPM Special Publication 42, p. 71–108.</ref> cycle chart.

The sequence stratigraphy model postulates a worldwide succession of depositional events such as coastal [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=onlap onlap] and oceanic [http://www.merriam-webster.com/dictionary/anoxic anoxic] events<ref name=ch17r5>Arthur, M., A., Dean, W., E., 1986, Cretaceous paleoceanography, in Tucholke, B., E., Vogt, P., R., eds., Decade of North American Geology, Western North Atlantic Basin Synthesis Volume: Geological Society of America, p. 617–630.</ref> primarily reflecting global cyclic changes in [http://www.sepmstrata.org/Terminology.aspx?id=eustatic eustatic] sea level. This succession ideally is represented by a sea level onlap-[http://www.answers.com/topic/offlap offlap] curve such as the Haq et al.<ref name=ch17r43>Haq, B., U., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change, in Wilgus, C., K., Hastings, B., S., Kendall, C., G. St. C., Posamentier, H., W., Ross, C., A., Van Wagoner, John C., eds., Sea-level Change: An Integrated Approach: SEPM Special Publication 42, p. 71–108.</ref> cycle chart.

One problem frequently confronted in sequence studies is determining which of these worldwide events is represented in the section of interest. Correlating a local section to the global cycles requires accurate and precise biostratigraphy, either through zonal age determination or by providing the necessary age constraints on magnetostratigraphic or isotope stratigraphic interpretations. When based on reliable age control, correlation with the succession of global processes can be a valuable predictive stratigraphic tool for understanding the temporal and areal distribution of reservoir, source, and seal rocks.

One problem frequently confronted in sequence studies is determining which of these worldwide events is represented in the section of interest. Correlating a local section to the global cycles requires accurate and precise [[Biostratigraphic correlation and age determination|biostratigraphy]], either through zonal age determination or by providing the necessary age constraints on [[magnetostratigraphic]] or [[Stable isotope stratigraphy|isotope stratigraphic]] interpretations. When based on reliable age control, correlation with the succession of global processes can be a valuable predictive stratigraphic tool for understanding the temporal and areal distribution of [[reservoir]], [[Source rock|source]], and [[seal]] rocks.

Biostratigraphic correlation between sections separated by a fault zone or other major geologic feature is frequently much more reliable than seismic reflectors or well log picks. Correlation across [[growth fault]]s, where stratal thickness and character can vary greatly from the high to the low side, is a notable example.

Biostratigraphic correlation between sections separated by a [[fault]] zone or other major geologic feature is frequently much more reliable than [[Seismic data|seismic reflectors]] or [[Basic open hole tools|well log]] picks. Correlation across [[growth fault]]s, where stratal thickness and character can vary greatly from the high to the low side, is a notable example.

==Stratigraphic distribution of onlap events==

==Stratigraphic distribution of onlap events==

[[file:applied-paleontology_fig17-23.png|thumb|300px|{{figure number|1}}Stratigraphic distribution of onlap events, tectonic episodes (“s”-shaped arrows), oceanic anoxic events (OAE), and “crises” of the shallow water biota (<span class="noglossary">BC</span>) in various parts of the world during part of the Mesozoic.<ref name=ch17r80 /> Landward is toward the right in each column. Courtesy AAPG.]]

[[file:applied-paleontology_fig17-23.png|thumb|300px|{{figure number|1}}Stratigraphic distribution of onlap events, tectonic episodes (“s”-shaped arrows), oceanic anoxic events (OAE), and “crises” of the shallow water biota (<span class="noglossary">BC</span>) in various parts of the world during part of the Mesozoic.<ref name=ch17r80 /> Landward is toward the right in each column. Courtesy AAPG.]]

[[:file:applied-paleontology_fig17-23.png|Figure 1]] illustrates the stratigraphic distribution of onlap events, tectonic episodes (“s”-shaped arrows), oceanic anoxic events (OAE), and “crises” of the shallow water biota (<span class="noglossary">BC</span>) in various parts of the world during part of the Mesozoic.<ref name=ch17r80>Simo, J. A. T., Scott, R. W., Masse, J.-P., 1993, [http://archives.datapages.com/data/specpubs/carbona1/data/a044/a044/0001/0000/0001.htm Cretaceous carbonate platforms: an overview], in Simo, J., A., T., Scott, R., W., Masse, J.-P., eds., Cretaceous Carbonate Platforms: [http://store.aapg.org/detail.aspx?id=1188 AAPG Memoir 56], p. 1–14.</ref> Landward is toward the right in each column.

[[:file:applied-paleontology_fig17-23.png|Figure 1]] illustrates the stratigraphic distribution of [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=onlap onlap] events, [[Tectonics|tectonic]] episodes (“s”-shaped arrows), oceanic [http://www.merriam-webster.com/dictionary/anoxic anoxic] events (OAE), and “crises” of the shallow water biota (<span class="noglossary">BC</span>) in various parts of the world during part of the Mesozoic.<ref name=ch17r80>Simo, J. A. T., Scott, R. W., Masse, J.-P., 1993, [http://archives.datapages.com/data/specpubs/carbona1/data/a044/a044/0001/0000/0001.htm Cretaceous carbonate platforms: an overview], in Simo, J., A., T., Scott, R., W., Masse, J.-P., eds., Cretaceous Carbonate Platforms: [http://store.aapg.org/detail.aspx?id=1188 AAPG Memoir 56], p. 1–14.</ref> Landward is toward the right in each column.

==Numerical ages==

==Numerical ages==