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==Paleoenviron-mental trends==

==Paleoenvironmental trends==

[[file:applied-paleontology_fig17-25.png|300px|thumb|{{figure number|3}}The utility of variations in palynological assemblages, reflecting differing paleoenvironmental settings, when differentiating and identifying systems tracts. Published with the permission of Exxon.]]

[[file:applied-paleontology_fig17-25.png|300px|thumb|{{figure number|3}}The utility of variations in palynological assemblages, reflecting differing paleoenvironmental settings, when differentiating and identifying systems tracts. Published with the permission of Exxon.]]

In addition to seismic, lithofacies, and well log signatures<ref name=ch17r92 /> sequence stratigraphic surfaces and systems tracts can be recognized from paleoenvironmental trends evident from several types of paleontologic analyses:

In addition to [[Seismic data|seismic]], [[lithofacies]], and [[Basic open hole tools|well log]] signatures<ref name=ch17r92 /> sequence stratigraphic surfaces and systems tracts can be recognized from paleoenvironmental trends evident from several types of paleontologic analyses:

* '''Paleobathymetry'''—changes in benthic faunal composition can help identify relative sea level changes, e.g., benthic foraminiferal [[Fossil assemblage|biofacies]]<ref name=ch17r3>Armentrout, J., M., 1987, Integration of biostratigraphy and seismic stratigraphy: Pliocene–Pleistocene, Gulf of Mexico, 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. 6–14.</ref>

* '''[[Paleobathymetry]]'''—changes in [http://www.thefreedictionary.com/benthic benthic] faunal composition can help identify relative sea level changes, e.g., benthic [[foraminifera]]l [[Fossil assemblage|biofacies]]<ref name=ch17r3>Armentrout, J., M., 1987, Integration of biostratigraphy and seismic stratigraphy: Pliocene–Pleistocene, Gulf of Mexico, 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. 6–14.</ref>

* '''Distance from shoreline'''—changes in the relative abundance of marine vs. land-derived forms (e.g., dinoflagellate-pollen ratios) may reflect shoreline advances and retreats

* '''Distance from shoreline'''—changes in the relative abundance of marine vs. land-derived forms (e.g., [[Palynomorphs_(organic-walled_microfossils)#Dinoflagellates|dinoflagellate]]-[[Palynomorphs_(organic-walled_microfossils)#Spores_and_pollen|pollen]] ratios) may reflect shoreline advances and retreats

* '''Climatic cycles'''—fluctuations of warm- and cold-water indicators in marine environments [e.g., calcareous nannofossils<ref name=ch17r78>Shaffer, B., L., 1987, The potential of calcareous nannofossils for recognizing Plio–Pleistocene climatic cycles and sequence boundaries on the shelf, 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. 142–145.</ref> or planktonic foraminifera<ref name=ch17r63>Martin, R., E., Neff, E., D., Johnson, G., W., Krantz, D., E., 1993, Biostratigraphic expression of Pleistocene sequence boundaries, Gulf of Mexico: Palaios, vol. 8, no. 2, p. 155–171., 10., 2307/3515169</ref>] may reflect sea level changes during periods of glacio-eustasy. Variations in arid vs. wet climates reflected in land-based flora (e.g., palynomorphs) or lacustrine fauna (e.g., ostracodes) help identify climatic changes that control the development of stratigraphic sequences.

* '''Climatic cycles'''—fluctuations of warm- and cold-water indicators in marine environments [e.g., [[Calcareous_microfossils#Calcareous_nannofossils|calcareous nannofossils]]<ref name=ch17r78>Shaffer, B., L., 1987, The potential of calcareous nannofossils for recognizing Plio–Pleistocene climatic cycles and sequence boundaries on the shelf, 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. 142–145.</ref> or [[Microfossils in exploration|planktonic foraminifera]]<ref name=ch17r63>Martin, R., E., Neff, E., D., Johnson, G., W., Krantz, D., E., 1993, Biostratigraphic expression of Pleistocene sequence boundaries, Gulf of Mexico: Palaios, vol. 8, no. 2, p. 155–171., 10., 2307/3515169</ref>] may reflect sea level changes during periods of glacio-eustasy. Variations in arid vs. wet climates reflected in land-based flora (e.g., [[Palynomorphs (organic-walled microfossils)|palynomorphs]]) or [http://www.merriam-webster.com/dictionary/lacustrine lacustrine] fauna (e.g., [[Calcareous_microfossils#Ostracods|ostracods]]) help identify climatic changes that control the development of stratigraphic sequences.

[[:file:applied-paleontology_fig17-25.png|Figure 3]] illustrates the utility of variations in palynological assemblages, reflecting differing paleoenvironmental settings, when differentiating and identifying systems tracts.

[[:file:applied-paleontology_fig17-25.png|Figure 3]] illustrates the utility of variations in palynological assemblages, reflecting differing paleoenvironmental settings, when differentiating and identifying systems tracts.