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Line 60: + + − + − − [[file:paleontology_fig3.png|thumb|{{figure number|3}}Correlation of Rodessa Formation lithofacies at Running Duke Field, Houston County, Texas. Cores are indicated by solid vertical lines. (From <ref name=pt05r142 />.)]]
→Exploitation applications
Fossil assemblages may provide evidence for local environmental conditions that also influenced deposition of potential reservoirs and source rocks. For example, reefs are formed by a community of interacting species that live together under the same conditions. Communities of terrestrial organisms normally are transported and concentrated into fluvial or lacustrine deposits and are mixed with aquatic organisms. Marine organisms may also be transported, and species from different communities may be mixed by storms and other currents. (For more information on depositional environments, see [[Lithofacies and environmental analysis of clastic depositional systems]] and [[Carbonate reservoir models: facies, diagenesis, and flow characteristics]]).
Fossil assemblages may provide evidence for local environmental conditions that also influenced deposition of potential reservoirs and source rocks. For example, reefs are formed by a community of interacting species that live together under the same conditions. Communities of terrestrial organisms normally are transported and concentrated into fluvial or lacustrine deposits and are mixed with aquatic organisms. Marine organisms may also be transported, and species from different communities may be mixed by storms and other currents. (For more information on depositional environments, see [[Lithofacies and environmental analysis of clastic depositional systems]] and [[Carbonate reservoir models: facies, diagenesis, and flow characteristics]]).
[[file:paleontology_fig3.png|thumb|{{figure number|3}}Correlation of Rodessa Formation lithofacies at Running Duke Field, Houston County, Texas. Cores are indicated by solid vertical lines. (From <ref name=pt05r142 />.)]]
===Reservoirs===
===Reservoirs===
An example of how fossil assemblages affect [[reservoir quality]] and distribution can be seen in the Lower Cretaceous reef complexes of the Running Duke Field, Houston County, Texas. In these reef complexes, reservoir properties are partially controlled by the ancient communities of reef-building mollusks, corals, and algae (Figure 3<ref name=pt05r142>Scott, R. W., 1990, Models and stratigraphy of mid-Cretaceous reef communities, Gulf of Mexico: SEPM Concepts in Sedimentology and Paleontology, v. 2, 102 p.</ref>. The reefs built by corals, algae, and rudists formed shoal water areas where waves and other currents deposited oolites and well sorted bioclasts. Diagenetic conditions in this facies formed reservoir [[porosity]]. Recognition of the fossils in cuttings, cores, and thin sections complement petrographic and log analyses and aid in the recognition of reservoir quality rocks.
An example of how fossil assemblages affect [[reservoir quality]] and distribution can be seen in the Lower Cretaceous reef complexes of the Running Duke Field, Houston County, Texas. In these reef complexes, reservoir properties are partially controlled by the ancient communities of reef-building mollusks, corals, and algae ([[:ile:paleontology_fig3.png|Figure 3]]).<ref name=pt05r142>Scott, R. W., 1990, Models and stratigraphy of mid-Cretaceous reef communities, Gulf of Mexico: SEPM Concepts in Sedimentology and Paleontology, v. 2, 102 p.</ref> The reefs built by corals, algae, and rudists formed shoal water areas where waves and other currents deposited oolites and well sorted bioclasts. Diagenetic conditions in this facies formed reservoir [[porosity]]. Recognition of the fossils in cuttings, cores, and thin sections complement petrographic and log analyses and aid in the recognition of reservoir quality rocks.
===Source rocks===
===Source rocks===