Eolian Environments | Eolian Environment in Petroleum Geology?

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Eolian-Environments, Sedimentology, geology

Associated Facies Eolian Environments

Generally speaking, desert dune areas are determined by a limited range of physical parameters, most of which do not involve the depositional variations introduced by water. For this reason, subfacies in this environment are localized and usually minor. In addition, the often regional continuity of sand means that facies changes are large-scale. Frequently, adjacent environments are thickly evaporitic, whether coastal (wadisabkha) or inland (large salt lakes). Associated desert facies have already been mentioned; they often include alluvial fans, bajadas, playas, braided streams.(Figure 1, Idealized block diagram of a generic desert environment.) The occurrence of sand dunes on barrier islands and spits has also been discussed.

block diagram of a generic desert environment, desert environment, Eolian Environments, Eolian environment, Petroleum geology, Sediment transport, Aeolian deposition, Wind-blown sediments, Dune morphology, Cross-bedding, Sand accumulation, Dust deposition, Erosion features, Wind direction, Eolian facies, Grain size distribution, Sedimentary structures, Stratigraphy, Paleoclimate, Eolian reservoirs, Reservoir quality, Permeability, Porosity, Diagenesis, Compaction, Cementation, Well log analysis, Reservoir characterization — **FIGURE 1**

Today, a number of dune complexes are trimmed by rivers (which cannot be overcome by dune migration) and their alluvial plains.

In addition to these common associations, eolianites frequently occur immediately above a major unconformity, or as one of several facies sandwiched within a series of more minor erosion surfaces marking an episode of fluctuation between sandy marine and nonmarine environments.

(Figure 2 and Figure 3,

marine and nonmarine environments, Desert environment, Eolian Environments, Eolian environment, Petroleum geology, Sediment transport, Aeolian deposition, Wind-blown sediments, Dune morphology, Cross-bedding, Sand accumulation, Dust deposition, Erosion features, Wind direction, Eolian facies, Grain size distribution, Sedimentary structures, Stratigraphy, Paleoclimate, Eolian reservoirs, Reservoir quality, Permeability, Porosity, Diagenesis, Compaction, Cementation, Well log analysis, Reservoir characterization — **FIGURE 2**

Eolian depositional regime showing complex stratigraphic relations between dune, interdune, playa, and alluvial deposits).

Eolian depositional regime showing complex stratigraphic, dunes, sand, sandstone, erosion, abrasion, deflation, desertification, aeolian processes, windward, leeward, cross-bedding, slip face, ripple marks, yardangs, desert pavement, sand sheets, saltation, suspension, wind velocity, dune fields, ergs, transverse dunes, longitudinal dunes, barchan dunes, star dunes, blowouts, loess, dust storms, sand storms, haboobs, desert varnish, rock pedestals, hoodoos, arches, mesas, buttes, canyons, playas, pan dunes, sand shadows, wind tails, zibars, salt flats, salt pans, quicksand, wind ripples, deflation hollows, sand seas, desert ecology, aridity, erosion control, sand mining, wind turbines, dust devils, sand spouts, desert flora, desert fauna, geologic time, eolian sediments, fossil dunes, desert pavement, ergodic hypothesis, paleoclimate, desert hydrology, aeolian transport, ventifacts, desert geology, desertification control, wind erosion, eolian landforms, sand seas, dune migration, geomorphology, desertification, atmospheric sciences, aeolian dust, eolian climate archives, eolian soil, eolian deposits, aeolian landforms, eolian geomorphology, Eolian environment, Petroleum geology, Sediment transport, Aeolian deposition, Wind-blown sediments, Dune morphology, Cross-bedding, Sand accumulation, Dust deposition, Erosion features, Wind direction, Eolian facies, Grain size distribution, Sedimentary structures, Stratigraphy, Paleoclimate, Eolian reservoirs, Reservoir quality, Permeability, Porosity, Diagenesis, Compaction, Cementation, Well log analysis, Reservoir characterization — **FIGURE 3**

This desert coast, marginal marine depositional scheme is apparently responsible for the subaerial/subaqueous confusion and controversy surrounding a number of well-known stratigraphic intervals in the western United States. Most of these have been mentioned above and are traditional hydrocarbon reservoirs for large parts of the Rocky Mountain region. To some degree, the difficulties and controversies involving these rocks have shown that the definitive separation of eolian and marine facies becomes at some point an academic exercise (Ahlbrandt and Fryberger 1982).