Sample Paper on Continental Siliciclastic successions

Continental Siliciclastic successions

Rivers, oceans seas, winds as well as the rain runoff all have the capability of carrying particles that have been washed off of eroding rocks. Such detritus (eroded materials) includes rock and mineral fragments and when the energy transporting these debris is not enough, some particles drops in the process of sedimentation forming clastic sedimentation (siliciclastic sedimentation) (Dorsey, Rebecca  and Susan  935-8). The continental siliciclastic succession is a shallow marine  to coastal plain setting that comprises of a fluvial depositional system of shoal sediments, limestone, tidal flat sediments and fluvial deposits. Siliciclastic rocks comprises of terrigenous materials that has been formed through the weathering process of the pre-existing rocks and where the carbonates are composed of sediments formed from the sea water. The clastic sediments comprises of grain and clay materials and are classified according to the grain type. Basic grain types includes the quartz, feldspar as well as the rock fragments that sediments to form quartz sandstones, arkosic sandstones and the lithic sandstones (Ryan 153-5).

How succession occurs

The sediments succession is usually continental including the alluvial red bed and other deposits. The open marine carbonates are restricted to certain stratigraphiv levels in the middle or upper formation (Kraus 45-8). Succession occurs as a result of weathering and erosion of sediments and depositional cyclicity of different order .The sedimentary cycle leaves certain clues other processes that existed and this may be justified by the various structures formed in the process that include stratification and bedding including cross bedding, rhythmic layering, graded bedding, non-sorted sediments, rock color, sole marks, raindrop marks and fossils that characterizes succession.

The development of storm currents and gravity induced flows is usually highly variable in flow and turbulence speed as well as in sediment load thus leading to the succession of internal beds that mostly reflects the evolution of other sediments.  the succession also forms as a result of the redbeds are overlain by thick layers of  evaporate which in turn are overlain by deposits of shale and sandstone. These layers so formed are the successions and in certain instances, sandstones may contain ripple marks and shale, while in other instances, sandstone and shale may contain marine fossils. What transpires is that the redbeds suggests/designates depositions in a well oxygenated place and the place was once invaded by shallow sea that evaporates in the hot arid climate forming an evaporite, and after series of transgression and regression occurs leaving continental siliciclastic successions (Sallam, Wanas, and Osman 10433 – 10445 ).

Works Cited

Dorsey, Rebecca J., and Susan M. Kidwell. “Mixed carbonate-siliciclastic sedimentation on a tectonically active margin: Example from the Pliocene of Baja California Sur, Mexico.” Geology 27.10 (1999): 935-938.

Kraus, Mary J. “Paleosols in clastic sedimentary rocks: their geologic applications.” Earth-Science Reviews 47.1 (1999): 41-70.

Ryan-Mishkin, K., et al. “Modern sedimentation in a mixed siliciclastic-carbonate coral reel environment, La Parguera, Puerto Rico.” Caribbean Journal of Science 45.2-3 (2009): 151-167.

Sallam, E., H. A. Wanas, and R. Osman. “Stratigraphy, facies analysis and sequence stratigraphy of the Eocene succession in the Shabrawet area (north Eastern Desert, Egypt): an example for a tectonically influenced inner ramp carbonate platform.” Arabian Journal of Geosciences 8.12 (2015): 10433-10458.