depositional sequence

depositional sequence

[‚dep·ə′zish·ən·əl ′sē·kwəns]
(geology)
A major but informal assemblage of formations or groups and supergroups, bounded by regionally extensive unconformities at both their base and top and extending over broad areas of continental cratons.
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References in periodicals archive ?
"This depositional sequence likely represents a period where materials were being deposited on the floor of a lake or running river."
"Oligocene-Miocene ramp system (Asmari Formation) in the NW of the Zagros basin, Iran: Microfacies, paleoenvironment and depositional sequence." Revista Mexicana de Ciencias Geologicas, 27: 56-71.
The depositional sequence in each subbasin typically consists of (i) a thick basal coarse-grained alluvial succession that rests unconformably on older basement rock, overlain by (ii) a dark-grey, fine-grained lacustrine succession, which is overlain conformably to unconformably by (iii) an upper coarse- to fine-grained alluvial succession.
The North China plate merged with the Siberian-Mongolian Continent in the later Paleozoic, which led to the formation of the Tianshan-Yingshan Mountain zone along the northern margin and a regressive depositional sequence consisting of alluvial, fluvial, coastal and shallow marine clastic and coal deposits in the center and southern margin.
Analyses of foraminiferal assemblages contained in eight core samples reveal the paleoenvironmental history of the Paleocene Gulf of Mexico as recorded by the TLM depositional sequence. Underlying the TLM is a distributary sand-lignite sequence, representing an abandoned delta lobe.
Geesaman and Scott (1989) and Garfield and Longman (1989) divided the Fusselman into two informal units in the subsurface of the central Midland Basin, a lower Fusselman and an upper Fusselman, each of which represents a separate depositional sequence. The lower Fusselman consists of a thin (<20 feet thick) unit of oolitic grainstone in the center of the basin that becomes dominantly dolomitic mudstone, of inferred peritidal origin, in the eastern part of the basin.
This sequential arrangement corresponds to a third--order depositional sequence similar to the one described by Aigner and Bachmann (1992) for Muschelkalk facies in Germany and by Perez-Valera et al.
To meet the prerequisites of a geological structure, the model framework is based on a clear well-organized depositional sequence dividing sedimentary strata by adherence to tectonic sequences.
Oligocene-Miocene ramp system (Asmari Formation) in the NW of the Zagros basin, Iran: Microfacies, Paleoenvironmental and depositional and depositional sequence. Revista Mexicana de ciencias Geologicas, 27(1): 56-71.
The author also suggested the potash minerals "are of the same composition and depositional sequence and depth as the potash at Unity and Saskatoon, Saskatchewan", currently the location of a number of potash mines.
The simplicity of the ore veins at the Van Silver deposit has led to a remarkably consistent depositional sequence. Microscopic examination of hundreds of specimens recovered from the ore stockpile has revealed two mineralizing episodes in the stage-2 veins, which are designated stage 2a and stage 2b, as well as a third mineralizing episode, stage 3.