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In the Permian geologic period, North-Central Texas was a part of the western coastal zone of equatorial Pangea, a super-continental land mass. [1] Nearby uplifts and mountainous regions, such as the Muenster Arch and Red River Uplift, the Wichita, Arbuckle, and Ouachita mountains developed by the end of the Pennsylvanian, [2] providing elevated topography to the north and east during the Permian.
As the name implies, the streams of this area have cut deep valleys with steep sided-slopes on the surrounding ridges. Some of the gorges are at least 1,000 feet (305 m) deep. Much of the area was forested at the end of the 19th century, and much of the area is owned by the Pennsylvania Bureau of Forestry.
A floodplain or flood plain or bottomlands [1] is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high discharge. [2] The soils usually consist of clays, silts, sands, and gravels deposited during floods. [3]
Sea level rose even higher in this massive transgressive event, which helped form the 300–500 ft thick Austin Chalk, around ≈89-85mya. The Austin formation consists of recrystallized, fossiliferous, interbedded chalks and marls. Exposures of Austin chalk are mainly seen in quarries, roadcuts, and stream beds where the water eroded the top soil.
An alluvial plain is a plain (an essentially flat landform) created by the deposition of sediment over a long period by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the smaller area over which the rivers flood at a particular time. In contrast, the alluvial plain is ...
Soils are the product of climate, organisms and topography, acting on parent (geologic) material over time. Thus the great diversity of geologic materials, geomorphic processes, climatic conditions, biotic assemblages and land surface ages in the United States is responsible for the presence of an enormous variety of mineral and organic soils.
An estimated 300 to 350 homes along the Potomac River in Washington County were “wholly or partially flooded.” Edison power plant in Williamsport, Maryland, after the March 18, 1936 flood ...
Fluvisol profile along Agula'e River, Ethiopia Distribution of Fluvisols. A fluvisol in the World Reference Base for Soil Resources (WRB) [1] is a genetically young soil in alluvial deposits. Apart from river sediments, they also occur in lacustrine and marine deposits. [2] Fluvisols correlate with fluvents and fluvaquents of the USDA soil ...