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The Biogeography And Geomorphology Of The Niobrara River Valley Near Valentine, Nebraska., Paul J. Hearty

Student Work

Within the study area located near Valentine, Nebraska, the Niobrara River is deeply entrenched in Tertiary siltstones and sandstones, and covered with Pleistocene and Holocene eolian deposits of sand and loess. The 100 m depth of the valley reflects the entrenchment. Periods of equilibrium of the river are indicated by the numerous benchlands that lie within and adjacent to the valley. Mass wasting in the forms of landslides and creep significantly alter the form of these terracelands when it is combined with the shifting of the river and saturation by groundwater. Many of the terraces have been correlated with climatic …