: Paléoclimatologie: incised valley

geomorphological structure > incised valley

incised valley

Incised valleys are mountain-valley-like features that commonly result from river down cutting into coastal plains and continental shelves in response to marine regression. They are the key evidence to identify sequence boundary on seismic profiles and outcrops. The magnitudes of their down cutting have been used to estimate the global sea-level variations. In contrast to mountain valleys, which owe their topography to structural movements, the formation of incised valleys is primarily in response to erosional base level drops during sea-level falls. Since sea-level fluctuations are most manifested in coastal areas, they are prominent in shallow water environments, where prior depositional surfaces are subject to subaerial erosion and fluvial systems continue carving downward. As sea-level rises, the incised valleys are drowned and filled with non-marine though estuary to open marine sediments. Subsequently, the term of incised valley has been extensively used to describe outcrops. (Adapted from: https://en.wikipedia.org/wiki/Incised_valleys)

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