Inland notches: Implications for subaerial formation of karstic landforms-An example from the carbonate slopes of Mt. Carmel, Israel

•Notch formation is governed by rock properties.•An epikarst subaerial mechanism is responsible for the formation and evolution of notches.•The geomorphic course that creates notches combines chemical, physical and biogenic weathering.•The back wall of the cavity is eroded by flake weathering/exfoliation.•The formation and destruction of notches alternate in cyclical episodes, varying in time and space.

Inland notches are defined herein as horizontal “C”-shaped indentations, developed on the carbonate slopes or cliffs in the Mediterranean to semi-arid zones. The notches are shaped like half tubes that extend over tens or hundreds of meters along the stream valley slopes. In Mt. Carmel, a series of 127 notches have been mapped. On average, their height and width are 2-2.5 m but they can reach 6 m in height and 9.5 m in width. The geomorphic processes that create a notch combine chemical, mechanical, and biogenic weathering, which act together to generate initial dissolution and later flake weathering (exfoliation) of the bed, forming the notch cavity. We propose an epikarstic-subaerial mechanism for the formation and evolution of the notches. The notches are unique landforms originating from the dissolution and disintegration of the rock under subaerial conditions, by differential weathering of beds with different petrographic properties. The notches follow specific beds that enable their formation and are destroyed by the collapse of the upper bed. The formation and destruction alternate in cyclical episodes and therefore, the notches are local phenomena that vary over time and space.

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