干旱区生态环境知识资源中心

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. (C) 2014 Elsevier B.V. All rights reserved.