Coastal Karst

In storm-wave environments at high latitudes, mechanical wave action plays a dominant role over bioerosion and -corrosion in the shaping of coasts, while biological and chemical processes are dominant in coastal karst at mid- and low-latitudes. The related coastal landscape is therefore characterized by landforms that are mainly originated by chemical and biological weathering, such as notches, karren, tidal pools, and “black phytokarst.” They develop mainly in the intertidal and nearshore zone, where these processes are focused (Trudgill, 1985). Even if the debate on the relative contribution of the different processes on coastal limestones is far from being solved (Spencer, 1988), they produce well-defined erosional features. Sometimes the shape and distribution of coastal landforms are closely related to past sea levels and they can be considered as inherited karst morphologies, such as fossil tidal notches (Antonioli et al., 2018). The analysis of seawater and biokarst effects on coastal limestones involves karstologists, geomicrobiologists, geomorphologists, biologists, and geologists (De Waele and Furlani, 2013). This causes the overlap of terms used in different fields of work and the nomenclature is consequently characterized by different words indicating similar landforms and/or processes.