Pseudokarst Caves in the Littoral Environment

Abstract

Rocky coastal regions can host caves produced by karst (dissolutional) processes, and caves produced by pseudokarst (non-dissolutional) processes. On limestone coasts, which are common world wide, both processes can be active and a complex interplay can result. Lava tubes, calcaerous tufa deposition, and reef growth all produce constructional caves, voids formed as the rock itself is formed. Only reef growth is an obligatory result of the marine coastal environment. Tafoni result from subaerial weathering of a variety of lithologies exposed on a cliff or steep slope, and can mimic other types of pseudokarst caves and karst caves. Talus and fissure caves result from failure of steep slopes and cliffs, themselves a result of coastal erosion which can quickly remove these pseudokarst cave types. Sea arches and sea caves are abundant on rocky coasts, as the interaction of wave dynamics and rock properties create a variety of erosional voids. Sea cave processes can overprint other cave types to produce a hybrid cave. Sea caves are likely the most common cave type in the world, but on limestone coasts, dissolutional mixing zone caves also form in great numbers, and are commonly overprinted to make abundant hybrid caves.