The Effect of Solvent Motion on Limestone Solution

Abstract

A series of simple experiments with dilute HC1 on calcite crystals and small limestone blocks demonstrates that agitation and motion of solvent flow are positive factors of considerable importance in limestone solution. The origin of sea-level nips in carbonate rocks is then examined, and it is postulated, mostly on empirical grounds, that a state of slight undersaturation in $$CaCO_{3}$$ occurs from time to time in coastal marine waters and that the resulting limestone solution is greatly magnified in the strongly agitated wave zone, thereby producing the nip. The origin of limestone caverns is then discussed, and it is shown that, because a limestone aquifer can aptly be compared to an integrated system of tubes or conduits, the flow velocities of ground water vary markedly in different members of the system. From the principle that the greater the flow velocity, the greater the rate of solution, it is suggested that differential solution commensurate with velocity takes place, causing preferential conduit enlargement and thereby the formation of caverns. The expanding capacity of the ground-water reservoir resulting from continued enlargement of the member conduits brings with it a steady fall in the water table and an accompanying draining of conduits. This is thought to be a possible explanation of the development of many two-cycle caverns.