Eustasy

The age of the dunal or other deposits, formed on it after the sea had begun to withdraw, in accordance with the theory of glacial eustasy, and which I have named Berardian, is, however, the crucial thing here.

Takai, F., and Tsuchi, R. 1963 The Quaternary: In "Geology of Japan," Univ. Calif. Press: 173–196 / […] From these facts, it is inferred that the main coastal terraces were probably formed due to glacial eustacy.

The range in elevation suggests that the sea level was not constant during the formation of the caves and that the rise of land – perhaps counterbalanced periodically by glacial eustacies – was probably continuous.

Although the origin of these long-term accommodation changes is difficult to assess, we conclude that basin tectonism is responsible for these changes in most of our examples. Long-term eustasy plays a secondary role, according to our analysis.

Glaciation, by oversteepening slopes, and by subsequent isostatic rebound, greatly enhances crevice cave and talus cave formation. Glacial eustasy and isostatic rebound form, and then preserve, sea caves.

In summary, because modern continental settings lack a hydrology suitable for supplying huge volumes of brine, sufficient to form a megasalt deposit, neither modern sabkhas or salinas are directly relevant to the formation of the hydrologies and eustasies needed to deposit the huge masses of ancient marine-fed subaqueous salts detailed in Chap. 5.