Diluvium

Diluvium, a term formerly given by geologists to those strata which they believed to have been formed by the Deluge, and more particularly to the boulder clay. The altered opinions as to the origin of these beds have caused the word to fall into disuse in Britain. It is still used on the Continent, however, not in its original sense, but simply as a general term for the glacial and fluvio-glacial accumulations of the Pleistocene system. When the adjective—diluvial—is employed by modern writers, it is to characterise those accumulations of gravel or angular stones which have been produced by sudden or extraordinary currents of water.