(Russian, gal’miroliz; from Greek halmyros, salty, and lysis, disintegration), underwater erosion, a chemical minerological transformation of initial sedimentation on the ocean floor under the influence of dissolving, oxidizing, and other processes. The concept of halmyrolysis is used to explain the origin of several minerals that appear only in ocean deposits, including glauconite (green sand) and chamosite. It is also related to undersea changes in volcanic tuff leading to the formation of bentonite and other varieties of absorbent clays. The speed of the process is determined largely by the nature of the salts and gases found in the sea-water and by the rate of deposit accumulation. Places with slowly gathering deposits are particularly favorable for halmyrolysis.