fossil ice[¦fäs·əl ′īs]
relict subsurface ice remaining from a past age. In the early 19th century deposits of fossil ice were thought to be the buried remains of Pleistocene glaciers and névé basins. The reason for this was the discovery of the carcasses of mammoths and other extinct animals in the fossil ice in Siberia and Alaska. In the 1950’s it was established that fossil ice can be the analogue of any of the modern genetic types of subsurface ice. Most of the fossil ice was formed during the accumulation and freezing of alluvial loams by the freezing of water in the annually occurring frost clefts of the loam and is known as reveined ice.