Continental Deposits

deposits formed on land, including continental bodies of water such as lakes and rivers. Depending on the conditions under which the original sediment was accumulated and transformed, several types of continental deposits may be distinguished: surface, or subaerial, deposits; underwater, or subaqueous, deposits; and subglacial deposits, which develop under an ice cover. Depending on the dynamics of accumulation, conditions of bedding, and general structural patterns, different genetic types of continental deposits may be identified, classified into paragenetic groups and series according to the natural combinations that they form. Especially important is the eluvial series, comprising different types of eluvium, which makes up the crust of weathering and is a product of change in rocks caused by weathering at the place of their original occurrence.

All the other types of continental deposits are included in the group of sedimentary formations proper. They develop through the redeposition of the products of the breakdown of original rocks by agents of denudation or through the accumulation of products of the vital activity of organisms. The slope series is made up of deposits that develop at the base of slopes as their upper parts are denuded. There are five genetic types of slope deposits: avalanche (cave-in) accumulations, talus, landslide accumulations, solifluctions, and diluvium. The water series includes river deposits (alluvium), proluvium (deposits by temporary streams), and lake deposits. The glacial series consists of glacial deposits proper, or moraines; glacial-river, or fluvioglacial, deposits; and glacial-lake, or limnoglacial, deposits. The wind (eolian) series includes eolian sands forming dunes, barkhans, and other relief forms as well as eolian loess. The organogenic marsh deposits that form in caves and karst cavities and the calc-sinters, stalactites, and sediments of underground rivers and lakes constitute a special group. The “technogenic” deposits created by man, for example, mining heaps, embankments, and dams, constitute a separate group. Accumulations on land of volcanic tuffs and products of their redeposition are also included among continental deposits.