Description
In general, the deposits associated with both alpine glaciers and continental ice sheets are similar. Both deposit their eroded debris in their downstream portions or as the melt back or “retreat” that refers to the front or outer edge of the ice, not to a change in the direction of movement. The glacier is still moving downward or outward by the pull of gravity and the weight of the overlying snow. Glaciers are powerful enough to carry tiny and huge rock debris, and when they drop it, the ice drops it indiscriminately. Thus, material deposited by ice is unsorted or mixed in size. This non-sorted material is called TILL. The importance of glacial sediments can be gauged from the fact that 10 percent of the Earth’s land surface currently is covered by glacier ice. Glacier ice has left a complex, often patchy, record of deposition on land, and offshore has contributed substantially to the buildup of continental shelves. In earlier geological history, the Earth experienced several continental-scale glaciations, some of them even more extensive than those of the Quaternary Period. Glacial deposition is intimately associated with a wide range of other processes, including fluvial, mass flowage, eolian, lacustrine, and marine.
Glacial Process Sedimentology examines the global till literature and experimental and laboratory-based assessments of subglacial processes, in addition to the theoretical constructs that have emerged from process sedimentology over the past century. It critically reviews the major subglacial till forming processes as presently understood by glacial researchers and define the parameters within which tills are produced and reconcile them with sedimentary end members. Drawing on a wide range of knowledge bases; it describes contemporary laboratory and modeling experiments on till evolution and procedures for measuring damage signatures in glacial deposits. Glacial sediments are comprehensively described and characterized, enabling the glacial stratigraphy for the area to be proposed.
