Unconsolidated surficial deposits, undivided

Unit symbol: Qs
Age range Quaternary (1.806 to 0 Ma)
Lithology: Unconsolidated
Group name: Unconsolidated and poorly consolidated surficial deposits
Unconsolidated, poorly to well-sorted, poorly to moderately well-stratified deposits; consist predominantly of alluvial, colluvial, marine, lacustrine, eolian, and swamp deposits. May include some glacial deposits. Also includes widespread glacial and periglacial deposits that consist of end, lateral, and ground moraine, outwash, rock glacier deposits, and other glacial and periglacial deposits as well as glacially scoured bedrock that may be covered with thin, glacially derived deposits. These glacial deposits are of Holocene and Pleistocene age and may include small areas of potentially latest Tertiary deposits. Map unit locally includes reworked volcanic debris as well as block and ash flows. On generalized map, shown as part of unit QTs

Source map information

Source map Detterman, R.L., and Reed, B.L., 1973, Surficial deposits of the Iliamna quadrangle, Alaska: U.S. Geological Survey Bulletin 1368-A, 64 p., 1 plate, scale 1:250,000.
Symbol Qs
Unit name Swamp deposits
Description Dark-brown organic accumulation of woody and peaty material mixed with silt and fine sand. Sedge and sphagnum peat are both present. Measured thicknesses are about 2 feet but deposits are probably much thicker than has been observed.
Lithology Unconsolidated

Correlated geologic units

Label Qsw
Description Swamp deposits
Geologic age Pleistocene to Holocene
Geologic setting Unconsolidated
Lithology Form Importance
Silt < Fine-detrital < Unconsolidated Swamp Major
Clay < Fine-detrital < Unconsolidated Swamp Indeterminate, major
Peat < Unconsolidated Swamp Indeterminate, major