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Source map Wilson, F.H., 2007, Unpublished data
Symbol Qrs
Unit name Reworked silt
Description Chiefly reworked silt, sandy silt, and bog deposits underlying a plain transitional with or slightly above areas of flood-plain alluvium of Recent age and separated from higher plains and residual 'islands' of older silt deposits by an erosional scrap 10 to 50 feet high. Polygons added to match adjoining Bethel quadrangle.
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