Geologic Map of Alaska: Unconsolidated surficial deposits, undivided

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	Richter, D.H., Preller, C.C., Labay, K.A., and Shew, N.B., 2006, Geologic map of the Wrangell-Saint Elias National Park and Preserve, Alaska: U.S. Geological Survey Scientific Investigations Map 2877, scale 1:350,000 (digital data USGS OFR 2005-1342).
Symbol	Qog
Unit name	Older glaciation deposits
Description	Drift of older glaciations. Includes lake deposits in the Chitina River valley.
Lithology	Unconsolidated

Correlated geologic units

Label	Qwu
Description	Drift, undivided, Late Wisconsin-age glaciations (Aleknagik, Brooks Lake, Farewell II, McKinley Park, Riley Creek, Donnelly, Takomahto Lake, and others)
Geologic age	Late-Pleistocene
Geologic setting	Unconsolidated

Lithology	Form	Importance
Gravel < Coarse-detrital < Unconsolidated	Glacial	Major
Boulders < Coarse-detrital < Unconsolidated	Glacial	Indeterminate, major
Sand < Coarse-detrital < Unconsolidated	Glacial	Indeterminate, major
Silt < Fine-detrital < Unconsolidated	Glacial	Indeterminate, major