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., Mohadjer, Solmaz, Labay, K.A., and Shew, Nora, 2006, Digital datasets for geologic map by Wilson, F.H., Blodgett, R.B., Blome, C.D., Mohadjer, Solmaz, Preller, C.C., Klimasauskas, E.P., Gamble, B.M., and Coonrad, W.L.—Preliminary Integrated Geologic Map Databases for the United States: Digital Data for the Reconnaissance Bedrock Geologic Map for the Northern Alaska Peninsula area, Southwest Alaska: U.S. Geological Survey Open File Report 2006-1303, on-line only. http://pubs.usgs.gov/of/2006/1303/
Symbol Qaf
Unit name Alluvial fan deposits
Description Gravel, silt, and sand, commonly occur at mouth of small side canyons. Includes some colluvial deposits.
Lithology Unconsolidated

Correlated geologic units

Label Qaf
Description Alluvial fan and talus deposits
Geologic age Pleistocene to Holocene
Geologic setting Unconsolidated
Lithology Form Importance
Gravel < Coarse-detrital < Unconsolidated Colluvial Major
Boulders < Coarse-detrital < Unconsolidated Colluvial Minor
Sand < Coarse-detrital < Unconsolidated Colluvial Minor
Silt < Fine-detrital < Unconsolidated Colluvial Minor