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., Weber, F.R., Dochat, T.M., Miller, T.P., and Detterman, R.L., 1997, Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula: U.S. Geological Survey Open-File Report 97-866, 34 p., 1 sheet, scale 1:250,000.
Symbol Qnd
Unit name Drift, Neoglaciation, undivided
Description Includes both unsorted, nonstratified angular debris in cirques and in valleys in front of modern and recently melted glaciers and till of other Holocene moraines. Youngest neoglacial drift forms arcuate lobes of unstable and nonvegetated rubble. Earliest neoglacial drift forms vegetated teardrop- and arcuate-shaped moraines. One particularly extensive advance in the valley of Russell Creek has been dated at no more than 1060 14C cal yr BP (table 1, sample TDS-96-09A)
Lithology Unconsolidated

Correlated geologic units

Label Qhg
Description Drift, neoglacial or so-called Alaskan glaciation
Geologic age Holocene
Geologic setting Unconsolidated
Lithology Form Importance
Boulders < Coarse-detrital < Unconsolidated Glacial Major
Gravel < Coarse-detrital < Unconsolidated Glacial Indeterminate, major