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Source map Wilson, F.H., 2008, Unpublished data.
Symbol Qum
Unit name Unnamed glacial deposits -- moraine
Description Loop and recessional moraine, composed chiefly of glacial and glaciofluvial materials. Extensively mantled by colluvium, silt, muck, and peat. Moraine topography, where recognizable is much subdued and modified.
Lithology Unconsolidated

Correlated geologic units

Label Qmi
Description Illinoian glaciations
Geologic age 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