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 Smith, T.E., Robinson, M.S., Weber, F.R., Waythomas, C.W., and Reifenstuhl, R.R., 1994, Geologic map of the Upper Chena River area, eastern interior Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 115, 1 sheet, scale 1:63,360, pamphlet, 19 p.
Symbol Qd2
Unit name Glacial drift
Description Heterogeneous glacial diamicton associated with subdued moraine and outwash deposits. Usually present as isolated remnants on valley floors inside limits of Qdl. Consists of poorly sorted to moderately well sorted silty gravel with variable amounts of silt, sand, and boulders. Age uncertain, but probably middle Pleistocene. Morainal crests generally wind deflated and littered with highly weathered and pitted erratic boulders
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