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, 19 p., 1 sheet, scale 1:63,360.
Symbol Qd3
Unit name Glacial drift
Description Heterogeneous glacial diamicton in moraines and minor glaciofluvial deposits. Drift bodies and moraines are partially subdued and locally exhibit hummocky, ice-stagnation topography. Natural exposures and hand-dug pits reveal poorly sorted silty gravel and moderately well sorted, sandy gravel with variable amounts of boulders and cobbles. Less extensive than Qd2 but more extensive than Qd4. Age uncertain, but probably middle to late Pleistocene
Lithology Unconsolidated

Correlated geologic units

Label Qew
Description Glaciations older than Late Wisconsin; Mak Hill, Eklutna 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