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 Mull, C.G., Harris, E.E., Reifenstuhl, R.R., and Moore, T.E., 2000, Geologic map of the Coke Basin-Kukpowruk River area, De Long Mountains D-2 and D-3 quadrangles, Alaska: Alaska Division of Geological & Geophysical Surveys Report of Investigation 2000-2, 1 sheet, scale 1:63,360. doi:10.14509/2737.
Symbol Qsu
Description Irregular blankets of massive, homogeneous, unconsolidated silt and sand largely retransported from original hillside sites to lower slopes and valley bottoms by mudflows, slopewash, and gullying. Surface is generally smooth to gently sloping and mantled by tundra and broad expanses of grass tussocks. Permafrost in valley bottoms creates poor drainage manifesting as local bogs (unit Qs).
Lithology Unconsolidated

Correlated geologic units

Label Qsu
Description Silt deposits, undifferentiated
Geologic age Pleistocene to Holocene
Geologic setting Unconsolidated
Lithology Form Importance
Silt < Fine-detrital < Unconsolidated Eolian, Loess Major
Sand < Coarse-detrital < Unconsolidated Alluvial Indeterminate, major
Peat < Unconsolidated Swamp Indeterminate, major