Nenana Gravel

Unit symbol: Tng
Age range Tertiary, Pliocene and upper Miocene (11.62 to 3.6 Ma)
Lithology: Sedimentary
Group name: Nenana Gravel
Yellowish-gray to reddish-brown well-sorted, poorly to moderately consolidated conglomerate and coarse-grained sandstone containing interbedded mudflow deposits, thin claystone layers, and local thin lignite beds widely distributed on the north side of the Alaska Range. Unit is more than 1,300 m thick and moderately deformed (Csejtey and others, 1992; Bela Csejtey, Jr. written commun., 1993)

Source map information

Source map Pewe, T.L., Wahrhaftig, Clyde, and Weber, Florence, 1966, Geologic map of the Fairbanks quadrangle, Alaska: U.S. Geological Survey, Miscellaneous Investigations I-455, 5 pages, 1 sheet, scale 1:250,000.
Symbol Tn
Unit name Nenana Gravel
Description Buff to reddish-brown poorly consolidated pebble to boulder conglomerate and coarse sandstone, with interbedded mudflow deposits, thin claystone layers and local thin lignite beds. Maximum thickness is 2000 feet.
Lithology Sedimentary

Correlated geologic units

Label Tn
Description Nenana Gravel, Pliocene and Miocene
Geologic age Late-Miocene to Zanclean
Geologic setting Sedimentary, continental
Lithology Form Importance
Conglomerate < Clastic < Sedimentary Bed Major
Sandstone < Clastic < Sedimentary Bed Indeterminate, major
Mudstone < Clastic < Sedimentary Bed Minor
Claystone < Mudstone < Clastic < Sedimentary Bed Minor
Lignite < Coal < Sedimentary Bed Incidental