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 Csejtey, Bela, Jr., Mullen, M.W., Cox, D.P., and Stricker, G.D., 1992, Geology and geochronology of the Healy quadrangle, south-central Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1961, 63 p., 2 sheets, scale 1:250,000.
Symbol Tn
Unit name Nenana gravel
Description Poorly consolidated, buff to reddish-brown, fluvial sequence of pebble- to boulder-conglomerate and coarse-grained sandstone with interbedded mudflow deposits, thin claystone layers, and local thin lignite beds.
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