Quartzite and pelitic schist

Unit symbol: PzPxyqs
Age range Devonian and older (635 to 358.9 Ma)
Lithology: Metamorphic
Group name: Pelitic schist and quartzite and mafic interbeds (Yukon-Tanana crystalline complex)
Dominantly quartzite, schistose quartzite, and quartz-mica schist; also contains subordinate gritty quartzite, chlorite schist, calc-silicate schist, marble, magnetite-biotite schist, amphibolite, and greenstone. Ranges from amphibolite to upper greenschist facies and locally retrograded to lower greenschist facies (Nokleberg and others, 1992a; Smith and others, 1994). Corresponds, in part, to the Fairbanks schist of Newberry and others (1996) of the Fairbanks mining district and surrounding areas of the southeastern Livengood and northeastern Fairbanks quadrangles (Robinson and others, 1990; Weber and others, 1992; Newberry and others, 1996) as well as a large portion of the Circle quadrangle (Foster and others, 1983). Smaller areas of exposure occur in the southern Big Delta quadrangle (Weber and others, 1978) and in the Eagle quadrangle (Foster, 1976). In the Circle quadrangle and northern Big Delta quadrangle, small exposures of gray or greenish-gray marble and gray to cream-colored dolomitic marble are included in this unit; diopside is present locally, indicating amphibolite facies metamorphism. No age control exists for these carbonate rocks

Source map information

Source map Weber, F.R., Wheeler, K.L., Rinehart, C.D., Chapman, R.M., and Blodgett, R.B., 1992, Geologic map of the Livengood quadrangle, Alaska: U.S. Geological Survey Open-File Report 92-562, 19 p., scale 1:250,000.
Symbol Zf
Unit name Fairbanks schist unit
Description Fairbanks-White Mountains area: Greenschist facies approximately 60 percent micaceous quartzite and quartz-mica schist, medium light gray, weathers light brown, fine-grained, thin- to massive-bedded, has quartz-muscovite-chlorite-albite, sparse biotite, and garnet. Unit approximately 40 percent pelitic schist, light brown to gray, fine- to medium- grained, has muscovite-chlorite, as much as 10 percent biotite, and pinhead garnets
Lithology Metamorphic

Correlated geologic units

Label PzZyqs
Description Greenschist facies muscovite chlorite schist, quartzite and phyllite [Fairbanks schist unit - undivided]
Geologic age Paleozoic to Devonian
Geologic setting Sedimentary, shallow-marine-siliciclastic
Lithology Form Importance
Quartzite < Metaclastic < Metasedimentary < Metamorphic Greenschist Major
Quartz-feldspar-schist < Schist < Metamorphic Greenschist Major
Amphibole-schist < Schist < Metamorphic Greenschist Minor
Calc-silicate-schist < Schist < Metamorphic Greenschist Minor
Marble < Metacarbonate < Metasedimentary < Metamorphic Greenschist Incidental