Pelitic schist and metavolcanic rocks of Tukpahlearik Creek

Unit symbol: DOtp
Age range Devonian to Ordovician (485.4 to 358.9 Ma)
Lithology: Metamorphic
Group name: Metasedimentary and metavolcanic rocks of Tukpahlearik Creek, undivided
“Greenish-gray, green, or gray, fine- to medium-grained chloritic quartz schist and siliceous chlorite schist * * *” that locally includes “* * * intercalated masses of dark green metabasite, mafic dikes, mafic extrusive rocks and white metachert. Mafic rocks form resistant outcrops up to 100 meters in diameter and sometimes have associated lenses of white ribbon metachert as much as 30 m thick. Metachert occurs in cm thick beds with crenulated chloritic partings. Metachert lenses or blocks also occur in pelitic schist independent of metabasite” (Karl and others, 1989a)

Source map information

Source map Karl, S.M., Dumoulin, J.A., Ellersieck, Inyo, Harris, A.G., and Schmidt, J.M., 1989, Preliminary geologic map of the Baird Mountains and part of the Selawik quadrangles, Alaska: U.S. Geological Survey Open-File Report 89-551, 65 p., 1 sheet, scale 1:250,000.
Symbol DOtpg
Unit name Pelitic schist and greenstone of Tukpaklearik Creek
Description Green and gray pelitic schists identical to the schist of unit DOtp with intercalated masses of dark green metabasite, mafic dikes, mafic extrusive rocks and white metachert.
Lithology Metamorphic

Correlated geologic units

Label DOtpg
Description Pelitic schist and greenstone of Tukpaklearik Creek
Geologic age Ordovician to Devonian
Geologic setting Undivided
Lithology Form Importance
Pelitic-schist < Metaclastic < Metasedimentary < Metamorphic Greenschist Indeterminate, major
Greenstone < Metaigneous < Metamorphic Greenschist Minor
Metavolcanic < Metaigneous < Metamorphic Greenschist Minor