Geologic Map of Alaska: Intricately intruded areas of volcanic graywacke and mudstone

Intricately intruded areas of volcanic graywacke and mudstone

Unit symbol:	TKis
Age range	Tertiary or Upper Cretaceous (113 to 61.6 Ma)
Lithology:	Sedimentary
Group name:	Nonmarine to shelf sedimentary rocks

Unit is mapped in areas where numerous small hypabyssal bodies of rhyolite and dacite intrude the Ksd unit. Igneous complexes are composed of small, closely-spaced rhyolite, dacite, andesite, granite, granodiorite, tonalite, and monzonite porphyry bodies. Intrusive bodies are too small and too numerous to be mapped separately. Sedimentary host rocks are altered to erosion-resistant hornfels. A felsic hypabyssal body belonging to the complex in the southwestern part of Unalakleet quadrangle yielded a single K/Ar isotopic cooling age of 68.8±3 Ma (Patton and Moll-Stalcup, 1996)

Source map information

Source map	Patton, W.W., Jr., 2000, Unpublished data.
Symbol	Kvc
Unit name	Intricately intruded areas of Volcanic conglomerate and breccia
Description	Intricately intruded areas of Volcanic graywacke and mudstone, late Early Cretaceous (Albian)
Lithology	Sedimentary

Correlated geologic units

Label	Ksi
Description	Rhyolite and dacite, and sandstone, shale, and conglomerate deltaic deposits and intricately intruded areas of volcanic graywacke and mudstone, late Early Cretaceous (Albian)
Geologic age	Albian to Danian
Geologic setting	Sedimentary, deltaic-and-nearshore

Lithology	Form	Importance
Hypabyssal-dacite < Felsic-hypabyssal < Hypabyssal < Igneous	Dike or sill	Major
Hypabyssal-rhyolite < Felsic-hypabyssal < Hypabyssal < Igneous	Dike or sill	Major