Kanayut Conglomerate and Noatak Sandstone, undivided

Unit symbol: MDegk
Age range Lower Mississippian and Upper Devonian (382.7 to 346.7 Ma)
Lithology: Sedimentary
Group name: Kanayut Conglomerate and Noatak Sandstone, undivided (Endicott Group)
Kanayut Conglomerate is one of the most widely exposed units of the Endicott Group. Nilsen and Moore (1984) locally divided it into three formal members (in ascending order): the Ear Peak, Shainin Lake, and Stuver Members. It is also commonly mapped as an undivided unit with the Noatak Sandstone. Kanayut Conglomerate has been mapped across the breadth of the Brooks Range, from the east end, by Brosgé and others (1962), to the westernmost Brooks Range, by Nilsen and Moore (1984). Where Kanayut Conglomerate and Noatak Sandstone are mapped undivided, the lower marine part of section corresponds to the Noatak Sandstone and upper parts of section represent the Kanayut Conglomerate. The lowermost member, the Ear Peak, is a sequence of fining-upward fluvial cycles of conglomerate, sandstone, and shale as thick as 1,160 m, deposited by meandering streams. The Shainin Lake Member is a sequence of fining-upward couplets of conglomerate and sandstone as thick as 530 m, deposited by braided streams. The Stuver Member is a sequence of fining-upward fluvial cycles of conglomerate, sandstone, and shale as thick as 1,300 m, deposited by meandering streams. Mull and others (1987b) suggest that the proportion of conglomerate decreases southward in the Kanayut Conglomerate. Metamorphic grade increases towards the metamorphic core of the Brooks Range (Central Belt of Till and others, 2008a). Age control based on plant fossils, largely of Late Devonian age, but including Early Mississippian plants. Noatak Sandstone described below where it is mapped separately

Source map information

Source map Mull, C.G., and Werdon, M.B., 1994, Generalized geologic map of the western Endicott Mountains, central Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Public-Data File 94-55, 1 sheet, scale 1:250,000.
Symbol MDk
Unit name Allochthonous Rocks, Endicott Mountains Allochthon, Key Creek and Ivotuk Hills sequences, undivided; Kanayut Conglomerate
Description Thick succession of gray to brown weathering quartzitic sandstone and minor quartz- and chert-pebble conglomerate, forms highest peaks in western Endicott Mountains.
Lithology Sedimentary

Correlated geologic units

Label Dky
Description Endicott Group, Kanayut Conglomerate
Geologic age Frasnian to Tournaisian
Geologic setting Sedimentary, continental
Lithology Form Importance
Conglomerate < Clastic < Sedimentary Bed Major
Quartzose-sandstone < Sandstone < Clastic < Sedimentary Bed Indeterminate, major