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., Moore, T.E., Harris, E.E., and Tailleur, I.L., 1994, Geologic map of the Killik River quadrangle, Brooks Range, Alaska: U.S. Geological Survey Open-File Report 94-679, 1 sheet, scale 1:125,000.
Symbol MDks
Unit name Kanayut Conglomerate, Stuver Member; Endicott Mountains Allochthon, Killik River Sequence
Description Thin bedded brown fine-grained quartzose and quartzitic sandstone with minor quartz- and chert- pebble conglomerate interbedded with micaceous gray, greenish gray, reddish gray and brown shale and silty shale, generally upward-fining succession; meandering stream deposit, up to 200 m thick, grades down into Shainin Lake Member.
Lithology Sedimentary

Correlated geologic units

Label Dkys
Description Endicott Group, Kanayut Conglomerate - Stuver Member nonmarine shale and quartzite
Geologic age Late-Devonian to Early-Mississippian
Geologic setting Sedimentary, deltaic-and-nearshore
Lithology Form Importance
Conglomerate < Clastic < Sedimentary Bed Major
Quartzose-sandstone < Sandstone < Clastic < Sedimentary Bed Major
Shale < Mudstone < Clastic < Sedimentary Bed Indeterminate, major