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Source map Wilson, F.H., 2011, Unpublished data.
Symbol Dkm
Unit name Kanayut Conglomerate, Middle conglomerate member
Description Mostly gray to rusty orange-weathering conglomerate, quartzite, and sandstone in cliff-forming units about 10 - 70 m thick, separated by less resistant units of shale, siltstone and impure sandstone. Conglomerate pebbles mostly of varicolored chert and white quartz, with minor amounts of quartzite, and in southernmost part of quadrangle, with abundant slate pebbles. Near south edge of quadrangle, pebbles are stretched. Quartz-chert arenite forms matrix of conglomerate and also occurs in thin to massive, partly crossbedded nonconglomerated beds that are generally gray quartzite, firmly cemented by silica, but include some brown weathering beds and irregular patches that are partly cemented by calcite. Unit assigned to Hammond terrane
Lithology Sedimentary

Correlated geologic units

Label Dkym
Description Endicott Group, Kanayut Conglomerate, Shainin Lake, middle member
Geologic age Late-Devonian
Geologic setting Sedimentary, deltaic-and-nearshore
Lithology Form Importance
Conglomerate < Clastic < Sedimentary Bed Major
Quartzose-sandstone < Sandstone < Clastic < Sedimentary Bed Major