.../4, Sec. 11, T16S, R4W (Umiat Meridian), Chandler Lake (1:250,000) quadrangle. FIG. 3 —Kuna Formation and Etivluk Group in fenster at headwaters of Kuna River. Kuna Formation (ℙMk) is depositionally overlain by Siksikpuk Formation ( R ¯ Ps ) , Otuk Formation ( J...

...(?) Permian Siksikpuk Formation. At and east of Galbraith Lake the Wahoo Limestone rests with probable disconformity on the Alapah. The base of the Alapah is exposed at only four of the localities examined. It rests on the banded limestone member of the Wachsmuth at the Sheenjek River and Galbraith Lake...

... is in the Tiglukpuk Creek–Siksikpuk River area, north of the Brooks Range mountain front, approximately 110 km (68 mi) west of the Dalton Highway ( Figure 1 ). Structures typical of the southern foothills of the central Brooks Range are well defined and exposed in this area and have not been significantly modified...

... chert of the lower Siksikpuk Formation or undivided Imnaitchiak Chert ( Mull et al., 1987 ) or Etivluk Group ( Mull et al., 1982 ) on the Picnic Creek, Kelly River, and Ipnavik River allochthons. However, high-energy deposits of the Nuka Formation persisted for part of this time interval. Permian...

... Lisburne Group (Kuna Formation, unnamed drowned shelf facies), and the Pennsylvanian-Permian Siksikpuk Formation. Major base metal sulfide deposits of the region are present only in the Kuna Formation, which in the Red Dog district comprises siliceous black shale and black chert, minor limestone...

...Charles G. Mull; E. Adams Karen; Dirk A. Bodnar; Jerome P. Siok © 1985 American Association of Petroleum Geologists. All rights reserved 1985 American Association of Petroleum Geologists Geologic mapping in the Killik River and Chandler Lake quadrangles has delineated rocks of at least...

... Osagean and again during the late Meramecian to early Chesterian. Where most tightly dated, the uppermost Kuna Formation is Chesterian, possibly early Chesterian, and the lower Siksikpuk Formation is at least in part Morrowan. Ipnavik River allochthon: Only a single diagnostic fossil collection...

... thins and as detrital sediments grade into coarser facies. Anaktuvuk Pass lies in a broad low glaciated valley near the headwaters of the John and Anaktuvuk Rivers at the crest of the Brooks Range ( Fig. 1 ). Reaching an altitude of 2,150 feet, it is one of the lowest points along the Arctic...

... of Permian and Triassic age over-lying the Lisburne Group in the northeastern Brooks Range, whereas in the north-central Brooks Range, Patton (1957) recognized the Siksikpuk Formation, consisting of shale, sandstone, and chert of Permian age overlying the Lisburne. In the northeastern Brooks Range...

... B Geographic 163.2 14.1 8.9 ChRM B Stratigraphic 154.8 10.0 13.9 ChRM B 25% unfolding 160.3 13.5 7.5 Sill Geographic 183.5 4.0 15.1 Siksikpuk Geographic 189.1 44.0 18.2 Siksikpuk 35% unfolding 210.0 28.9 13.2 ChRM A Geo. +70...

...R. C. Crane © 1985 American Association of Petroleum Geologists. All rights reserved 1985 American Association of Petroleum Geologists The foothills area of the Brooks Range thrust belt in the area between the Itkillik River and the Etivluk River is composed dominantly of shallow, thrusted...

... of similar age 3 within the region by granitic detritus and rocks deposited under active and varied conditions. Its local juxtaposition with formations of the other successions gives evidence that gross structural dislocations have taken place. The unit is here named the Nuka Formation after the river...

... ) to the northwest of Red Dog ( Fig. 1 ). Small beds and disseminations of barite also appear higher in the Red Dog stratigraphic section as well as regionally in the Brooks Range within gray and green shales of the Permian Siksikpuk Formation and within black shales of the Triassic Otuk Formation ( Young, 2004...

... Mississippian to Lower or Middle Pennsylvanian Kuna Formation, which is the main host of barite and Zn-Pb-Ag mineralization, the Pennsylvanian to Lower Triassic Siksikpuk Formation (siltstone, shale, chert: Mull et al., 1982 ), Lower Triassic to Middle Jurassic Otuk Formation, and the lower Cretaceous...

... Pass; BA, axis of Barrow arch; C, Chandler Lake; CBR, central Brooks Range; DA, axis of Doonerak anticline; D, Mount Doonerak; F, Falsoola Mountain; I, Itkillik Lake; NE, northeastern Brooks Range; NF, North Fork Koyukuk River; P, Prudhoe Bay; S, Shainin Lake; SS, Savioyok synclinorium; W, Wiseman; WL...

... was established as the type section for the Nuka Formation ( Tailleur and Sable, 1963 ), a map unit in northern Alaska distinguished by arkosic rocks and extending from the west coast to the Anaktuvuk River in the central foothills. The 6,500-ft section at Nuka Ridge was subdivided into 13 members on the basis...

... associated sulfides ( Fig. 4 ). All known stratiform barite deposits in the Red Dog district lie at the boundary between the Kuna Formation and overlying Pennsylvanian to Permian Siksikpuk Formation ( Fig. 3 ). The upper part of the Kuna Formation is late Meramecian to early Chesterian age (~340–330 Ma...

... chert, and gray calcareous radiolarite (limestone); in the Siksikpuk Formation are gray shale, maroon, red, and green siltstone, and gray chert; in the Otuk Formation are gray and black shale and gray chert; in the Okpikruak Formation are gray to black mudstone, graywacke, and polymictic conglomerate...

... allochthonous sheets, three of which have been subject to regional and detailed structural analysis. The lowermost of these is the Endicott Mountains allochthon, which is overlain by the structurally higher Picnic Creek and Kelly River allochthons. Each individual allochthon is itself internally imbricated...