Geology of the Utukok-Corwin region, northwestern Alaska

Abstract

Features related to climate.______________________ Permafrost. ________________________________ Ground ice_______________________________ Microrelief features-________________________ Stratigraphy_______________________________________ Jurassic (?) and Cretaceous systems ______________ Siltstone and shale unit______________________ Torok formation and Nanushuk group un-differentiated____ _ ___-_-__-_-___________ Stratigraphic relations...____________________ Cretaceous system ______________________________ Lower Cretaceous series_____________________ Fortress Mountain formation.____________ Torok formation..._____________________ Lower and Upper Cretaceous series Nanushuk group ___________________________________ Kukpowruk formation..___-_________ Corwin formation______________________ Upper Cretaceous series Colville group______ Prince Creek formation__________________ Quaternary system..____________________________ Pleistocene and Recent._____________________ Arctic foothills province _________________ High-level terrace deposits_____-_-___ Low-level deposits-_____-_-_____-___ Arctic coastal plain province. ____________ Gubik formation.- .-_____-_____-__-Recent deposits..___________________ Coastal area west of Cape Beaufort.______ Petrography _______________________________________ Thin sections-__________________________________ PLATE 7. Index map of northwestern Alaska showing location of Utukok-Corwin region, physiographic provinces, and areas mapped from 1947 to 1953. 8. Geologic map of the Utukok-Corwin region, Alaska. 9. Generalized geologic map of the Utukok-Corwin region, Alaska. 10. Representative sections of the Kukpowruk and Torok formations. PLATE 11. Correlated generalized sections of Nanushuk group along the Kukpowruk River. 12. Correlated generalized sections of Nanushuk group along the Kokolik River. 13. Correlated generalized sections of Nanushuk group along the Utukok River. 14. Correlated generalized sections of Nanushuk group along approximate lat. 68°55' N. in 48 EXPLORATION OF NAVAL PETROLEUM RESERVE NO. 4, ALASKA, 1944-53 tive and 2 negative elements which strike east-northeast. Structural salients in 2 parts of the region may represent northeast-striking structural highs. The western structural province is characterized by northwest-striking thrust faults which alternate with southwestward-dipping sections or partial limbs of synclines. This structural pattern is the result of eastward-directed forces from the Tigara uplift, west of the area. Reflection seismic work has been done north of the Utukok River at the headwaters of the Kaolak River, and southward along the Utukok River into the southern foothills. Two areas that are structurally distinct are delineated within this region. They are separated by the major south-dipping and west-trending Carbon Creek thrust fault, which is believed to come to the surface within the Carbon Creek anticline. The northern or upper Kaolak River area includes the Torok, Kukpowruk, and Corwin formations. This shallow Cretaceous rock sequence is gently ...

New potassium-argon data on the age of mineralization and metamorphism in the Willow Creek mining district, southern Talkeetna Mountains, Alaska

“…Such data support Chapman and Sable's (1960) interpretation of northwest-southeast oriented paleoshorelines of the Nanushuk Group but differ with Smiley's (1969) interpretation of a north-south orientation in the western area. Higher energy environments, particularly the foreshore sandstones, have the best hydrocarbon reservoir potential because they have (1) the best visible porosity in outcrop, and maximum thickness (< 25 m, commonly 5 to 10 m), (2) an adjacent hydrocarbon source (marine shale), (3) lateral continuity along the paleoshoreline, and (4) a relatively stable composition owing to removal of diagenetically unstable grains under high-energy conditions.…”

“…Chapman, R. M., and Sable, E. G., 1960 Geologic field investigations during the summer of 1977 were concentrated in the southern part of NPRA, an area whose mineral resource potential is little known (fig. 7).…”

Geology and physiography of the continental margin north of Alaska and implications for the origin of the Canada Basin

“…8 or 9, and Grantz et al, 1970a). These relations are most simply explained if the Herald fault zone and its inferred onshore extension, the thrust fault system that bounds the east side of the Lisburne Hills, postdate and are superimposed across the detachment folds (see also Chapman and Sable, 1960;and Martin, 1970). The suggested superposition could have created the Chukchi syntaxis.…”

“…The character of these sequences is shown in Figure 4A Chukchi Sea. The onshore strati graphic and structural data presented in this paper include data and concepts from Alaska Geological Society (1971; Anonymous (1970); Armstrong and Bird (1976); Beikman and Lathram (1976); Bird (1978); Brosge and Tailleur (1971);Campbell (1967); Chapman and Sable (1960); Detterman et al (1975); Jones and Grantz (1964); Kameneva (1977); King (1969); Lerand (1973); Martin (1970); Norris (1977); Tailleur and Brosge (1970); Tailleur et al (1972); U.S. Geological Survey (1978);and Young et al (1976). Archipelago, where it consists of Mississippian to Jurassic rocks of mainly easterly and southerly provenance.…”

The United States Geological Survey in Alaska: Accomplishments during 1977

“…The silt unit overlies a sequence of marine and fluvial deposits that occupy valleys cut in Cretaceous bedrock (O'Sullivan and Hussey, 1960). The gravel mapped (Chapman and Sable, 1960) at an elevation of 120 to 150 m above sea level near longitude 162° W at the upper limit of the upland silt ( fig. 11) is probably an ancient beach deposit.…”