Paleomagnetic results from the Sadlerochit and Shublik Mountains, Arctic National Wildlife Range (ANWR), and other North Slope sites, Alaska
Carboniferous through Triassic sedimentary units exposed in the Shublik and Sadlerochit Mountains were sampled in an attempt to obtain reliable primary magnetic components. Reliable pre-Cretaceous paleomagnetic poles from this area would greatly advance the understanding of the rotation and latitudinal displacement history of the North Slope. Carbonate rocks of the Carboniferous Lisburne Group were drilled in south-dipping units of Katakturuk Canyon, Sadlerochit Mountains, and in the north-dipping Fire Creek section, Shublik Mountains. Magnetic cleaning involved stepwise thermal demagnetization to 550/sup 0/C. Principal component analysis of the demagnetization results defines two major components of magnetization. The secondary component is steep and down (inc = 87/sup 0/), but the characteristic component (325/sup 0/C-500/sup 0/C) is reversed. The secondary magnetization postdates Cretaceous and younger folding, whereas the characteristic component was acquired before folding. The components may have recorded two phases of overprinting: a late Cretaceous into Cenozoic normal overprint and a predeformation remagnetization episode during a time of reverse polarity. However, the reverse component more likely is primary remanence. If so, it would suggest little latitudinal displacement but 40/sup 0/ of clockwise rotation with respect to North America. The Devonian Nanook Limestone, sampled in the Shublik Mountains, also reveals two major components of magnetization; however, the characteristic component is isolated at blocking temperatures greater than 500/sup 0/C and is shallower in inclination than expected from the Devonian reference pole for North America.
- Research Organization:
- Geological Survey, Menlo Park, CA
- OSTI ID:
- 6131696
- Report Number(s):
- CONF-8505215-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 69:4; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
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Stratigraphic and structural framework of ellesmerian and older sequences in Sadlerochit and Shublik Mountains, Arctic National Wildlife Refuge (ANWR), northeastern Alaska
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Related Subjects
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALASKA
ALASKAN NORTH SLOPE
CARBONATE ROCKS
DEVONIAN PERIOD
FEDERAL REGION X
GEOLOGIC AGES
LIMESTONE
MAGNETISM
MESOZOIC ERA
MISSISSIPPIAN PERIOD
NORTH AMERICA
PALEOMAGNETISM
PALEOZOIC ERA
PENNSYLVANIAN PERIOD
ROCKS
SEDIMENTARY ROCKS
TRIASSIC PERIOD
USA