Paleomagnetic results from early Eocene intrusions, north-central Montana: Implications for north America apparent polar-wandering

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL007i007p00541· OSTI ID:5242597

Diehl, J F; Beske-Diehl, S; Beck, Jr, M E; Hearn, Jr, B C

Paleomagnetic poles have been determined from two Early Eocene igneous centers located in the north central Montana alkali province. The mean paleomagnetic pole for the Highwood Mountains lies at 81.2 /sup 0/N, 167.3 /sup 0/N (N=29; ..cap alpha../sub 95/=7.1; k=15.4) while the corresponding pole for the Bearpaw Mountains is located at 80.5 /sup 0/N, 198.4 /sup 0/E (N=18; ..cap alpha../sub 95/=5.8; k=37.0). Combining these results with studies on Eocene rocks from Wyoming, gives a reference pole located at 81.7 /sup 0/N, 171.2 /sup 0/E with a circle of 95% confidence of 4.4 /sup 0/4. This data, when compared to other early Tertiary results, the Cretaceous stillstand pole and the well grouped mid-Tertiary poles from the continental interior, suggest that for the period 120 to 15 m.y.B.P. apparent polar-wandering for North America occurred as a succession of rapid shifts of the geomagnetic pole separated by periods of stillstand.

• Research Organization: Michigan Technological University, Houghton, Michigan 49931
• OSTI ID: 5242597
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 7:7; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
CENOZOIC ERA
GEOLOGIC AGES
GEOMAGNETIC FIELD
INTRUSION
MAGNETIC FIELDS
MAGNETISM
MONTANA
NORTH AMERICA
ORIENTATION
PALEOMAGNETISM
POLAR REGIONS
ROCKY MOUNTAIN REGION
TERTIARY PERIOD
USA