Western boundary of Mesozoic North America

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6644801

Chamberlain, V E; Lambert, R

The line most often used to delineate the western edge of cratonic North America is the strontium isotope line. Strontium isotopes, however, differentiate, essentially, between continental crust and oceanic crust. They cannot usually distinguish between old autochthonous continental crust and old allochthonous continental crust. Geophysical parameters are often better suited to this purpose. In many places in the Western Cordillera, notably in SE British Columbia, the use of the strontium isotope line as a cratonic boundary line conflicts with other evidence, including other isotopic evidence, geological field relations, paleomagnetic evidence and geophysical data. Magnetic and gravity anomalies, conductivity, heat flow and seismic data suggest that the cratonic boundary there is approximately along the line of Kootenay Lake (117/sup 0/ W). This boundary, which is also a magnetic quiet zone, continues south into Idaho, where it is on strike with the western edge of the Idaho Batholith. Further south, the western boundary of Mesozoic North American probably lay west of the basement quiet zone, at the pre-extension western edge of the Basin and Range Province. The geophysical evidence in northern Canada suggests that the Rocky Mountain Trench and the Tintina fault mark the cratonic edge of Mesozoic North America in that region.

• Research Organization: Univ. of Alberta, Edmonton (Canada)
• OSTI ID: 6644801
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CONTINENTAL CRUST
GEOGRAPHICAL VARIATIONS
MAPPING
NORTH AMERICA
PLATE TECTONICS
COMPARATIVE EVALUATIONS
GEOLOGIC MODELS
GEOPHYSICAL SURVEYS
MESOZOIC ERA
OCEANIC CRUST
STRONTIUM ISOTOPES
ALKALINE EARTH ISOTOPES
EARTH CRUST
GEOLOGIC AGES
ISOTOPES
SURVEYS
TECTONICS
VARIATIONS
580201* - Geophysics- Seismology & Tectonics- (1980-1989)
580100 - Geology & Hydrology- (-1989)