ISSN:
1432-1866
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract Dolostones of the ∼1200 Ma Society Cliffs Formation within the hydrothermal zone surrounding the Nanisivik zinc deposits retain a stable characteristic remanent magnetization (ChRM) on alternating field and thermal step demagnetization. Based on the thermal data and saturation isothermal remanence analyses, the ChRM resides in pseudosingle domain magnetite and hematite. A paleomagnetic fold test favours a post-folding ChRM, and a paleomagnetic contact test, using a Franklin gabbro dike, indicates that the ChRM predates ∼720 Ma. The pole position calculated from the ChRM direction is at 168.2°E, 42.8°N (δp=4.9°, δm=6.8°), giving an age of 1095 ± 10 Ma on the well-defined “Logan Loop” portion of the North American apparent polar wander path. This age is considered to date recrystallization of the dolostone host rocks in the halo around the hydrothermal sulfide deposits. No evidence is found for a postulated Cretaceous remagnetization event in the region.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001260050270
Permalink