The Mackenzie River magnetic anomaly, Yukon and Northwest Territories, Canada-Evidence for Early Proterozoic magmatic arc crust at the edge of the North American craton

Tectonophysics
By:  and 

Links

Abstract

We characterize the nature of the source of the high-amplitude, long-wavelength, Mackenzie River magnetic anomaly (MRA), Yukon and Northwest Territories, Canada, based on magnetic field data collected at three different altitudes: 300 m, 3.5 km and 400 km. The MRA is the largest amplitude (13 nT) satellite magnetic anomaly over Canada. Within the extent of the MRA, source depth estimates (8–12 km) from Euler deconvolution of low-altitude aeromagnetic data show coincidence with basement depths interpreted from reflection seismic data. Inversion of high-altitude (3.5 km) aeromagnetic data produces an average magnetization of 2.5 A/m within a 15- to 35-km deep layer, a value typical of magmatic arc complexes. Early Proterozoic magmatic arc rocks have been sampled to the southeast of the MRA, within the Fort Simpson magnetic anomaly. The MRA is one of several broad-scale magnetic highs that occur along the inboard margin of the Cordillera in Canada and Alaska, which are coincident with geometric changes in the thrust front transition from the mobile belt to stable cratonic North America. The inferred early Proterozoic magmatic arc complex along the western edge of the North American craton likely influenced later tectonic evolution, by acting as a buttress along the inboard margin of the Cordilleran fold-and-thrust belt.

Study Area

Publication type Article
Publication Subtype Journal Article
Title The Mackenzie River magnetic anomaly, Yukon and Northwest Territories, Canada-Evidence for Early Proterozoic magmatic arc crust at the edge of the North American craton
Series title Tectonophysics
DOI 10.1016/j.tecto.2008.09.006
Volume 478
Issue 1-2
Year Published 2009
Language English
Publisher Elsevier
Description 9 p.
First page 78
Last page 86
Country Canada
Other Geospatial Yukon Territory, Northwest Territories
Google Analytic Metrics Metrics page
Additional publication details