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Article: Paleomagnetic dating of the northern Alberta kimberlites.(Report)
- Article from:
- Canadian Journal of Earth Sciences
- Article date:
- April 1, 2009
- Author:
CopyrightCOPYRIGHT 2009 NRC Research Press. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Introduction
Pioneering work using paleomagnetism on kimberlites was first successfully done in South Africa (Jones 1968). McFadden and Jones (1977) studied five kimberlite pipes to construct the paleomagnetic pole position for Africa in Upper Cretaceous. McFadden (1977) also pioneered the thermoremanence investigation of South African kimberlites and suggested emplacement temperatures of ~300[degrees]C. Since then paleomagnetic dating has been applied in different parts of the world including Canada (Wynne et al. 1992; unpublished report of Enkin (2003) cited by Lockhart et al. 2004). Nevertheless, the technique has not been widely used and our study is the ...
<500[degrees]C for volcaniclastic kimberlites based on the common absence of thermal metamorphic indications in xenoliths and in adjacent country rock. Sosman (1938) (cited in Watson 1967) studied the thermal effects of North American kimberlite on coal inclusions and derived a temperature of 340[degrees]C. Stability fields of alteration assemblages in kimberlite pyroclastic rocks gave a lowest temperature constraint of 300-340[degrees]C (Stripp et al. 2006). Recently, Fontana et al. (2008) demonstrated that two different neighbouring kimberlite pipes in South Africa had emplacement temperatures of [less than or equal to]340[degrees]C and 260 to>