Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4723946 | Precambrian Research | 2009 | 19 Pages |
Abstract
There is about a 300Â Ma interval between Unit 1 volcanism at approximately 3.1Â Ga, and igneous activity represented by the Bijou Point Complex which intrude rocks of Unit 3 at about 2.7Â Ga. The basal volcanic rocks resemble MORBs whereas the young volcanic rocks are potassic and of calc-alkaline affinity. Although the rocks of the two basal units appear to have formed in or near a spreading center, the rocks of Unit 3 likely were produced in a subduction environment such as those found in island arcs or some continental margin settings. Together, the three units resemble products of a Wilson Cycle, operating between 3.1 and 2.7Â Ga, with the calc-alkaline Bijou Point Igneous Complex representing terminal volcanism. Proof or rejection of this hypothesis requires additional detailed mapping, geochemical and geochronological investigations.
Keywords
Related Topics
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Geochemistry and Petrology
Authors
H.W. Nesbitt, G.M. Young, S.A. Bosman,