Abstract
Contrary to general opinion, a distinctly bimodal magmatism involving rather ordinary biotite granites and coeval basalts has been a feature of the earth’s cratons since the Early Proterozoic. Although I shall concern myself here mainly with the alkalic granites of this same environment, it is important to emphasize that they are really of small volume in relation to their calc-alkaline and essentially I-type analogues. To emphasize this point and to set in contrast the two compositional types I turn briefly to a 1988 study by Wyborn and co-workers of the 1800–1840 Ma magmatism of Australia.
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Selected References
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© 1997 Springer Science+Business Media Dordrecht
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Pitcher, W.S. (1997). Intraplate, rift-related magmatism: mainly the A-type, alkali feldspar granites. In: The Nature and Origin of Granite. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-5832-9_15
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DOI: https://doi.org/10.1007/978-94-011-5832-9_15
Publisher Name: Springer, Dordrecht
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