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Columbia River volcanism - The question of mantle heterogeneity or crustal contaminationIt is found that, although crystal fractionation played an important role in producing the chemical characteristics of Columbia River Province basalts displaying a wide range of chemical and isotopic compositions, the isotopic variability calls for the involvement of at least two isotopically distinct components. The major and trace element characteristics of the main volume of the basalts are not consistent with a metasomatized mantle source region, and the presence of a primordial mantel component is not supported by the chemical data. Models of simple binary mixing between a primary magma and Precambrian sialic crustal materials, while satisfying the observed Nd and Sr isotopic variations, fail to account for major trace element abundances. The combination of crustal assimilation and fractional crystalization is found to give a superior fit to the compositional data.
Document ID
19820036628
Document Type
Reprint (Version printed in journal)
Authors
Carlson, R. W. (California Univ. La Jolla, CA, United States)
Lugmair, G. W. (California Univ. La Jolla, CA, United States)
Macdougall, J. D. (California, University La Jolla, CA, United States)
Date Acquired
August 10, 2013
Publication Date
December 1, 1981
Publication Information
Publication: Geochimica et Cosmochimica Acta
Volume: 45
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF EAR-78-24060
CONTRACT_GRANT: NGL-05-009-150
CONTRACT_GRANT: NSF EAR-80-09231
Distribution Limits
Public
Copyright
Other