There are a variety of hypotheses for the source material of the Columbia River
Flood Basalts. These include unaltered primitive mantle, MORB-type mantle, OIB
or IAB-type mantle (plume material) contaminated by crustal material, plume
material contaminated by SCLM material, ancient SCLM material, SCLM contaminated
by crustal material, heterogeneous mantle source with crustal contamination
or heterogeneous mantle source with SCLM contamination. The following few pages
look at the most popular hypotheses and how radiogenic isotope data has been
used to analyze the source of various units of the Columbia River Flood Basalts.
Abbreviations:
OIB – Ocean Island Basalt
MORB – Mid Ocean Ridge Basalt
IAB – Island Arc Basalt
SCLM – Sub Continental Lithospheric Mantle
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