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ratio is thus the ratio of the data spread in the direc- rocks driven by changes in source magma compo- Hesselbo, S.P., and Parkinson, D.N., eds., Sequence
tion of the longer eigenvector to that in the direction sition or shallow-crustal differentiation?: Geo- Stratigraphy in British Geology: Geological Soci-
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10 GSA Today | August 2020