A factor analysis study of the major element geochemistry of granitic rocks
A Varimax-rotated R-mode factor analysis was performed on a collection of 195 whole-rock major element chemical analyses of granitic rocks, mainly Finnish. Factor loadings with corresponding eigenvalues and communalities were computed separately for 3 to 6 factors. The rapakivis, the non-rapakivis a...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Geological Society of Finland
1977-12-01
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Series: | Bulletin of the Geological Society of Finland |
Online Access: | http://www.geologinenseura.fi/bulletin/Volume49/sgs_bt_049_2_pages_143_150.pdf |
Summary: | A Varimax-rotated R-mode factor analysis was performed on a collection of 195 whole-rock major element chemical analyses of granitic rocks, mainly Finnish. Factor loadings with corresponding eigenvalues and communalities were computed separately for 3 to 6 factors. The rapakivis, the non-rapakivis and the combined group of all the granitic rocks were each studied individually. The results show that, in contrast to the other granites, the rapakivis form a fairly homogeneous group with pronouncedly high mutual correlations between the components. A factor analysis, therefore, reveals one single factor with a very high eigenvalue. This factor is designated the femic factor on the basis of the most important participating components. In other granitic rocks three main factors emerge; these are termed the femic, the one-alkali and the biotite factor, respectively. The existence of the one-alkali factor reflects the even stronger negative correlation of Na2O and K2O in the non-rapakivis compared with the rapakivis. |
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ISSN: | 0367-5211 1799-4632 |