| 中国金伯利岩地球化学 |
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| GEOCHEMISTRY OF KIMBERLITES IN CHINA |
| More than 100 analyses of major and trace elements of kimberlites have been undertaken. Degree of contamination of analyzed kimberlites has been estimated by Si/Mg, C. I. =(SiO2 +Al2O3 + Na2O)/(MgO + 2K2O), Mg/(Mg + Fe), SiO2, Al2O3 and Na2O contents. Most of kimberlites were contaminated and their compositions in fact not represent the compositions of the magmas from which they formed. The Al2O3 and Na2O contents of kimberlites are extremely low relative to those of other alkaline ultrabasic and basic rocks. Diamond-bearing kimberlites are relatively richer in MgO, (Cr2O3 + NiO)contents and poorer in TiO2 + Al2O3 +Na2O+ K2O +P2O5 than diamond-free kimberlites.The mean abundances of compatible elements in kimberlites from China are: Cr 846ppm, Ni 69Qppm, Co 45ppm, Sc 19.96ppm Cu 156ppm, Zn 106ppm. Cr-Al, Ni-Co, Ni-Cr, Ni-V, Sc-Ti, Zn-Ti of kimberlites show positive correlations. The average and ranges of the incompatible elements of kimberlites from China are: Ba 835ppm(22.76-6030ppm), Sr 454ppm(109.7-1341ppm), Zr 308ppm (12.15-1113ppm), Nb 81ppm (12-48.72ppm), Ta 11ppm(10-18.5ppm), U 8.8ppm(0-32ppm), Th 70ppm(20-140ppm), Li 44.68ppm(2.69 148ppm), Rb 29ppm (10-60ppm). Ba-Sr, Zr-Hf, Nb-Ta, U-Th, K-Rb of kimberlites show positive correlations. |
| DONG Zhen-xin.1991.GEOCHEMISTRY OF KIMBERLITES IN CHINA[J].Acta Geoscientica Sinica,12(2):99-114. |
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