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Based on clinopyroxene (cpx)-melt equilibrium thermobarometer, this paper deals with the calculation of the clinopyroxene-melt equilibrium temperature and pressure of basalts in Kuandian, Hannuoba and Mingxi areas, eastern China. These basalts all bear mantle xenoliths. The results indicate that the crystallizing temperature and pressure of clinopyroxene phenocrysts in alkaline basalts are commonly higher than those in subalkaline basalts and the crystallizing temperature and pressure of cpx megacrysts are higher than those of phenocrysts, which further confirms that the cpx megacrysts crystallized at higher pressure than cpx porphyritic crystals. The cpx phenocrysts at various pressures indicates that the cpx can crystallize continually along the way the magma moves up. Regression analysis shows, although the basalts bearing mantle xenoliths moved up very rapidly, heat diffusion rather than adiabatic process still occurred. The comparison of temperatures and pressures between the cpx phenocrysts and megacrysts crystallization and xenolith in alkali basalts demonstrates that host magma came deeper than the mantle xenoliths in terms of pressure and the xenoliths are therefore the upper mantle fragments captured by magma along the way up but not the source residues of the host magma as considered previously.
Based on clinopyroxene (cpx) -melt equilibrium thermobarometer, this paper deals with the calculation of the clinopyroxene-melt equilibrium temperature and pressure of basalts in Kuandian, Hannuoba and Mingxi areas, eastern China. These basalts all bear mantle xenoliths. the crystallizing temperature and pressure of clinopyroxene phenocrysts in alkaline basalts are the higher than those in subalkaline basalts and the crystallizing temperature and pressure of cpx megacrysts are higher than those of phenocrysts, which further confirms that the cpx megacrysts crystallized at higher pressure than cpx porphyritic crystals . The cpx phenocrysts at various temperatures that the cpx can crystallize continually along the way the magma moves up. Regression analysis shows, although the basalts bearing mantle xenoliths moved very very, heat diffusion rather than adiabatic process still occurred. The comparison of shows and pressures between the cpx phenocrysts and megacrysts crystallization and xenolith in alkali basalts demonstrates that host magma came deeper than the mantle xenoliths in terms of pressure and the xenoliths are therefore the upper mantle fragments captured by magma along the way up but not the source residues of the host magma as previously.