The temperature estimation using garnet (Grt)-clinopyroxene (Cpx) Fe-Mg exchange geothermometers was carried out for an ultrahigh-pressure (UHP) eclogite complex in the Su-Lu terrain, eastern China. The obtained temperatures (from 600 to 900°C at 30kbar) and KD (=(Fe/Mg)Grt/(Fe/Mg)Cpx=8-13) show a wide variation and they are clearly dependent upon the jadeite-content (Xjd) of Cpx. It mainly owes to a positive correlation between fe#(=Fe2+/(Fe2++Mg)) and Xjd in Cpx. Such a phenomenon was known for Cpx with Xjd higher than 0.7 in the quartz-eclogite facies rocks, but it is more clearly recognized from omphacite to jadeite in the coesite-bearing UHP eclogite. We may need a new correction factor on Xjd to estimate the equilibrated T of UHP rocks.
No takes yet. Share an insight, caveat, or question.
Takaο Hirajima (1996) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: