【摘要】 榴辉岩中绿辉石的Fe2+校正是一直存在争论的问题,它直接影响到榴辉岩p-t条件的精确评价。本文通过对南大别太湖地区和桐城地区榴辉岩中绿辉石的四种Fe2+的校正比较,依据计算的峰期变质p-t条件和岩相学研究的限定,探讨了绿辉石Fe2+的校正对温度压力计算的影响,认为电价平衡是目前较为理想的校正绿辉石Fe2+的方法,并建议为保证分析的准确性和全面性,配合使用端元组分调Fe2+法和Fe2+/Fe3+=1∶1方法。同时,根据电价平衡方法计算p-t条件,判定桐城地区榴辉岩为低温高压榴辉岩,推测其原岩为洋壳物质。更多还原

【Abstract】 Fe2+ adjustment for omphacite in eclogites has been a controversial issue for a long time,and it has apparent effects on p-t estimates for eclogites.In this paper,four kinds of Fe2+ adjustments for omphacite have been compared on the basis of the peak p-t estimates and petrologic investigations of different eclogites across the Taihu and Tongcheng areas from the South Dabie Terrane.The influence of Fe2+ adjustment in omphacite on the p-t conditions has been discussed by comparison,and the charge balance method has been recommended as the ideal one for Fe2+ adjustment in omphacite.Meanwhile,the end-member Fe2+ and Fe2+/Fe3+=1∶1 adjustment methods for omphacites should be used for cross test.Furthermore,the eclogites across the Tongcheng area have been identified as the low temperature and high pressure(LT/HP) eclogites on the basis of the peak p-t conditions,in which Fe2+ in omphacite has been adjusted by the charge balance,and the LT/HP eclogites perhaps are of oceanic origin.更多还原