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对大别-苏鲁高压-超高压变质岩地区包括榴辉岩等8个不同岩性的变质岩石中锆石进行了151次微区原位氧同位素分析,结果表明存在明显的氧同位素不均一性,不同岩石中锆石的δ~(18)O值变化范围从-8.5‰到+9.7‰,同一岩石不同锆石颗粒间δ~(18)O值差异达2‰～12‰,在离子探针测定精度范围内,没有观察到原岩岩浆(残留)锆石和变质增生(重结晶)锆石之间明显的氧同位素组成差异,表明在高压-超高压变质作用中变质锆石基本上继承了原岩锆石的氧同位素组成.研究发现,根据变质岩的原岩时代,可以把锆石氧同位素分成2组,一组原岩年龄在19～27亿年,δ~(18)O值约为6‰～7‰,另一组原岩年龄为7～8亿年,δ~(18)O值在0～2‰。后者明显偏低的氧同位素组成表明,在形成高级变质岩的原岩岩浆中有明显的大气降水氧同位素组成的卷入,它可能和晚前寒武纪我国华南和全球范围雪球事件有关.
Oxygen isotope analyzes of 151 zircons from 8 metamorphic rocks, including eclogite and other eclogites, in the Dabie-Sulu high-pressure metamorphic area show that there are obvious heterogeneities of oxygen isotope The δ ~ (18) O values of zircons vary from -8.5 ‰ to + 9.7 ‰ in different rocks, and the δ ~ (18) O values differ from 2 ‰ to 12 ‰ in different zircons of the same rock. No significant differences in oxygen isotopic composition between the original magmatic (residual) zircons and the metamorphic (recrystallized) zircons were observed within the range of probe determination accuracy, indicating that metamorphic zircons inherited essentially in the HP-UHP metamorphism According to the original rock age of metamorphic rocks, zircon oxygen isotopes can be divided into two groups, one group of original rock age of 1.9-2.7 billion years, the δ ~ (18) O value About 6 ‰ ~ 7 ‰, and the other group of protoliths is 700 ~ 800 million years old with δ ~ (18) O values of 0 ~ 2 ‰. The latter obviously lower oxygen isotopic composition indicates that there is a significant involvement of atmospheric oxygen isotope composition in protolith magmas forming advanced metamorphic rocks, which may be related to the occurrence of snowball events in South China and the world in early Precambrian China .