Newly discovered garnet-barroisite schists from the Heilongjiang Complex in the Jiamusi Massif, northeastern China

摘要

Newly found garnet-barroisite schists from the Heilongjiang Complex in the Yilan area, northeastern China, are petrographically described. They are composed mainly of albite, amphibole, phengite, epidote, garnet, quartz, titanite and magnetite, with minor amounts of stilpnomelane, apatite, hematite, rutile, and ilmenite. The metamorphism of the garnet-barroisite schists are divided into three stages: pre-peak stage of the epidote-blueschist facies; peak stage of the epidote-amphibolite facies (T = 500-540 °C and P = 10-12 kbar); and retrograde stage of the greenschist facies. These results reveal a clockwise high-P/T path for the garnet-barroisite schists in the Heilongjiang Complex.