Characteristics and genesis of the two terms mafic-ultramafic rocks in the Dabieshan

According to recent 1:50000 geological mapping and scientific research, mafic-ultramafic rocks of the Dabieshan can be classified into two terms: One is metamorphosed in Precambrian, the other is unmetamorphosed in Mesozoic. The former consists of peridotite ,eclogite, homblende rock, plagioclase amphibolite etc and the protoliths are mafic-ultramafic intrusire rocks or volcanic rocks by structure reached. The latter is composed of pyroxentie, gabbro, diorite etc, belonging to Yanshan period mafic-ultramafic intrusive rocks, cognate magam evolvution sequence .The petrology, petrochemical, geochemistry study of them indicates that there exists no ophiolite. The determination of eclogite and Yanshan period mafic-ultramafic intrusive rock of the north in the Dabieshan provided important geological basic data for recognizing structual evolvution of the Dabie orogeny .