摘要
Orbicular rocks refer to a group of rocks having orbicular structure named by von Buch in 1802. They have been found in more than one hundred localities in thirty countries. Approximately 43% of the orbicular rocks, having been reported in literature, are granitic rocks; 30% dioritic; 15% gabbroic; 8% schistic and chromititic. However, the ultramafic orbiculite has not yet been reported. In 1984, a kind of orbicular rock on
基金
Project supported by Science Foundation of the State Education Commission, PRC.
