摘要
The Yishake group consists of three fragments,the upper、the middle and the lower,which is not continuouse sedimentary strata.The clastic rock member(from late devonian to early carboniferous) in the upper part of the yishake group and the basic volcanic rock member(the age focus on Sinian to Cambrian) in the lower part of the yishake group,of which strata age has obvious difference and it is in fault contact.As a unified element of rock strata,the yishake group is no longer appropriate.Being divided from the yishake group,the basic volcanic rock in the lower part is named kudi ophiolite,and its age is early Qingbaikou epoch to Early Cambrian(Qb1-∈1) in this paper.