CAMBRIAN SEQUENCE STRATIGRAPHY OF EASTERN YUNNAN

Field sequence stratigraphic analysis of the Cambrian strata of eastern Yunnan permits recognition of ten sequences, each with a time interval of 1-10 Ma. There are six sequences in the Early Cambrian, two in the Middle Cambrian and two in the Late Cambrian. Each sequence is subdivisible into two to five subsequences: There are a total of 27 subsequences. According to the forms of accumulation of the deposits, the relative lowstand （RL） and relative highstand （RH） and sometime condensed interval （CI） may be distinguished.The study of sequence stratigraphy has important significance for the stratigraphic correlation and boundary determination, which is manifested as follows: （1） There is dispute over the biostratigraphy of the Canglangpu Stage. As two Itype sequence boundaries exist in eastern Yunnan, the contact between the Wulongqing Member and the Hongjingshao Member is disconformable. The biozones are not complete, so the scheme of size biozones proposed by Zhou Zhiyi should be adopted. （2） The Shuanglongtan and Xiwangmiao Formations are both synchronous heteropic deposits, marked by SB 2h and SB 2i. （3） The top boundary of the Shuanglongtan Formation is marked by SB 2i, which may be correlated with the base boundary of the Loushanguan Formation. Its age may range upward into the early Late Cambrian.