Characteristics of Cambrian-Palaeo-ordovician Strata Sequences in Zaozhuang Area
yang en-xiu 1; yang jian-min 2; sun tian-zhu 1; zhang xin-ping 1; song jia-jun 1; zhou ru-guo 1 (1.no.4 exploration institute of geology and mineral resources; shandong; weifang 261021; china; 2.jiaozhou bureau of land and resources; shandong; jia