BULLETIN OF THE CHINESE ACADEMY OFGEOLOGICAL SCIENCESSERIES XVol.2 No. 1
CONTENTSCambrian-Ordovician Boundary and Their Related Trilobites in theHangula Region,W.Nei Monggol Lu Yanhao,Zhou Zhiyi and Zhou Zhiqiang 16
Tectonjsm During Metallization of Dadaoerji Chromite Deposit inNorthwest China Dong Xianyang and Li jinming 37
A Preliminary Study on the General Tectonic Characters and Evolu-tion of North Qilian Mts Zhou Liangren,Qin Keling and Zhang Zhengxiang 51
The Characteristics of the Weiya Intrusive in Chinese Tian Shan,with a Discussion on Its Mode of Formation Li Xianzi 62
X-Ray Powder Research on Cation Composition and Distribution ofChrome Spinellides Xu Peicang,Li jingxian and Zhang Xiaoyun 72
Olivine Geothermometer Xia Linqi 82
Late Cretaceous Ostracods from the Yabrai Basin,Nei Monggol andTheir Stratigraphic Significance Qi Hua 98
Middle and Upper Ordovician Stratigraphy at Taoqupo,Yaoxian,Shaanxi and Its Correlation Fu Lipu 111
The Establishment of a New Family Trypanoporidae and Its Signifi-cance Li Yaoxi 118