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ZHANGJIAKOU FORMATION IN WESTERN LIAONING PROVINCE, CHINA: Its Geologic Significance |
YANG Ya-jun1, HUANG ZHi-an2, SHAN Xie-dong2, DONG Wan-de2, WANG Zhong-jiang2, LIU Wen-hai2, PAN Yu-qi2 |
1. Shenyang Institute of Geology and Mineral Resources, Shenyang 110033, China; 2. Liaoning Institute of Geological Exploration, Dalian 116100, China |
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Abstract The Zhangjiakou formation in Western Liaoning, which was discovered and established on the basis of 1:250 000 mapping of Jinzhou and Jianping sheets by regional geologic investigation, is mainly distributed in the east margin of Jinlingsi-Yangshan basin, the west margin of Beipiao basin, Sijiazi basin, Tieyingzi basin and Sanshijiazi basin in Lingyuan along a NE-trending fracture zone. The formation consists mainly of pyroclastic breccia, rhyolite and tuff, unconformably overlying the Tuchengzi formation (or older strata) and underlying Yixian formation. It was formed in the transitional environment of compressional orogeny and extensional structure, as the result of the transition of Paleo-Asian tectonic domain and the Marginal-Pacific mobile belt. The formation belongs chronologically to Late Jurassic epoch.
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Received: 14 January 2005
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