Himalayan Geology, Vol. 40 (1), 2019, pp. 92-102, Printed in India
Assessment of Cambrian sequence stratigraphic style of the North China Platform exposed inWuhai division, Inner Mongolia
MUHAMMAD RIAZ1, KHALID LATIF1,2*, TEHSEEN ZAFAR3, ENZHAO XIAO1, SHAHID GHAZI4, LONG WANG1, ABDULLAH ALI ALIHUSSEIN1
1School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China
2National Centre of Excellence in Geology, University of Peshawar, Peshawar, 25130, Pakistan
3Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
4Institute of Geology, University of the Punjab, Lahore, 54590, Pakistan
Email: (Corresponding authors):khalidlatif@uop.edu.pk
Abstract: Wuhai section exposed in the North China Platform is characterized by the Cambrian stratigraphic succession, which is reflected as a package of thick depositional sequence. It is one of the most favorable sites for the sequence stratigraphic division of the Inner Mongolia Province. The exposed rock units can be grouped into Xuzhuang, Zhangxia and Gushan formations of the Miaolingian, while Changshan and Fengshan formations of the Furongian age. The Cambrian succession is in an unconformable contact with the underlying Wangquankou Group of the Mesoproterozoic age, and makes a parallel unconformity with the overlying Ordovician Yeli Formation. The cyclicity in the sedimentary facies stacking patterns shows that the strata can be grouped into six depositional sequences of the third-order level. The micritic limestone specifies deep to middle ramp facies, while the calcareous mudstone reveals the presence of condensed section having edgewise conglomerates. Non-skeletal grain facies occupy the topper positions in the Miaolingian strata, while the Furongian microbialitic bioherms are absent from the Late Miaolingian and Furongian series rocks reported elsewhere from the North China Platform. Xuzhuang Formation at its base possesses the mixed tidal flat facies which graduates into ramp-type carbonate deposits in the Zhangxia, Gushan, Changshan and Fengshan. This shift from “TST+CS+HST” to “CS+HST” indicates the change from the immature to mature phase of the carbonate platform. The facies superposition model, stratigraphic record cycle and new chronostratigraphic framework of Cambrian, along with current Cambrian sequence stratigraphic framework in Wuhai section provides a reference example for the exploration of diverse sedimentary fabrics of North-China Platform.
Key words: Cambrian, Sequence stratigraphy, Drowning unconformity, Wuhai, North China Platform.
