Bayinxibie Gr
Type Locality and Naming
Southwestern-most Inner Mongolia. The Bayinxibie Gr was named by Li Pu in 1954. The type locality is in Bayinxibie Mountain in northwest part of Alxa Zuoqi, Inner Mongolia.
Synonym: （巴音西别群）
Lithology and Thickness
It is informally subdivided into lower and upper lithostratigraphic formations with a conformable contact between them. The lower formation is represented by east Bayinxibie section in Alxa Zuoqi, and the upper formation is represented by Zhulazhaga-Maodao section in Alxa Zuoqi and the. Lower formation, 1160 m thick, consists of marl, slate and thin-bedded quartzite, with the upper part intercalated with several intermediate-basic volcanic rock beds. Upper formation, 700 m thick, is composed of blue-grey thick-bedded dolomite, intercalated with minor yellow-grey muddy and silty slate and muddy limestone, while. The group is relatively stable both in lithological facies and thickness. The Bayinxibie Gr is over 1800 m thick.
Relationships and Distribution
Lower contact
The base of the lower formation is in conformable contact with the Takelinobo Fm of Nuorgong Gr, Changcheng System. However there may be a fault repetition or other structure problem in Bayinxibie Gr section in Bayinxibe region, but this awaits proof.
Upper contact
Schematic stratigraphic column indicates it is disconformably overlain by a Wulanhaxia Gr (not in Lexicon) of Qingbaikouan age; but Alxa column (17) for Neoproterozoic has a Haishenghala Fm of early Qingbaikouan (which might be the lower unit in that Group?)
Regional extent
Southwestern-most Inner Mongolia. The Bayinxibie Gr concentrically spreads at Bayinixibe Mt., Haisheng-Hala, Hala-Wula and Zhulazhaga-Maodao Mt. in northwest part of Alxa Zuoqi, Inner Mongolia.
GeoJSON
Fossils
The upper formation yields abundant stromatolites, such as Colonnella bayanxibiensis, Tielingella cf. tielingensis, Anabaria f., Conophyton cylindricum, C. favosum, Jacutophyton alaxaensis, Baicalia alaxaensis, Jurusania f., Inzeria f., Tungussia f., and Kussiella f..
Age
Depositional setting
Additional Information