Xileng Fm
Type Locality and Naming
East-central Anhui. The Xileng Fm was named by the Party of Regional Geological Survey, Anhui Bureau of Geology in 1985. The naming locality is the Xileng Village, near Shije Vollate, southwest of Chuzhou City, Anhui Province. Upper formation in Zhangbaling Gr.
Synonym:
Lithology and Thickness
The Xileng Fm is a metamorphosed volcanic rock series, predominated by quartz keratophyre, and its volcaniclastics. The rocks of the formation are mostly blackish green and grey-green in color. Lower part is dominated by quartz keratophyre and tuffaceous lava of the same kind and ignimbrite accompanied with minor brecciated tuff, tuffaceous breccia and 1-2 beds of metasilttone of phyllite, locally stratoid crystalline limestone and chert bands. Middle part is quartz keratophyre and and tuffaceous lava of the same kind, brecciated tuff and keratophyre, spilite and tuffaceous brecciated tuff lava of the same rock, occasionally sandwiched with a bed of phyllite. Both spilite and keratophyre bear vesicular and amygdaloidal structure. Upper part has a similar litho-assemblage. The formation is 2352 m thick.
Relationships and Distribution
Lower contact
Conformably on the Beijiangjun Fm.
Upper contact
It has an unconformable contact with Zhougan Fm (Sinian).
Regional extent
East-central Anhui. The formation spreads concentrically in the Zhangbaling range area, west of Chuzhou City.
GeoJSON
Fossils
Paleomicroplants are mainly species of Trachysphaeridium, Leiominuscula, Gloeocapsamorpha and Polydrosphaeridium. Through SEM, the ferruginous quartzite contains unicellular microfossils, such as species of Huroniiospora and Mixococcoides.
Age
Depositional setting
Protoliths may be a flysch
Additional Information