Jilong Fm
Type Locality and Naming
The type section lies between Jilonggunba and Zhadari, Zhuobu District, Tingri County, Tibet. It was named by Yin Jixiang and Guo Shizeng in 1976.
Lithology and Thickness
Glacial, Siltstone and Sandstone. Lower part (the Zhadari Complex Conglomerate Member) is a diamictite layer. The pebbles are poorly sorted, a few of them with scratches. Their matrix consists of gray silt, fine-grained sand and clayey materials. It contains a few brachiopods at the top; thickness ca. 30 m. Middle part (the "Siltstone Member") is dominated by dark-gray bioclastic siltstone; thickness 0.5−1 m. Upper part (the Chaya "Quartzite Member") is composed of gray, white, yellow-brown and yellow-gray thin- to moderately thick-bedded quartzose sandstone and fine-grained sandstone.
Relationships and Distribution
Lower contact
Unknown: The top is in fault contact with older Sinian−Cambrian strata; implying a thrust. Elsewhere, the bottom is in fault contact with the younger Quzon Fm (of late Visean of Early Carboniferous to Late Carboniferous) Or, at column Perm54a, implied as overlying the Gangmenqiong Gr.
Upper contact
Regional extent
GeoJSON
Fossils
Middle part (the "Siltstone Member") contains Brachiopods Lissochonetes cf. geinitzianus, Stepanoviella gracilis, Trigonotreta cf. narsarhensis, Punctospirifer jilingica, Attenuatella convexa, etc. and coral Empodesma sp.
Age
Depositional setting
It is interpreted as glacial-marine deposits.
Additional Information