Tulongguoyi Fm
Type Locality and Naming
The type section is on the lower reach of the Laba River and the banks of Tulongguoyi-Xiatan River in Mayili Mountain (83°04′E, 45°08′N), Toli County, Xinjiang. The Tulongguoyi Formation was named by No.3 Team of Xinjiang Party of Regional Geological Survey based on the 1:50 000 scale geological survey in Mayili Mountain during 1961-1963. Its name came from the Tulongguoyi River in Tuoli County, northern Xinjiang. Obruchev V.A. (1940) defined an unnamed “Upper Silurian” in Mayili Mountain. No.3 Team of Xinjiang Party of Regional Geological Survey separated the bottom from the “Upper Silurian”, and established the Laba Fm in the lower part and the Tulongguoyi Fm in the upper part. Xinjiang Compiling Group for Regional Stratigraphic Scale (1981) included the Tulongguoyi Fm in the Laba Fm, a suggestion followed by Xiao (1990). However, Xinjiang Bureau of Geology and Mineral Resources (1999) re-separated these two formations for different lithology characters. This paper follows this later distinction.
Synonym: (图龙果依组)
Lithology and Thickness
The formation is characterized by dark grayish green sericite-chlorite phyllite, siliceous phyllite and blasto-silty mudstone. In the type area, the Tulongguoyi Formation recorded thickness of 1180 m.
Relationships and Distribution
Lower contact
It rests conformably on the Laba Fm
Upper contact
It is conformably overlain by the Koksayi Fm
Regional extent
It is exposed in Mayili Mountain and Sarmus east of Mayili.
GeoJSON
Fossils
Age
Depositional setting
It is nearshore shallow-sea clastic deposits.