Molaoba Fm
Type Locality and Naming
The type section is located on the southern side of the Molaoba Dam to the east of the Tuoli County, Xinjiang.It was named by the Regional Geological Survey Expedition under the Xinjiang Bureau of Geology and Mineral Resources in 1966.
Lithology and Thickness
Volcanics. Purple-grey, grey-green and brown andesitic porphyry, felsitic porphyry, brecciated rhyolite and tuff, intercalated with tuffaceous sandy conglomerate. Thickness ranges 122-530 m.
Relationships and Distribution
Lower contact
Disconformable contact with the grey-black thin-bedded tuffaceous siltstone of the underlying Baogutu Fm of the Upper Carboniferous Series
Upper contact
Disconformable contact with the overlying Kujirtai Fm
Regional extent
The formation has a thickness of 1890 m at Kujirtai in the vicinity of the Molaoba Dam; and of 2136 m in the Altengyemen area to the southwest of the Yumin County. There, the effusive rocks are in an unconformable contact with the underlying Devonian System. On the southern slope of the Sarwur Mt. the formation is 300-400-m thick in the area of the Ermin County.
GeoJSON
Fossils
Plant fossils (phytolites) represented by Noeggerathiopsis sp., Calamites sp., etc.
Age
Depositional setting
It is interpreted as a continental intermediate-acidic and acidic volcanic effusive sediments.
Additional Information