Tamqisayi Fm

The type section is located in the Qunjisayi area to the south of the Nileke County, Xinjiang. It was named by the 9^th Expedition under the Xinjiang Geological Bureau in 1982.

Volcanics and Clastics. It is divisible into the Lower, Middle, and Upper subformations. The Lower subformation is composed of purple and grey-green andesitic crystal-clastic tuffaceous lava, tuffaceous breccia and agglomerate, with a thickness of over 400 m. The lower part of the Middle subformation is known as the Sandy Conglomerate and Tuff Member, and is composed of andesitic tuff, tuffaceous breccia, sedimentary tuff, sandstone, siltstone, marl and brecciated limestone, with a thickness of 180-462 m; and the upper part of the Middle subformation is known as the Rhyolite and Basaltic Porphyrite Member, and is composed of dark-grey amygdaloidal basaltic porphyrite and dergalite, intercalated with green and yellowish-pink rhyolite and brecciated vitric tuff and black pyroxenite, with a thickness of 60-280 m. The lower part of the Upper subformation is composed of tuffaceous conglomerate, sandstone, jade-green rhyolitic mixed-type tuff, dacitic porphyry, quartz-porphyry and volcanic breccia, with a thickness of 121-207 m; and the upper part of the Upper subformation consists of interbeds of black carbonaceous siltstone, shale and marl, intercalated with calcareous fine-grained sandstone, sandstone and micrite, with a thickness of 453 m. The Lower subformation is in an effusive unconformable contact with the overlying the Middle subformation; and the Middle subformation is in a conformable or a disconformable contact with the overlying Upper subformation.

The Middle subformation yields Bivalve fossils such as Anthraconauta cf. simplex, Palaeanodonta sp., Microdonta sp., as well as Spore-pollen and Palaeanodonta. The Upper subformation yields bivalve fossils such as Palaeanodonta glossitiformis, Palaeomutella cf. subparallela, Microdonta sp., Ostracoda represented by Estheria sp.; Plant fossils (phytolites) represented by Calamites sp., Paracalamites sp., Walchia sp., Cordaites sp., etc.