Pakabulake Fm
Type Locality and Naming
Kashi-Yarkand region (NW Tarim). The type section is located at the Pakabulake Ravine (E75°03′, N39°42′), about 60 km south of the county of Ulugqat, northwestern Tarim Basin in Xinjiang. It was formally named by the Regional Stratigraphic Chart Editorial Group of Xinjiang Uygur Autonomous Region (RSCEGXUAR) (1981). RSCEGXUAR (1981) firstly named this formation as the ‘Paerbulake’ Fm. It is obviously that ‘Paerbulake’ is a wrong spelling of Pakabulake, where the type section is located.
Synonym: Gao et al. (2014b) treated the Kangcun Fm and the Shanghongse Fm (upper red color) as synonyms of the Pakabulake Fm.
Lithology and Thickness
The Pakabulake Fm is characterized by a series of grey and brownish-grey mudstones, siltstones, and grey, brownish-grey, or greyish-white mudstones, siltstones, and fine sandstones. It contains fossil ostracods, foraminifers, charophytse and sporopollens. Its thickness is around 2200 m.
Relationships and Distribution
Lower contact
In the type section, the Pakabulake Fm conformably contacts with the underlying Miocene Anjuan Fm.
Upper contact
In the type section, the Pakabulake Fm conformably contacts with the overlying Pliocene Atushi Fm.
Regional extent
The formation is widely distributed to region ranging Wulukeqiati, Kangsu, Ulugqat, Atushi, and western Kashgar, northwestern Tarim Basin.
GeoJSON
Fossils
Ostracods: Cyprideis littoralis, Hemicyprinotus valvaetumidus, Cyclocypris cavernosa, Eucypris concinna, Hemiocyprinotus valvaetumidus, Limnocythere aligra, L. malus, Candona (Pseudocandona) subequalis, Ilyocypris manasensis, I. cornae, I. dunschanensis, I. errabundis, I. evidens. Foraminifers: Rotalia beccarii, Ammonia becarii, Cibicides sp..
Sporopollens: Angiopteris sp., Hymenophyllum sp., Ptoris sp., Cuprossaceae, Taxodiaccae, Taxus sp., Cycus sp., Larix (?) sp., Quercus sp., Patamogethunaceae, Adiantum sp., Ginko sp., Glyptostrobus (?) sp., Ephedra sp., Pinnus sp., Picea sp., Cedrus sp., Tusqa sp., Podocarpus sp., Tsuga sp., Coniferae, Salix sp., Betulaceae, Betula sp., Fagus sp., Quercus sp., Castamea sp., Rhus sp., Magnolia sp., Acer sp., Chenopodiaceae, Patamogetunaceae, Compositae, Hydrocharitaceae.
Age
Depositional setting
It is interpreted as a river or riverside depositional environment.
Additional Information