Nie, Z.; Song, Z. (1985). Foraminiferal assemblage of Lower Permian Maokou'an Longge Formation in Rutog, Ngari area, Xizang (Tibet) in China. Contribution to the Geology of the Qinghai-Xizang (Tibet) Plateau in China. 17: 199–216 (in Chinese).
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Nie, Z.; Song, Z.
1985
Foraminiferal assemblage of Lower Permian Maokou'an Longge Formation in Rutog, Ngari area, Xizang (Tibet) in China
Contribution to the Geology of the Qinghai-Xizang (Tibet) Plateau in China
17: 199–216 (in Chinese)
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A perfect section of the upper Lower Permian Maokou'an Longge Formation has been investigated in Aula, Rutog County, Xizang (Tibet).The Longge Formation with its basal part covered and an exposed thickness of about 441 meters, is overlain disconformably (?) by the Lower Triassic Aula Formation containing Claraia fauna. It is composed of light-grey thick-bedded to massive bioclastic limestone intercalated with oolitic limestone and sandy limestone. Very abundant small benthic foraminifera were obtained from the limestones. The present paper deals with 26 genera and 95 species of foraminifera, among which 1 genus,28 species and 1 subspecies are new. A list of all species is given in the Chinese text. Based on its abundant taxa and vertical distribution,the Shanita-Hemigordius (Hemigordiopsis) assemblage may be established. Most abundant and best developed species of this assemblage are Shanita amosi,Hemigordius (Hemigordiopsis) renzi,H.(H.) biconcavus,Dagmarita altilis.Other important elements of the assemblage are Cribrogenerina obesa,C.vermiculata,Baisalina guizhouensis,Hemigordius parvulus.Other abundant forms include Nodosaria, Pachyphloia,Climacammina,Cribrostomum,Frondicularia,Globivalvulina and Glomospira. This assemblage occurs in association with Neoschwagerina,Colania, Verbeekina and Yabeina. Aulalina gen.nov. (Type species- Aulalina aulaensis gen.et sp.nov.)- Test consists of a round initial chamber and a second long tubular chamber which is similar to that of Glomospirella coiling irregularly around the initial chamber in different planes in the early stage,but later becoming planispiral. Rudimentary triangular septa developed in the last planispiral volution and ridge-like secondary deposits at the base of the same volution.Wall calcareous imperforate consisting of a thin dark opaque outer layer and a thick micro- granular inner layer. Remarks.-The new genus bears resemblance to genus Baisalina but differs from the latter in having secondary deposits. Locality and Horizon.- Lower Permian Maokou an Longge Formation, Rutog,Xizang (Tibet).