Cameng Fm
Type Locality and Naming
The type section is located in the Tuotara area to the north of the Jipu (Gyipug) Village, Duoma District, Ritu County, Tibet. It was named by Liang Dingyi et al., in 1982. . [It is indicated as the lower formation within a Huorparco Gr on the Carboniferous lexicon stratigraphic column.]
Synonym: Chameng Fm (spelling)
Lithology and Thickness
Glacial. It is formed by a suite of sandstone and sandy slate series, in which the sandstone contains basic volcanic rock (diabase) and diamictite (pebbled slate). The thickness varies greatly, but all >500 m. The pebbled slate and pebbled siltstone are characterized by: in the gray-brown clayey or silty matrix, there are unharmoniously scattered various types of conglomerates, with the diameter being 600 cm maximum, and generally 1−3 cm. The conglomerates are composed of granite, volcanic rocks, quartzite, conglomerate, schist, etc. Glacial striations, striated planes or pits are found on the surface of some conglomerates. The pebbled slate and pebbled siltstone do not show stratification by themselves (often intercalated with sandstones and conglomerates of horizontal or cross stratification). Thickness exceeds 500 m.
Relationships and Distribution
Lower contact
Unconformable contact with the underlying lower Carboniferous “Nazha Fm” (not in Carboniferous Lexicon)
Upper contact
Conformably overlain by the Zhanjin Fm
Regional extent
From Carboniferous Lexicon entry: "It is widespread in the Indo-Pakistan subcontinent and around Domar to Longmuco of the Qangtang area, Tibet, best exposed at Cameng, Gyipug (Jipu) Village, Domar District, Rutog County, Tibet."
GeoJSON
Fossils
No fossil has been found in the formation
Age
Depositional setting
It is interpreted as glacial-marine sediments, most typical of the Gondwana facies
Additional Information
The lithological characteristics of the formation are similar to those of the agglomeratic slate in Kashmir, of the Zhadari Complex Conglomerate Member of the Jilong Fm in the Himalayan region, and of the pebbled slate from the lower part of the Pangduo Gr in the Lhasa area.