Zhanjin Fm

The type section is located in the Zhanjin area to the north of the Jipu (Gyipu) Village, Duoma Region to the northeast of the Ritug County, Tibet. It was named by Liang Dingyi et al. in 1982. [It is indicated as the upper formation within a Huorparco Gr on the Carboniferous lexicon stratigraphic column.]

Claystone and Volcanics. Composed of grey-green and grey-black medium- and thin-bedded silty slate, feldspar-quartz sandstone, grey-green slate, many layers of intermediate-basic volcanic rocks and tuff, with a thickness of 3000 m.

"In the Southern Qiangtang terrane, the Zhanjin Formation distributes over an area of more than 100,000 km2, which mainly consists of glacial sediments transported by ice rafts (Fan et al. 2015). The Zhanjin Formation exhibit the typical features of turbidites that deposited in a deep sea basin environment (Fan et al. 2015)." (Ming Wang et al., 2019, International Geology Review, https://doi.org/10.1080/00206814.2019.1619199).

Yields abundant Gondwana fauna, including the Eurydesma fauna of bivalves. Brachiopods represented by the Ambikella-Anidanthus fusiformis assemblage; solitary corals represented by the Amplexocarinia-Cyathaxonia assemblage, whose features are similar to those of the generalized Eurydesma fauna found in Australia, Himalayan and Kashmir regions. Upper part contains Bivalves Eurydesma playfordi, E. mytiloides, E. subovalum and Schizodus occidentalis. The formation contains the Pascichnia cosmorhape-Phycosiphon assemblage.

From Carboniferous Lexicon entry: "The formation has textural and structural features of turbidites, belonging to flysch deposits. It is interpreted as a turbidites on slope of clastic margin, or flysch." However, other articles interpret portions as glacial-marine.