Tielongtan Gr

Karakorum. The Tielongtan Group was erected by Li Shuangxi et al. from the Regional Geological Survey Team under the Xinjiang Bureau of Geology in 1971. The section for the designation is in the Aksaiyi Lake southeast of the Tianshui military station along the Xinjiang-Xizang highway (provided by the Xinjiang Stratigraphic Timescale compilation group, 1981).

The Tielongtan Group is represented by gray white, gray, brown gray, purple red, break red and pink moderately thick-bedded-massive limestone and bioclastic limestone with sandstone, siltstone, clayey limestone and mudstone. The Tielongtan Gr is more than 1967 m thick. Comprises upward succession of Xiluokezong Fm (Xiloqzung Fm; limestone and marl) (269-970 m thick), Litian Fm (200-652 m thick; sandy limestone), and Dongluokezong Fm (Donglokzung Fm; of purplish-red to light-gray massive limestone, named after Dongluokezong Hill) (584-1719 m thick).

[Figure: Lower Tielongtan Group in Qianshuihu section along the Xinjiang-Xizang highway]

[Figure: Upper Tielongtan Group in Qianshuihu section along the Xinjiang-Xizang highway]

In the Aksaiyi lake, it bears bivalves (including rudists) Bournonia cf. fourtaui, Neithea (N.) sp., N. cf. guadricostata, Aritea guadrata, Chlamys (Pethopecten) sp., Cucullaea (Idonearea) sp., Radiolites sp., Pleurotomaria sp., etc.; and in the Aksayqin lake it bears ammonites Mortoniceras sp., Thomasites sp., Hemihoplites sp., Protobrissus canalicalatus, etc.