Julideneng Fm

The type section is located at the No. 2526 high of Jiajiquan (spring), Mori County, Xinjiang. It was named by Gao Yunsheng et al. in 1970.

Volcanics, Volcanics and Sandstone. Dominated by a suite of neritic acid−basic volcanic eruptive rocks, and secondarily by terrigenous clastic rocks. At the type section, it is composed of purple-brown and gray-green ash tuff, intermediate lithic-crystal tuff, tuff breccia, amygdaloidal basalt porphyrite, olive basaltic porphyrite, and minor porphyrite andesitic, porphyrite dacite, pophyrite plagioclasite, tuffaceous sandstone, siltstone, conglomerate and minor greywacke polymineralogic sandstone, carbonaceous mudstone and siltstone. Exposed thickness 4591 m.

Eastward to the Qijiaojing section, siltstone and fine-grained sandstone intercalated with limestone increase in the lower part, exposed thickness 5307 m. Eastward to the Liudaowan gully of Hami, the upper part is composed of clastic rock, feldspar-rich very-coarse-grained sandstone, sandy conglomerate, siltstone and increasing mudstone, intercalated with brachiopods and coral fossils, exposed thickness 2675 m. Regionally, from west to east, volcanic rocks are decreasing while terrigenous clastic rocks are increasing.

Containing Brachiopod Boxtonia, gastropods Euphemites and Omphalonema, and bivalve Ayiculopecten. Qijiaojing section lower part contains corals Bradyphyllum and Amplexus, brachiopods Dictyoclostus and Chonetes, Ammonoid Cravenoceras acutus, spore-pollen Leiotriletes, Trachytriletes, etc

It is interpreted as volcanic eruptions into neritic clastics.