Wangjialeng Fm

The type section is located at Wangjialeng of Taibai County to Jiashangounao, Tuoliyuan of Liuba County, Shaanxi. It was named by Shanxi Team of Regional Geological Survey during mapping in 1965, and published by "The Regional Scale of Northwest China-Shaanxi” in 1983.

Slate. Lower member of this Formation, more than 473 m thick, is composed of dark-gray to blackish-gray carbon-bearing sandy slate and chiastolite-slate intercalated with banded fine-grained sandstone, siltstone and crystalline limestone.

Sandstone. Middle member, more than 2244 m thick, is characterized by purple sandstone and quartz siltstone intercalated with sandy slate, sandy limestone and marl.

Sandstone. Upper member, 644 m thick, is dominated by purplish-gray calcareous sandstone, of which the lower part is intercalated with bioclastic limestone.

The upper part of the Middle member yields brachiopods Acrospirifer lungmenshanensis and Euryspirifer; and the Upper member yields coral Squameofavosites.

East in the Changgou to Laogou area, south of Shanyang County, the formation has less complex outcrops with a total thickness of more than 1669 m, although the bottom is not exposed, and its lithology is dominated by yellowish-brown and grayish-green medium-bedded feldspathic quartz sandstone and siltstone, intercalated with pebble-bearing quartz coarse-grained sandstone, conglomerate and a few beds of sandy micritic dolomite. Its lower part yields brachiopod ?Acrospirifer. The lithological character is similar to that of the western Taibai area, but component lithologies are more complex, suggesting this area may be nearer to the provenance source.