The age of the formation is uncertain, with estimates ranging from Toarcian to Bajocian.

Y2, Y3 and Y4 are predominantly dark shales, while Y1 and Y5 are composed of sandstones, coal beds[1] and interbedded mudstones.

The depositional environment at the time was when the Ordos Basin formed a large inland lake, surrounded by floodplains.

[2] The coal has also been explored for the production of coalbed methane.

[4] The dinosaur Lingwulong was formerly thought to have been found in this formation,[5] but the strata was later attributed to the overlying Zhiluo Formation.