Jiufotang Fm

Its base is a disconformable contact marked by green silty shale and gray green shale with conglomerate cemented by sandy matters and arkose is distinguished from the underlying Yixian Fm of gray dacitic rhyolitic volcanic breccia.

Its top is bounded by the conformable appearance of coal seams at the base of the Fuxin Fm.

The present formation is widespread in the Yanliao region. It varies considerably both in lithology and thickness. In the Qinghe area, the lower part of the formation is represented by gray white sandstone with sandy shale and thin-bedded coal and oil shale and solid bitumen; the middle part blue gray sandy shale with oil shale, bearing 6 mineable coal beds; while the upper part black shale with sandstone and small amounts of conglomerate, with a thickness of 1500 m. In Qidaoquanzi of Chaoyang, the formation is dominated by gray white, gray yellow and gray green sandstone and conglomerate and gray black shale, oil shale, with a thickness of more than 611 m. In Ganzhao of Kazuo, the lower part of the formation is dominated by conglomerate and sandstone with shale; while the upper part by sandstone and shale with conglomerate, with a thickness of 1699 m. The Jiufotang Formation is 206-2685 m thick in west Liaoning, 300-700 m in the Tieling-Faku area; 1403 m in east Liaoning, 1249-4287 m in south Liaoning, 76-2848 m in north Hebei, 60-2917 m in the North China plain. It is called the Nierku Fm in east Liaoning, the Pulandian Fm in south Liaoning, the Xiguayuan Fm in north Hebei, and the Lincheng Fm in the North China plain. In west Liaoning and north Hebei, it lies conformably under the overlying Fuxin Fm and the Qingshila Fm, respectively. In the Jiufotang-Yixian area, it contains oil shale and coal.

"It can be correlated with the Chengzihe Fm because [brackish-water bivalve] Sphaerioides yixianensis is also found in the Dongdaling Fm, which approximately corresponds to the Chengzihe Fm and Muling Fm of the Jixi Group. In addition, both, the Jiufotang Fm and Chengzihe Fm, yield the Pteridiopsis e Nilssonia sinensis flora assemblage." [modified quote from Kosenko et al., 2021]