Middle Jurassic Plant Diversity and Climate in the Ordos Basin, China

The Ordos Basin is one of the largest continental sedimentary basins and it represents one major and famous production area of coal, oil and gas resources in China. The Jurassic non-marine deposits are well developed and cropped out in the basin. The Middle Jurassic Yan'an Formation is rich in coal and contains diverse plant remains. We recognize 40 species in 25 genera belonging to mosses, horsetails, ferns, cycadophytes, ginkgoaleans, czekanowskialeans and conifers. This flora is attributed to the early Middle Jurassic Epoch, possibly the Aalenian-Bajocian. The climate of the Ordos Basin during the Middle Jurassic was warm and humid with seasonal temperature and precipitation fluctuations. The result tends to support the palaeophytogeographic/palaeoclimatic setting of the Ordos Basin in the North Floristic Province, or the North Chinese Province in the warm temperate zone during the Middle Jurassic.