Wayao Fm

The naming section is located on the banks of the Changchang River 150 m northwest of a highway bridge east of a brick factory in the Changchang coal mining area, Qiongshan County, Hainan. Named by Chen Renming et al. in 1980.

Mainly grayish white or yellowish gray inequigranular grit, pebbly sandstone and fine conglomerate, the lower part of which is intercalated with caesious mudstone, brownish gray or purplish red muddy siltstone and brownish purple oily mudstone lenses, yielding plants and sporopollen. The formation is divided into two parts: Lower part is grayish white or gray sandstone, pebbly sandstone and sandy conglomerate, with caesious white mudstone; Upper part is alternating grayish white pebbly grit and sandy conglomerate and gray or grayish green medium-fine sandstone and siltstone, showing a binary structure. Sandstone contains appreciable amount of feldspar, which forms a sandy kaolin deposit after weathered; it is the controlling horizon of the Changchang sandy kaolin deposit. The thickness is ~276 m.

This formation contains plants and sporopollen. The sporopollen is represented by the Alnipollenites-Quercoidites-Liquidambarpollenites assemblage, assigned to the late Eocene age.

This formation belongs to fluvio-lacustrine deposits.