Fig. 1
Location map of drilled wells in the Chengkou area. a Location of the study area. Note that the map of China is referring the standard map available on the official website of the Ministry of Natural Resources of China (http://bzdt.ch.mnr.gov.cn/); b Locations of drilled wells and the stratigraphic section (Lijiagou section). Note that the names of drilled wells on the map are changed due to confidentiality considerations