Figure 1

(a) Structural map of the top of the basement in the central paleo-uplift zone and the distribution of well locations (modified from Du et al., 20,171); (b) basement stratigraphic column of the LT1 well; (c) basement stratigraphic column of the LT2 well (This figure was drawn by CorelDRAW Graphics Suite 2019, vision number: 21.3.0.755, url:https://www.corel.com/cn).