A series of micro-type fault-depressed basins of the Late Cenozoic are distributed in west Yunnan Province. Each of them is less than 250 km

2

.Among them

there are four basins with an area of more than 80km

2

sediment thickness greater than 1

000m. Now oil and gas have been discovered in theJinggu Basin. The Jinggu Basin

with an area of 83 km

2

is a dustpan-like fault-depressed basin formed upon the folded basement of Early Tertiary. It containscoal-series strata of continental sand-mudstone with a thickness of more than 2

400m

and is characterized by: (1) great thickness of sediments and sourcerock; (2) source rock is rich in organic matter (organic carbon is 1.145%

chloroform bitumen A is 0.12%

total hydrocarbon is 1307 ppm)

and hasreached lower matured stage (vitrinite reflectance R

o

is 0.61-0.69%); (3)dis-posal relationship of generating

reservoiring and covering combination is good.