Mechanism Analysis of Organic Matter Enrichment of Upper Ordovician-Lower Silurian Shale in the Upper Yangtze Area: Taking Jiaoye-1 Well in the Jiaoshiba Block as an Example

Table 1

U/Th ratios of the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation 1st member in the Jiaoye-1 well in the Upper Yangtze area. See Figure 1 for the well location.

Formation	Depth (m)	Proportion (%)
		Wufeng	2411~2415	15.15	66.67	18.18
Longmaxi	2406~2411	0.00	17.50	82.50
Longmaxi	2386~2406	28.75	60.00	11.25
Longmaxi	2326~2386	95.42	4.58	0.00