Depth(km) Lithology Values of δ13C(‰) alkane aromatic hydrocarbon non-hydrocarbon 3.963 Dark-gray salted mudstone -27.6 -25.5 -25.7 3.968 Dark-gray salted mudstone -27.3 -25.3 -25.6 3.971 Dark-gray salted mudstone -27.4 -25.3 -25.5 3.973 Dark-gray salted mudstone -27.4 -25.3 -25.6 4.024 Salted rock -25.0 -23.9 -24.5 4.295 Laminated mudstone -24.2 -22.8 -24.3 4.301 Laminated mudstone -21.0 -21.0 -22.6 4.498 Dark-gray gypsum-salted mudstone -22.4 -23.6 -23.6 4.499 Dark-gray gypsum-salted mudstone -25.2 -24.3 -25.3 4.500 Dark-gray gypsum-salted mudstone -22.1 -23.2 -24.2 4.501 Dark-gray gypsum-salted mudstone -23.9 -24.3 -25.6

Table 2: The characteristics of carbon isotope of the group composition of the organic matter in the middle part of Member-4 of Shahejie Formation from the Well Fs2 in the Dongying depression.