## 3 Data and Methods  
In this work, all of the analyzed source rock samples from the J\({}_{3}\)tm formation were collected from Hongqi Depression in the Hailar Basin (Figure 1a). The samples from three wells (H6, H7, and H8) with depths from 2200 m to 3565 m consist of 87 mudstone samples and were used for Rock-Eval pyrolysis and the determination of total organic carbon content (%), chloroform bitumen \"A\" (%), kerogen carbon isotope \"\(8^{13}\)C\({}_{\text{PDB}}\)\", total reduced sulfur, and vitrinite reflectance (Ro%). All mudstone samples were pulverized to 100 mesh in preparation for those experiments. Rock-Eval/TOC was conducted at the State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University and provided the measurements of TOC (wt%), Tmax, S\({}_{1}\) and S\({}_{2}\). The temperature was set to 300 \({}^{\circ}\)C for 3 min and then heated up to 600 \({}^{\circ}\)C at a rate of 25 \({}^{\circ}\)C/min. Tmax represents the temperature that corresponds to the maximum generation rate of hydrocarbons from kerogen cracking. S\({}_{1}\) represents any free hydrocarbons. S\({}_{2}\) represents the amount of hydrocarbons expelled from kerogen cracking. Some parameters were then generated from the Rock-Eval pyrolysis techniques: Hydrogen index [HI = (S\({}_{2}\)/TOC) \(\times\) 100, mgHC/g TOC] is the normalized S\({}_{2}\) value (S\({}_{2}\)/TOC), indicating the potential of kerogen in a rock to generate petroleum [33; 34]. The TRS of source rocks was measured using a LECO CS-230 analyzer (LECO Corporation, St. Joseph, MI, USA). The results are listed in the Table 1.  
Kerogens separated from mudstones were used for observations and testing with a DLAPLAN biological microscope (Leica Microsystems GmbH, Wetzlar, Germany). They were also used for thin sections in preparation for vitrinite reflectance (Ro%) determinations and were placed under reflected light in a ZEISS Axio Microscope (Carl Zeiss AG, Oberkochen, Germany). The vitrinite reflectance measurement system used a TIDAS PMT IV photometer (J&M Analytik AG, Essingen, Germany) and MSP200 testing software (Version 3.47). The detailed methods, experimental conditions, and algorithm for selecting the appropriate values were optimized. The results are shown in Table 1. To more accurately assess organic matter types and depositional conditions, kerogen carbon isotope (\(8^{13}\)C\({}_{\text{PDB}}\)) analyses were conducted with an MAT-251 Stable Isotope Mass Spectrometer (Finnigan MAT, Waltham, MA, USA). The chloroform bitumen \"A\" was determined using the Soxhlet extraction method. The rock samples were crushed to 0.09 mm powder, extracted with chloroform continuously for 72 h, and then dried to calculate the content of soluble organic matter in the unit rock. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Well** & **Lithology** & **Depth** & **TOC** & **“A”** & **S\({}_{1}\)** & **S\({}_{2}\)** & **S\({}_{1}\) + S\({}_{2}\)** & **HI** & **OI** & **Tmax** & **Ro** & **\(\delta^{13}\)C\({}_{\text{PDB}}\)** \\  & **(m)** & **(\%)** & **(\%)** & **(mg/g)** & **(mg/g)** & **(mg/g)** & **(mg/g)** & **(mg/g)** & **(\%/g)** & **(\%)** & **(\%)** & **(\%)** \\ \hline H6 & Mudstone & 2580 & 0.27 & 0.083 & 0.84 & 0.31 & 1.15 & 115 & 36.95 & 440 & 0.80 & / \\ \hline H6 & Mudstone & 2640 & 0.32 & 0.051 & 0.04 & 0.28 & 0.32 & 88 & 9.40 & 443 & / & / \\ \hline H6 & Mudstone & 2740 & 1.49 & 0.419 & 0.82 & 4.81 & 5.63 & 323 & 31.58 & 447 & 0.90 & \(-\)26.142 \\ \hline H6 & Mudstone & 2742 & 1.89 & / & 1.86 & 6.91 & 8.77 & 365 & 39.13 & 447 & / & / \\ \hline H6 & Mudstone & 2744 & 2.01 & / & 1.38 & 7.28 & 8.66 & 363 & 35.89 & 443 & / & / \\ \hline H6 & Mudstone & 2746 & 1.24 & 0.385 & 0.36 & 4.11 & 4.47 & 332 & 29.93 & 437 & 0.90 & \(-\)25.447 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Geochemical data of the Jurassic Tamulangou Formation source rocks in the Hongqi Depression. Additionally, gas chromatography (GC) data were also collected from the J3 tm formation from three wells in the Hongqi Depression.