1. Oil & Gas Survey, China Geological Survey, Beijing 100083, China;
2. The Key Laboratory of Unconventional Petroleum Geology, China Geological Survey, Beijing 100083, China;
3. College of Earth Sciences, Jilin University, Changchun 130061, China;
4. Jilin Geological Exploration Institute, China Chemical Geology and Mine Bureau, Changchun 130033, China;
5. Oil Sands Geological Survey and Technology Research and Development Laboratory, Oil & Gas Survey, CGS and China Chemical Geology and Mine Bureau, Changchun 130033, China;
6. Gems & Jewelry Trade Association of China, Beijing 100013, China

Based on the soil sample collection and testing, the geochemical characteristics, such as hydrocar-bons, altered carbonate and thermal released mercury were analyzed, and the abnormal values were counted and the lower limit of the anomalies was obtained. From the comprehensive geochemical anomalies, a set of two-peak a-nomaly combination is identified, which is associated with heavy hydrocarbons, altered carbonate and thermal re-leased mercury. In accordance with that characteristic of the anomaly, the target area of the oil sand exploration is delineated. Drilling data confirm that the core is oil-rich or oil-immersed in Yaojia Formation of Cretaceous, and the highest oil content is 12.86%, the average oil content is 5.40%, the maximum net thickness of oil sand is 12.40 m. The high correlation between the drilling verification and the geochemical anomaly proves that the method is effective in oil sand prospecting in Xiaotaipingshan area in the western slope of Songliao Basin. Meanwhile, it provides a reference for surface oil and gas geochemical exploration of similar oil sand.