Mesozoic marine shale oil was found in the Qiangtang Basin by a large number of hydrocarbon geological surveys and shallow drilling sampling. Based on systematic observation and experimental analysis of outcrop and core samples, the deposition and development conditions and characteristics of marine shale are revealed, the geochemical and reservoir characteristics of marine shale are evaluated, and the layers of marine shale oil in the Mesozoic are determined. The following geological understandings are obtained. First, there are two sets of marine organic-rich shales, the Lower Jurassic Quse Formation and the Upper Triassic Bagong Formation, in the Qiangtang Basin. They are mainly composed of laminated shale with massive mudstone. The laminated organic-rich shale of the Quse Formation is located in the lower part of the stratum, with a thickness of 50–75 m, and mainly distributed in southern Qiangtang Basin and the central-west of northern Qiangtang Basin. The laminated organic-rich shale of the Bagong Formation is located in the middle of the stratum, with a thickness of 250–350 m, and distributed in both northern and southern Qiangtang Basin. Second, the two sets of laminated organic-rich shales develop foliation, and various types of micropores and microfractures. The average content of brittle minerals is 70%, implying a high fracturability. The average porosity is 5.89%, indicating good reservoir physical properties to the level of moderate–good shale oil reservoirs. Third, the organic-rich shale of the Quse Formation contains organic matters of types II₁ and II₂, with the average TOC of 8.34%, the average content of chloroform bitumen ‘A’ of 0.66%, the average residual hydrocarbon generation potential (S₁+S₂) of 29.93 mg/g, and the R_o value of 0.9%–1.3%, meeting the standard of high-quality source rock. The organic-rich shale of the Bagong Formation contains mixed organic matters, with the TOC of 0.65%–3.10% and the R_o value of 1.17%–1.59%, meeting the standard of moderate source rock. Fourth, four shallow wells (depth of 50–250 m) with oil shows have been found in the organic shales at 50–90 m in the lower part of the Bagong Formation and 30–75 m in the middle part of the Quse Formation. The crude oil contains a high content of saturated hydrocarbon. Analysis and testing of outcrop and shallow well samples confirm the presence of marine shale oil in the Bagong Formation and the Quse Formation. Good shale oil intervals in the Bagong Formation are observed in layers 18–20 in the lower part of the section, where the shales with (S₀+S₁) higher than 1 mg/g are 206.7 m thick, with the maximum and average (S₀+S₁) of 1.92 mg/g and 1.81 mg/g, respectively. Good shale oil intervals in the Quse Formation are found in layers 4–8 in the lower part of the section, where the shales with (S₀+S₁) higher than 1 mg/g are 58.8 m thick, with the maximum and average (S₀+S₁) of 6.46 mg/g and 2.23 mg/g, respectively.

通过大量油气地质调查和浅层钻井取样，在羌塘盆地发现了中生界海相页岩油。通过对露头和岩心样品的系统观测和实验分析，揭示海相页岩沉积发育条件和特征，评价海相页岩地球化学和储集层特征，确定中生代海相页岩油层位。获得以下地质认识。首先，羌塘盆地发育下侏罗统曲塞组和上三叠统巴公组两套海相富有机质页岩。主要由层状页岩夹块状泥岩组成。曲塞组层状富有机质页岩位于地层下部，厚度50～75 m，主要分布在羌塘盆地南部和羌塘盆地北部中西部。巴公组层状富有机质页岩位于地层中部，厚度250～350 m，分布于羌塘盆地北部和南部。其次，两套层状富有机质页岩发育叶理，以及各种类型的微孔和微裂缝。脆性矿物的平均含量为70%，具有较高的可碎性。平均孔隙度为5.89%，储层物性良好，达到中优质页岩油储层水平。三是曲塞组富有机质页岩含有II ₁和II ₂型有机质，平均TOC为8.34%，氯仿沥青'A'平均含量为0.66%，平均残余生烃潜力( S ₁ + S ₂）为29.93 mg/g，R _o值为0.9%～1.3%，满足优质烃源岩标准。八公组富有机质页岩含有混合有机质，TOC为0.65%～3.10%，R _o值为1.17%～1.59%，符合中度烃源岩标准。四是在八公组下部50~90 m、曲色组中部30~75 m有机页岩中发现4口浅井（深度50~250 m）有油显示。原油含有高含量的饱和烃。对露头和浅井样品的分析和测试证实了巴公组和曲色组中存在海相页岩油。剖面下部18～20层为八公组页岩油层段较好，其中（S ₀ + S ₁）大于1 mg/g的页岩厚度为206.7 m，最大和平均厚度为206.7 m。 ( S ₀ + S ₁）分别为1.92毫克/克和1.81毫克/克。曲塞组页岩油较好层段位于剖面下部4~8层，其中（S ₀ + S ₁）大于1 mg/g的页岩厚度为58.8 m，最大和平均厚度为58.8 m。 ( S ₀ + S ₁ )分别为6.46mg/g和2.23mg/g。