| 羌塘盆地中部侏罗系埋藏史和生烃史 |
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| 引用本文： | 吴珍汉,季长军,赵珍,陈程.羌塘盆地中部侏罗系埋藏史和生烃史[J].地质学报,2020,94(10):2823-2833. |
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| 作者姓名： | 吴珍汉 季长军 赵珍 陈程 |
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| 作者单位： | 1) 中国地质科学院，北京，100037;2) 中国地质科学院地质力学研究所，北京，100081 |
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| 基金项目： | 本文为中国地质调查局“羌塘盆地油气地质构造保存条件研究”（编号1212011221111）和“中国大地构造演化和国际亚洲大地构造图编制”（编号DD20190367）项目资助成果。 |
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| 摘 要： | 综合野外观测、地震反射、钻探标定及镜质体反射率、古地温等相关资料，分析羌塘盆地中部不同地区侏罗系海相沉积地层的埋藏史、热史和生烃史。结果显示，羌塘盆地万安湖地区、半岛湖背斜、阿木错地区、比洛错古油藏早侏罗世海相泥页岩在沉积之后，中、晚侏罗世埋深快速增加，镜质体反射率Ro随之增大，晚侏罗世早中期下侏罗统泥页岩镜质体反射率 R o增至05%，主力烃源岩进入生烃门限开始生烃；早白垩世早期145~143Ma侏罗系海相地层埋深、古地温和 R o达到极大值，比洛错油页岩开始早期生油，阿木错主力烃源岩进入第一期生烃高峰。早白垩世构造隆升及风化剥蚀导致侏罗系海相地层向上折返，埋深减小，晚白垩世和古近纪早期前陆凹陷和红层沉积导致侏罗系海相地层埋深增加。比洛错古油藏Toarcian期油页岩晚白垩世末期古地温和 R o达到最大值，~66Ma形成生烃高峰；阿木错地区Toarcian期含油泥页岩始新世中期~43Ma埋深达到最大值，形成第二期生烃高峰。
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| 关 键 词： | 侏罗系 海相烃源岩 埋藏史 生烃史 羌塘盆地 |
| 收稿时间： | 2020/5/11 0:00:00 |
| 修稿时间： | 2020/5/11 0:00:00 |
Buried depth evolution and hydrocarbon generation history of the Jurassic System in central Qiangtang Basin |
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| WU Zhenhan,JI Changjun,ZHAO Zhen,CHEN Chen.Buried depth evolution and hydrocarbon generation history of the Jurassic System in central Qiangtang Basin[J].Acta Geologica Sinica,2020,94(10):2823-2833. |
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| Authors: | WU Zhenhan JI Changjun ZHAO Zhen CHEN Chen |
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| Institution: | 1) Chinese Academy of Geological Sciences, Beijing, 100037;2) Institute of Geomechanics, CAGS, Beijing, 100037 |
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| Abstract: | Buried depth change, thermal evolution and hydrocarbon generation history of the Jurassic marine strata in typical areas of the Qiangtang basin are analyzed synthetically according to field geological survey, seismic reflection profile, drilling records, vitrinite reflectance and paleo- temperature. Buried depth of the Lower Jurassic marine mudstone and shale increased from the Middle to Late Jurassic in the Wananhu area, Bandaohu anticline, Amuco area and Bilogco paleo- oil reservoir. Vitrinite reflectance R o of the Lower Jurassic mud shale increased to 0.5%, and the marine source rock began hydrocarbon generation in the Late Jurassic. The buried depth, paleo- temperature and R o increased to maximum in 145~143Ma, Early Cretaceous, which resulted in minor oil generation of the Toarcian oil shale in the Bilogco area and the first peak of hydrocarbon generation of Toarcian mud shale in the Amuco area. Buried depth of the Jurassic marine strata decreased since the Early Cretaceous due to uplift and erosion, and increased evidently due to crust depression and redbeds formation in the Late Cretaceous and Early Paleogene. The paleo- temperature and R o of Toarcian oil shale increased to maximum at ~66Ma, which formed peak of hydrocarbon generation in the Bilogco paleo- oil reservoir. Buried depth of the Toarcian mud shale reached to maximum at ~43Ma, which formed the second peak of hydrocarbon generation in the Amuco area. |
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| Keywords: | Jurassic system marine source rock buried depth change hydrocarbon generation history Qiangtang Basin |
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