北京大学学报（自然科学版） ›› 2026, Vol. 62 ›› Issue (5): 1046-1054.DOI: 10.13209/j.0479-8023.2026.096

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塔北地区西部上寒武统硅质沉积成因研究

石磊1,4,5,*, 徐浩然2,*, 王晓雪1, 王平1,4,5, 朱必清2, 张良1, 何衍鑫3, 关平2,†   

  1. 1. 中国石油塔里木油田勘探开发研究院, 库尔勒 841000 2. 造山带与地壳演化教育部重点实验室, 北京大学地球与空间科学学院, 北京 100871 3. 江西理工大学矿业工程学院, 赣州 341000 4. 中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心, 库尔勒 841000 5. 新疆维吾尔自治区超深层复杂油气藏勘探开发工程研究中心, 库尔勒 841000
  • 收稿日期:2025-07-30 修回日期:2025-11-10 出版日期:2026-09-20 发布日期:2026-09-20
  • 基金资助:
    国家自然科学基金(42141021)资助

Genesis of Siliceous Deposits in the Upper Cambrian Succession in the Western Margin of Northern Tarim Basin

SHI Lei1,4,5,*, XU Haoran2,*, WANG Xiaoxue1, WANG Ping1,4,5, ZHU Biqing2, ZHANG Liang1, HE Yanxin3, GUAN Ping2,†   

  1. 1. Research Institute of Petroleum Exploration and Development, PetroChina Tarim Oilfield Company, Korla 841000 2. The Key Laboratory of Orogenic Belts and Crustal Evolution (MOE), School of Earth and Space Sciences, Peking University, Beijing 100871 3. School of Mining Engineering, JiangXi University of Science and Technology, Ganzhou 341000 4. CNPC R&D Center for Ultra Deep Complex Reservoir Exploration and Development, Korla 841000 5. Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development, Xinjiang Uygur Autonomous Region, Korla 841000
  • Received:2025-07-30 Revised:2025-11-10 Online:2026-09-20 Published:2026-09-20

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摘要：

基于锗/硅比值(Ge/Si), 结合主量和微量元素含量等地球化学指标, 探讨塔北地区西部上寒武统下丘里塔格组白云岩中硅质沉积的成因。结果表明, 白云岩中SiO2含量为65.40%~99.49% (平均值>90%), Ge/Si值为0.12~2.74 μmol/mol (平均值为0.54 μmol/mol), 显著低于热液端元值(4~25 μmol/mol), 靠近马纳火成岩体的样品Ge/Si值升高; Ge/Si值与Al2O3含量无相关性, 但与 Fe2O3含量正相关。低Ge/Si值及低Al2O3含量指示硅质主体为残余海水沉淀, 后期受一定程度的热液流体改造作用, 形成脉状集合体。研究区西部样品中Al2O3含量普遍高于东部, 揭示自东向西水动力减弱, 导致细粒陆源碎屑在局限台地富集。研究结果可以为厘清研究区下丘里塔格组白云岩储层中硅质的来源和成岩演化提供关键的地球化学约束, 对深层油气勘探具有指导意义。

关键词: 塔北地区, 上寒武统, 下丘里塔格组, 硅质沉积, Ge/Si

Abstract:

The origin of siliceous material in dolostones of the Upper Cambrian Lower Qiulitage Formation in the western margin of Northern Tarim Basin was investigated using germanium/silicon (Ge/Si) ratios together with major- and trace-element geochemistry. The dolostones contain 65.40%–99.49% SiO2 (mean value > 90%) and yield Ge/Si ratios of 0.12–2.74 μmol/mol (mean value = 0.54 μmol/mol), far below typical hydrothermal end-member values of 4–25 μmol/mol; samples close to the Mana igneous body show elevated ratios. Ge/Si correlates positively with Fe2O3 but shows no relationship with Al2O3. Taken together, the low Ge/Si ratios and low Al2O3 contents indicate that the silica precipitates mainly from residual seawater and is subsequently overprinted, to a limited extent, by hydrothermal fluids that produced vein-hosted aggregates. Al2O3 contents increase systematically from east to west across the study area, pointing to a westward decrease in hydrodynamic energy that favours the accumulation of fine-grained terrigenous detritus on the restricted platform. These findings place important geochemical constraints on the silica provenance and diagenetic history of the Lower Qiulitage dolostone reservoirs and have implications for deep hydrocarbon exploration.

Key words: Northern Tarim Basin, Upper Cambrian, Xiaqiulitage Formation, dolostone, Ge/Si

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