新疆石油地质 ›› 2025, Vol. 46 ›› Issue (5): 637-646.doi: 10.7657/XJPG20250515

• 国外油气地质 • 上一篇    

不同类型火成岩基底古风化特征评估

梁飞(), 牛君(), 何进   

  1. 中国石油大学(北京)克拉玛依校区 石油学院,新疆 克拉玛依 834000
  • 收稿日期:2025-03-11 修回日期:2025-05-17 出版日期:2025-10-01 发布日期:2025-09-30
  • 通讯作者: 牛君(1986-),女,新疆克拉玛依人,副教授,博士,沉积地质,(Tel)15809903280(Email)2017592007@cupk.edu.cn
  • 作者简介:梁飞(1992-),男,安徽亳州人,讲师,博士,石油地质,(Tel)18611286346(Email)liang@cupk.edu.cn
  • 基金资助:
    中国石油大学(北京)克拉玛依校区科研启动基金(XQZX20240017);新疆维吾尔自治区自然科学基金—地州科学基金(2022D01F59);自治区高校基本科研业务费(XJEDU2024P105);克拉玛依市创新环境建设计划(创新人才)(2024hjcxrc0046)

Evaluation of Paleoweathering Characteristics of Igneous Rock Basements

LIANG Fei(), NIU Jun(), HE Jin   

  1. School of Petroleum, Karamay Campus, China University of Petroleum (Beijing), Karamay, Xinjiang 834000, China
  • Received:2025-03-11 Revised:2025-05-17 Online:2025-10-01 Published:2025-09-30

摘要:

古风化壳对于了解岩石圈与大气圈的相互作用,以及埋藏成岩过程中风化剖面内的岩-水反应具有重要意义。对不同类型火成岩基底,包括辉长闪长岩(GA1基底)、玄武安山岩(GA1喷出岩层段)、石英闪长岩(TB8基底)和花岗岩(BK2/05基底)开展了系统的岩石学、矿物学和地球化学特征分析。利用迁移程度对K、Ca、Na等易迁移元素偏移量进行量化,将结果与全岩X射线衍射矿物定量分析结果以及岩石学特征进行交叉对比,明确研究区古风化壳埋藏成岩作用特征。其次,结合矿物与元素含量,对Ca进行定量校正,在此基础之上校正K含量,校正之后的结果在A-C-K三角图中显示出良好的风化趋势,表明校正方法合理。将校正之后的参数利用化学蚀变指数对化学风化程度进行量化,结合原岩特征及古气候特征对原始风化产物进行校正,得出古风化剖面原始的风化特征。最终,利用风化指数归一化方法校正之后,各个风化剖面风化特征与早—中二叠世气候变化特征显示出良好的对应关系。

关键词: 德国西南部, 火成岩, 化学风化, 古风化特征, 成岩流体, 评估方法

Abstract:

Paleoweathering crusts are of significant importance for understanding the interactions between the lithosphere and the atmosphere, as well as the rock-water reactions within weathering profiles during burial diagenesis process. This study systematically analyzed petrological, mineralogical, and geochemical characteristics of various igneous rock basements, including gabbro-diorite (GA1 basement), basaltic andesite (GA1 effusive rock interval), quartz diorite (TB8 basement), and granite (BK2/05 basement). The mobility offsets of easily migrating elements such as K, Ca, and Na were quantified using the degree of migration, and the results were cross-referenced with mineral quantitative analysis data from whole-rock X-ray diffraction (XRD) and the petrological features to clarify the burial diagenetic characteristics of the paleoweathering crust in the study area. Subsequently, based on the mineral and element contents, a quantitative correction was applied to Ca content, followed by a correction for K content. The corrected results displayed a well-defined weathering trend in the A-C-K triangular chart, validating the methodology for correction. Using the corrected parameters, the chemical index of alteration (CIA) was employed to quantify the degree of chemical weathering. Additionally, corrections for the original weathering products were performed by integrating protolith characteristics and paleoclimate features, revealing the original weathering characteristics of the paleoweathering profile. Finally, after normalization using weathering indices, the corrected weathering characteristics of each profile exhibited strong correlations with the climatic evolution trends during the Early to Middle Permian.

Key words: southwestern Germany, igneous rock, chemical weathering, paleoweathering characteristic, diagenetic fluid, evaluation method

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