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现代地质 ›› 2025, Vol. 39 ›› Issue (03): 774-786.DOI: 10.19657/j.geoscience.1000-8527.2024.140

• 机器学习与矿物学应用 • 上一篇    下一篇

白云母/黑云母Ti地质温度计的适用性:桂东北资源韧性剪切带例析

刘锟1,2(), 李赛赛1,2,*(), 辛良伟1,2, 石春燕3, 耿杰利1   

  1. 1.桂林理工大学有色金属矿产勘查与资源高效利用省部共建协同创新中心,广西 桂林 541004
    2.桂林理工大学地球科学学院,广西 桂林 541004
    3.桂林理工大学旅游与风景园林学院,广西 桂林 541004
  • 出版日期:2025-06-10 发布日期:2025-07-03
  • 通信作者: *李赛赛,男,博士,教授,1983年出生,主要从事构造地质学研究工作。Email:lanqi178@glut.edu.cn
  • 作者简介:刘 锟,男,硕士研究生,1995年出生,主要从事构造地质学研究工作。Email:1037961211@qq.com
  • 基金资助:
    广西自然科学基金项目(2020JJA150030);国家自然科学基金项目(42262026)

Applicability of Muscovite/Biotite Ti geothermometers: A Case Study of Ziyuan Ductile Shear Zone in Northeast Guangxi

LIU Kun1,2(), LI Saisai1,2,*(), XIN Liangwei1,2, SHI Chunyan3, GENG Jieli1   

  1. 1. Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of Resources By the Province and Ministry, Guilin University of Technology, Guilin, Guangxi 541004, China
    2. College of Earth Sciences, Guilin University of Technology, Guilin, Guangxi 541004, China
    3. College of Tourism and Landscape Architecture, Guilin University of Technology, Guilin, Guangxi 541004, China
  • Published:2025-06-10 Online:2025-07-03

摘要:

自然界中不同的应力体制、应变速率都可能影响岩石脆-韧性变形的转换温度,而韧性剪切带中糜棱岩的变形变质温度估算对热年代学结果的解释具有重要制约。为了讨论地质温度计(白云母/黑云母Ti地质温度计)在伸展韧性剪切带中的适用性,本文利用糜棱岩的矿物动态重结晶以及EBSD石英<c>轴组构等塑性变形特征,估算出桂东北资源韧性剪切带的变形变质温度在400~550 ℃之间。结合电子探针分析技术,对韧性剪切过程中由于动态重结晶作用新形成的细粒白云母、黑云母进行化学成分分析,利用白云母/黑云母Ti温度计估算出该韧性剪切带中糜棱岩的变形变质温度分别为409~528 ℃和458~605 ℃。通过对比分析,利用地质温度计获得的温度与利用塑性变形特征估算出的温度在误差允许范围内基本一致,为白云母/黑云母Ti温度计在伸展韧性剪切带中的应用提供了依据。

关键词: 桂东北, 韧性剪切带, 糜棱岩, 地质温度计, 变形变质温度

Abstract:

Different stress regimes and strain rates in nature can influence the transition temperature of rocks from brittleness to ductility, estimating the deformation and metamorphism temperatures of mylonite in ductile shear zones is crucial for interpreting thermochronological results. To assess the applicability of geothermometers(biotite/muscovite Ti geothermometers) in ductile shear zones, our study employed mineral dynamic recrystallization of mylonite and plastic deformation features, such as EBSD quartz <c>-axis fabrics, to estimate the deformation and metamorphism temperatures of Ziyuan ductile shear zones in Northeastern Guangxi, ranging from 400 to 550 ℃. Through the utilization of electron probe analysis techniques, chemical composition analyses were conducted on newly formed fine-grained biotite and muscovite resulting from dynamic recrystallization during ductile shearing. By employing biotite/muscovite Ti thermometers, the metamorphic deformation temperature of mylonite in the Ziyuan ductile shear zone were estimated to be between 409-528 ℃ and 458-605 ℃, respectively. Through comparative analysis, the temperatures obtained using geothermometers were essentially consistent within the allowable error range with those estimated using plastic deformation features, providing a basis for the application of biotite/muscovite Ti thermometers in extensional ductile shear zones.

Key words: Northeast Guangxi, ductile shear zone, mylonite, geothermometer, metamorphic-deformation temperature

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