地学前缘 ›› 2025, Vol. 32 ›› Issue (4): 291-302.DOI: 10.13745/j.esf.sf.2025.4.67

• 人工智能驱动地学知识发现 • 上一篇    下一篇

基于机器学习与垂向分层建模联合驱动的华北克拉通地温梯度空间分布预测

李金明1(), 张杨1, 成秋明1,2,*()   

  1. 1.中山大学 地球科学与工程学院, 广东 珠海 519000
    2.中国地质大学(北京) 地质过程与成矿预测全国重点实验室, 北京 100083
  • 收稿日期:2025-04-25 修回日期:2025-05-27 出版日期:2025-07-25 发布日期:2025-08-04
  • 通信作者: *成秋明(1960—),男,教授,博士生导师,中国科学院院士,主要从事数学地球科学、矿产普查与勘探领域的研究。E-mail: qiuming.cheng@iugs.org
  • 作者简介:李金明(1998—),男,硕士研究生,主要从事数学地球科学领域的研究。E-mail: lijm227@mail2.sysu.edu.cn
  • 基金资助:
    国家自然科学基金项目(42050103);国家自然科学基金项目(42430111);广东省“珠江人才计划”引进创新创业团队项目:大数据-数学地球科学与极端地质事件团队(2021ZT09H399)

Spatial distribution prediction of geothermal gradient in North China Craton driven by the combination of machine learning and stratification modeling

LI Jinming1(), ZHENG Yang1, CHENG Qiuming1,2,*()   

  1. 1. School of Earth Sciences and Engineering, Sun Yat-Sen University, Zhuhai 519000, China
    2. State Key Laboratory of Geological Processes and Mineralization Prediction, China University of Geosciences (Beijing), Beijing 100083, China
  • Received:2025-04-25 Revised:2025-05-27 Online:2025-07-25 Published:2025-08-04

摘要:

地温梯度作为表征岩石圈热状态的关键参数,其空间分布研究对于理解克拉通热结构演化机制和指导地热资源勘探具有重要意义。传统华北克拉通地温梯度研究多限于一维平面分布特征,未能充分揭示其垂向分异规律,导致预测模型精度受限。本研究创新性地构建了华北克拉通地温梯度深度分层预测模型,系统地阐明其深度依赖模式和热构造控制因素。基于全球热流数据库及前人研究成果,本研究整合了573个具有实测深度信息的地温梯度数据点,将其划分为6个深度段:<500 m,500~1 000 m,1 000~2 000 m,2 000~3 000 m,3 000~4 000 m,>4 000 m。选取居里面深度、大地热流值等13项地质-地球物理特征参数用来训练不同深度段的机器学习回归模型。研究显示:(1)模型预测性能具有显著深度依赖性,中浅部(0~3 000 m)R2>0.45,而深部因样本量减少精度下降;(2)特征重要性分析表明居里面深度与大地热流值对深部预测贡献显著(权重>40%),而磁异常和地质年代等影响较弱(<10%);(3)地温梯度三维分布呈现规律性垂向变化,即浅层高值区(>35 ℃/km)沿活动断裂带分布,中深层(500~3 000 m)高值带自西向东迁移,与太平洋板块俯冲引起的地壳减薄区具有空间耦合性。本研究首次尝试了华北克拉通地温梯度的三维建模,其成果不仅为区域地热资源评估提供了数据支撑,更为理解克拉通破坏过程中的热-构造耦合机制提供了新的观测约束。提出的深度分层建模方法为类似构造单元的热状态研究提供了范式参考。

关键词: 华北克拉通, 地热梯度, 机器学习, 地质与地球物理特征, 分层建模

Abstract:

As a key parameter characterizing the lithospheric thermal state, the spatial distribution of the geothermal gradient is crucial for understanding cratonic thermal evolution and guiding geothermal exploration. Previous studies on the North China Craton (NCC) were largely limited to one-dimensional analyses, failing to resolve vertical variations and limiting model accuracy. This study innovatively develops a depth-stratified prediction model for the NCC geothermal gradient, systematically elucidating its depth-dependent patterns and thermo-tectonic controls. Integrating 573 geothermal gradient measurements with depth information from global databases and literature, data were partitioned into six depth intervals: <500 m, 500-1000 m, 1000-2000 m, 2000-3000 m, 3000-4000 m, and >4000 m. Thirteen geological/geophysical predictors (e.g., Moho depth, geothermal heat flow) were used to train machine learning regression models for each interval. Key results show: (1) Model performance (R2) is depth-dependent: exceeding 0.45 in middle and shallower intervals (<3000 m), but declining significantly at greater depths due to sparse data; (2) Feature importance analysis reveals Moho depth and heat flow dominate deep predictions (weight>40%), while magnetic anomalies and geological age exert minor influence (<10%); (3) The 3D geothermal structure shows systematic depth variations: uppermost high-value zones (>35 ℃/km) align with active fault systems, while mid-deep high-value zones (500-3000 m) migrate eastward, correlating spatially with crustal thinning zones associated with Pacific Plate subduction. This work presents the first 3D geothermal gradient model of the NCC. Results provide critical data for regional geothermal assessment and new constraints on thermo-tectonic coupling during craton destruction. The depth-stratified framework offers a methodological paradigm for thermal studies of analogous tectonic units.

Key words: North China Craton, geothermal gradient, machine learning, geological and geophysical features, stratification modeling

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