曹厚臻^1,2,3,,
何丽娟^1,2,3,,,
张林友^1,2,3
1. 中国科学院地质与地球物理研究所岩石圈演化国家重点实验室, 北京 100029
2. 中国科学院地球科学研究院, 北京 100029
3. 中国科学院大学, 北京 100049

基金项目: 国家重点研发计划(2016YFC0601005), 国家自然科学基金(41574075)资助


详细信息

作者简介: 曹厚臻, 男, 1994年生, 硕士研究生, 构造地质学专业, 从事地热学数值模拟研究.E-mail:caohouzhen@mail.iggcas.ac.cn

通讯作者: 何丽娟, 女, 1968年生, 研究员, 博士生导师, 从事岩石圈构造-热演化模拟研究.E-mail:ljhe@mail.iggcas.ac.cn

中图分类号: P314

收稿日期:2018-04-18
修回日期:2018-10-20
上线日期:2019-01-05

Inversion of background thermal history since the formation of the Tarim Craton

CAO HouZhen^1,2,3,,
HE LiJuan^1,2,3,,,
ZHANG LinYou^1,2,3
1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2. Institute of Earth Science, Chinese Academy of Sciences, Beijing 100029, China
3. University of Chinese Academy of Sciences, Beijing 100049, China


More Information

Corresponding author: HE LiJuan,E-mail:ljhe@mail.iggcas.ac.cn

MSC: P314

--> Received Date: 18 April 2018
Revised Date: 20 October 2018
Available Online: 05 January 2019


摘要
摘要:塔里木盆地是一个典型大型叠合盆地，发育在太古代-早中元古代的结晶基底之上，具有稳定克拉通性质.现今地表热流为43 mW·m^-2，平均地温梯度为21℃·km^-1，莫霍面温度为550℃，较低的热流背景值指示塔里木盆地经历了一个长期冷却加厚的过程.然而对于这样一个长期冷却过程，之前的研究都只停留在显生宙阶段，并未获得塔里木显生宙以前的热史.本文以塔里木地区已有的地热数据作为约束，依据地幔动力学模型设置底部边界条件，利用正演拟合的方法，反演出塔里木的背景热史，填补了该区域古生代以前热史研究的空白.结果表明，塔里木克拉通自形成以来背景热流不断降低（由85 mW·m^-2降至43 mW·m^-2），岩石圈持续加厚（由130 km加厚到190 km），在长时间尺度下，塔里木克拉通总体的热演化模式为长期冷却加厚，这与世界上其他典型克拉通的热演化规律类似.显生宙以来受到短期局部的构造-热事件影响，塔里木克拉通在长期冷却的趋势下叠加了约20~40 mW·m^-2的热扰动.
关键词: 塔里木克拉通/
热演化/
长期冷却/
岩石圈厚度/
构造-热事件

Abstract:The Tarim basin is a typical large-scale superimposed structure which developed on a Archean-Early Proterozoic crystalline basement, with stable craton properties. Its present-day surface heat flux is only 43 mW·m^-2, with average geothermal gradient 21℃·km^-1 and Moho temperature 550℃. The low heat flow background value indicates that this basin experienced a process of secular cooling and thickening. However, for such a secular cooling process, previous studies only concentrated on Phanerozoic stage and did not cover the entire thermal history of Tarim. In this paper, we use the thermal data of the Tarim area as a constraint, and set up the bottom boundary conditions according to different mantle dynamic models. Then, the background thermal history of Tarim is reconstructed by forward modeling, which fills the gap in the study of thermal history before the Palaeozoic in this region. The results show that the background heat flow of Tarim was decreasing (reduced from 85 mW·m^-2 to 43 mW·m^-2) and the lithosphere was thickening (increased from 130 km to 190 km) continuously since the basin's formation. On a long time scale, the thermal evolution model of the Tarim craton is secular cooling and thickening, which is similar to that of other typical cratons in the world. While, under the influence of short-term local tectono-thermal events, the thermal history of the Tarim craton was superposed by about 20~40 mW·m^-2 thermal disturbance on the trend of secular cooling.
Key words:Tarim craton/
Thermal evolution/
Secular cooling/
Lithosphere thickness/
Tectono-thermal event



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