Constraining the denudation process in the eastern Sichuan Basin, China using low-temperature thermochronology and vitrinite reflectance data
Constraining the denudation process in the eastern Sichuan Basin, China using low-temperature thermochronology and vitrinite reflectance data
复制标题
利用低温热年代学和镜质体反射数据约束中国四川盆地东部的剥蚀过程
DOI：
10.1002/gj.3191
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发表时间：
2019
影响因子：
1.8
通讯作者：
Hu Shengbiao
中科院分区：
文献类型：
--
作者：
Zhu Chuanqing;Qiu Nansheng;Liu Yifeng;Xiao Yao;Hu Shengbiao
根据低温热年代学和镜质组反射率资料重建了样品的温度历史和钻孔的最大古地温剖面，为川东地区的抬升剥蚀的时间尺度和数量提供了界限。热史研究表明，川东地区的隆升和冷却作用始于晚白垩世(约100-80 Ma)。从晚白垩世到现在，该地区经历了一个持续的冷却过程，地温梯度从32-36℃/公里下降到20-23℃/公里。川东北普光地区剥蚀量约2.3千米，川东南剥蚀量约1.9千米，野外样品揭示的川东褶皱带剥蚀量为2.3千米±0.30千米-2.6千米±0.30千米。川东北地区经历了持续降温，但波动不明显，而冲断带和川盆地东南部经历了2-4个阶段，降温速度不同。这可能表明川东褶皱带自晚白垩世以来经历了以幕式隆升和变形为特征的复杂构造演化，而四川盆地东北部则发生了不同的、温和的变形。
The temperature history of samples and maximum palaeogeothermal profiles of boreholes were reconstructed based on low‐temperature thermochronology and vitrinite reflectance data, and the results provide limits for the timescale and amount of uplift–denudation of the eastern Sichuan Basin. The thermal history showed that the uplifting and cooling of eastern Sichuan Basin began around the Late Cretaceous (approximately 100–80 Ma). The region had experienced a continuous cooling process from the Late Cretaceous until the present, with the geothermal gradient decreasing from 32–36 °C/km to 20–23 °C/km. The amount of denudation at the Puguang region in north‐eastern Sichuan was approximately 2.3 km, whereas that at south‐eastern Sichuan was 1.9 km, and the erosion thickness in the eastern Sichuan fold belt that was revealed via the field samples is 2.3 ± 0.3–2.6 ± 0.3 km. The north‐eastern Sichuan experienced sustained cooling with inconspicuous fluctuations, whereas the thrust belt and the south‐eastern Sichuan Basin presented 2–4 stages with different cooling rates. It may indicate that the eastern Sichuan fold belt experienced a complex structural evolution, characterized by episodic upliftings and deformations since Late Cretaceous, while a different and gentle deformation took place in the northeastern Sichuan Basin.