Late Cretaceous Activity Record of the Guangsan Fault—Insights from Zircon U-Pb and Apatite Fission-Track Thermochronology
Late Cretaceous Activity Record of the Guangsan Fault—Insights from Zircon U-Pb and Apatite Fission-Track Thermochronology
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DOI：
10.3390/min12091163
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发表时间：
2022-09
期刊：
影响因子：
2.5
通讯作者：
Ruxin Ding;Weihao Chen;C. Soares;Weisheng Hou;Zilong Li;Yang Li;Rongli Huang;Heping Zou
中科院分区：
文献类型：
--
作者：
Ruxin Ding;Weihao Chen;C. Soares;Weisheng Hou;Zilong Li;Yang Li;Rongli Huang;Heping Zou
断层活动的时间是地质学家关心的问题。本研究利用断层角砾岩的锆石U-Pb和磷灰石裂变径迹测年来确定断层作用时间的上限和下限。以华南广三断裂带为例，对围岩和断层角砾岩进行了锆石U-Pb和磷灰石裂变径迹热年代学研究。围岩和断层角砾岩的锆石U-Pb年代分别为74.9~91.8 Ma和73.9~93.5 Ma，表明角砾岩形成于73.9 Ma之后。他们还证明了 71.6 ± 7.3 Ma 和 85.9 ± 8.2–65.5 ± 6.5 Ma 裂变径迹日期，这意味着断层角砾岩样本可能在约 70 Ma 之前形成。它们的热历史高度一致：均在70-65 Ma期间表现出快速冷却，在65-0 Ma期间表现出缓慢冷却，这意味着断层可能在70-65 Ma期间仍然活跃，导致快速折返。
The timing of fault activity is a concern for geologists. This study used zircon U-Pb and apatite fission-track dating of fault breccia to determine the upper and lower limits for the time of faulting. The Guangsan fault in South China was taken as an example, and zircon U-Pb and apatite fission-track thermochronology were applied to the surrounding rock and fault breccia. The surrounding rock and fault breccia demonstrated 74.9–91.8 Ma and 73.9–93.5 Ma zircon U-Pb dates, respectively, indicating that the breccia formed after 73.9 Ma. They also demonstrated 71.6 ± 7.3 Ma and 85.9 ± 8.2–65.5 ± 6.5 Ma fission-track dates, implying that the fault breccia samples likely formed before ~70 Ma. Their thermal histories were highly consistent: both showed rapid cooling during 70–65 Ma and slow cooling during 65–0 Ma, implying that the fault was likely still active during 70–65 Ma, resulting in the rapid exhumation.