Meso-Cenozoic Tectonothermal History of Permian Strata, Southwestern Weibei Uplift: Insights from Thermochronology and Geothermometry
Meso-Cenozoic Tectonothermal History of Permian Strata, Southwestern Weibei Uplift: Insights from Thermochronology and Geothermometry
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渭北隆起西南部二叠纪地层中新生代构造热历史：来自热年代学和地温测量的见解
DOI：
10.1111/1755-6724.14367
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Wang Baojiang
中科院分区：
文献类型：
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作者：
Yu Qiang;Ren Zhanli;Li Rongxi;Tao Ni;Qi Kai;Jiang Cheng;Wang Baojiang
该研究对鄂尔多斯盆地渭北隆起西南部旗山地区二叠纪地层中新生代构造演化史进行了综合解释。磷灰石裂变径迹和磷灰石/锆石（U-Th）/He热年代学，沥青反射率，岩石的热导率，古温度恢复和盆地建模被用来恢复二叠纪地层的中新生代构造历史。三叠纪AFT数据的组合年龄为0.180 ±7 Ma，有一个年龄峰值，P（χ2）= 86%。两个二叠系砂岩的校正磷灰石（U-Th）/He年龄平均值为168±4 Ma，寒武系地层的锆石（U-Th）/He年龄为231±14 Ma。两套奥陶系泥岩的沥青反射率和最高古温度分别为1.81%、1.57%和1.210 °C、1.196 °C。二叠纪地层在三叠纪受部分地区侵入岩的影响经历了一次快速的沉降和升温后，在晚侏罗世达到最高古地温之后，经历了四个冷却-抬升阶段：（1）冷却阶段，（163 ~ 140 Ma），温度为132 ~ 153 °C，冷却速率为133 °C/Ma，剥蚀厚度为1900 m，抬升速率为182 m/Ma;（2）冷却阶段（3）（140 ~ 152 Ma），温度为153 ~ 147 °C，冷却速率小于0.1°C Ma，剥蚀厚度为300 m，抬升速率为300 m/Ma;（0.52 ~ 0.8Ma），温度为0.47 ~ 0.43 °C，剥蚀速率为0.011 m/Ma，剥蚀厚度为0.500 m;（3）（198 Ma至今）温度为143 °C ~ 120 °C，剥蚀速率为133 °C/Ma，剥蚀厚度为1650 m，抬升速率为181 m/Ma。祁山地区三叠纪构造演化历史受秦岭造山运动和渭北隆起相互作用的影响，祁山南部地区的隆升冷却时间最早。早始新世（1.52 Ma）和晚中新世（1.88 Ma）是鄂尔多斯盆地渭北隆起西南部旗山地区二叠纪地层隆升-冷却历史的两个关键时期，是隆升速率和温度速率迅速变化的两个重要转折点。
This study provides an integrated interpretation for the Mesozoic ‐ Cenozoic tectonothermal evolutionary history of the Permian strata in the Qishan area of the southwestern Weibei Uplift, Ordos Basin. Apatite fission‐track and apatite/zircon (U‐Th)/He thermochronometry, bitumen reflectance, thermal conductivity of rocks, paleotemperature recovery, and basin modeling were used to restore the Meso‐Cenozoic tectonothermal history of the Permian Strata. The Triassic AFT data have a pooled age of ∼180±7 Ma with one age peak and P(χ2)=86%. The average value of corrected apatite (U‐Th)/He age of two Permian sandstones is ∼168±4 Ma and a zircon (U‐Th)/He age from the Cambrian strata is ∼231±14 Ma. Bitumen reflectance and maximum paleotemperature of two Ordovician mudstones are 1.81%, 1.57% and ∼210°C, ∼196°C respectively. After undergoing a rapid subsidence and increasing temperature in Triassic influenced by intrusive rocks in some areas, the Permian strata experienced four cooling‐uplift stages after the time when the maximum paleotemperature reached in late Jurassic: (1) A cooling stage (∼163 Ma to ∼140 Ma) with temperatures ranging from ∼132°C to ∼53°C and a cooling rate of ∼3°C/Ma, an erosion thickness of ∼1900 m and an uplift rate of ∼82 m/Ma; (2) A cooling stage (∼140 Ma to ∼52 Ma) with temperatures ranging from ∼53°C to ∼47°C and a cooling rate less than ∼0.1°C Ma, an erosion thickness of ∼300 m and an uplift rate of ∼3 m/Ma; (3) (∼52 Ma to ∼8 Ma) with ∼47°C to ∼43°C and ∼0.1°C /Ma, an erosion thickness of ∼500 m and an uplift rate of ∼11 m/Ma; (3) (∼8 Ma to present) with ∼43°C to ∼20°C and ∼3°C/Ma, an erosion thickness of ∼650 m and an uplift rate of ∼81 m/Ma. The tectonothermal evolutionary history of the Qishan area in Triassic was influenced by the interaction of the Qinling Orogeny and the Weibei Uplift, and the south Qishan area had the earliest uplift‐cooling time compared to other parts within the Weibei Uplift. The early Eocene at ∼52 Ma and the late Miocene at ∼8 Ma, as two significant turning points after which both the rate of uplift and the rate of temperature changed rapidly, were two key time for the uplift‐cooling history of the Permian strata in the Qishan area of the southwestern Weibei Uplift, Ordos Basin.