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磷灰石裂变径迹(AFT)分析表明,合肥盆地北部K12砂岩的AFT年龄为(128.2±9.5)Ma,围限径迹长度为(11.9±0.4)μm。其模拟热史包括4个阶段:在距今175~150Ma,冷却速率为8.92℃/Ma;在距今150~85Ma为0.99℃/Ma;在距今85~24Ma为-0.49℃/Ma;在距今24Ma以来为1.96℃/Ma,它们依次对应于物源区快速抬升剥露、缓慢抬升剥露以及盆地先沉降后抬升4个阶段。盆地南缘黑石渡组(K1h)的AFT年龄为(86.3±4.3)Ma,平均围限径迹长度为(13.6±0.2)μm。模拟热史表明,在距今135~122Ma时冷却速率为-13.60℃/Ma;在距今122~98Ma时为1.92℃/Ma;在距今98~90Ma时为6.63℃/Ma;在距今90~26Ma时为0.88℃/Ma;在距今26Ma以来为0.69℃/Ma,它们依次与沉积埋藏加热、缓慢抬升剥露、快速抬升剥露以及两次缓慢剥露5个阶段相对应。合肥盆地的演化先后受到大别造山带与郯庐断裂带构造活动的控制:即盆地挤压阶段(早侏罗世至距今150Ma)受控于大别山晚造山期挤压环境,盆地伸展断陷阶段(距今150~138Ma)受控于大别山造山根拆沉作用,盆地滑覆冲断-走滑阶段(距今138~90Ma)受控于造山带热窿伸展与郯庐断裂走滑联合作用,盆地走滑拉张阶段(距今90~25Ma)受控于郯庐断裂带走滑拉张作用,盆地挤压抬升阶段(距今25Ma以来)受控于郯庐断裂带挤压环境。
Apatite fission track (AFT) analysis shows that the AFT age of K12 sandstone in the northern Hefei Basin is (128.2 ± 9.5) Ma and the length of perimeter track is (11.9 ± 0.4) μm. The simulated thermal history consists of four stages: in the past 175 ~ 150Ma, the cooling rate is 8.92 ℃ / Ma; in the past 150 ~ 85Ma is 0.99 ℃ / Ma; 1.96 ℃ / Ma since 24 Ma, which correspond to rapid uplift and exhumation in the provenance area, slow uplift and revelation, and uplifting in the basin after 4 stages. The AFT age of the Heishidudu Formation (K1h) in the southern margin of the basin was (86.3 ± 4.3) Ma, and the average length of the perimeter track was (13.6 ± 0.2) μm. The simulated thermal history shows that the cooling rate is -13.60 ℃ / Ma at 135 ~ 122Ma, 1.92 ℃ / Ma at 122 ~ 98Ma, 6.63 ℃ / Ma at 98 ~ 90Ma, 0.88 ℃ / Ma at 90 ~ 26Ma and 0.69 ℃ / Ma since 26Ma, which correspond to the five stages of burial and deposition, slowly rising and exfoliating, rapid rising and exfoliation, and two slow exfoliation. The evolution of the Hefei Basin has been controlled by the tectonic activities of the Dabie orogenic belt and the Tanlu fault zone. The basin compression stage (from the Early Jurassic to the present 150 Ma) is controlled by the late orogenic extrusion in the Dabie Mountains, Stage (dating back to 150 ~ 138Ma) is controlled by the orogenic debonding in the Dabie Mountains. The slip-slip-slip phase (138 ~ 90Ma) of the basin is controlled by the combination of the hot orbit extension of the orogenic belt and the strike-slip of the Tanlu fault The strike-slip extension stage of the basin (90 ~ 25Ma ago) is controlled by the strike-slip tearing of the Tancheng-Lujiang fault zone. During the stage of crustal uplift (since 25Ma), the basin is controlled by the crushing environment of the Tanlu fault zone.