Abstract The southeastern Brazilian passive margin records a complex post-rift evolution, with two parallel high-elevation features formed after the opening of the South Atlantic. We applied apatite fission track (AFT) and U–Th/He (AHe) low temperature thermochronology to constrain the thermo-tectonic history of the Serra do Mar escarpment in the area of Rio de Janeiro state. New AFT central ages for basement areas collected from a N–S transect orthogonal to the shoreline between the cities of Rio de Janeiro and Tres Rios, range between 98.5 ± 5.3 and 54.1 ± 4.2 Ma, with mean track lengths between 12.34 ± 0.40 and 14.63 ± 0.17 μm. Uncorrected AHe ages lie between 68.1 ± 5.9 and 60.2 ± 7.3 Ma and are consistent with AFT results. Inverse thermal history models constrained by AFT and AHe data imply the earliest cooling onset from the Barremian (Early Cretaceous), with steady rates more common for samples closer to coastal areas. Maximum depths of denudation are between 2.5 and 4.5 km. Published thermochronological data from adjacent areas combined with the new results show a seemingly simpler post-rift evolution for the area, although suggesting structural control of age distribution and exhumation.

中文翻译：

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南大西洋被动边缘演化：巴西东南部里约热内卢-特雷斯里奥斯剖面的热年代学案例研究

摘要 巴西东南部被动边缘记录了一个复杂的裂谷后演化，在南大西洋开放后形成了两个平行的高海拔特征。我们应用磷灰石裂变径迹 (AFT) 和 U-Th/He (AHe) 低温热年代学来约束里约热内卢州地区的 Serra do Mar 悬崖的热构造历史。从与里约热内卢市和特雷斯里奥斯市之间的海岸线正交的 N-S 横断面收集的地下室区域的新 AFT 中心年龄介于 98.5 ± 5.3 和 54.1 ± 4.2 Ma 之间，平均轨迹长度介于 12.34 ± 0.40 和 14.63 之间± 0.17 微米。未校正的 AHe 年龄介于 68.1 ± 5.9 和 60.2 ± 7.3 Ma 之间，与 AFT 结果一致。受 AFT 和 AHe 数据约束的逆热历史模型表明巴雷米阶（白垩纪早期）最早开始降温，对于靠近沿海地区的样品，稳定速率更为常见。最大剥蚀深度在 2.5 至 4.5 公里之间。来自邻近地区已发表的热年代学数据与新结果相结合，表明该地区的裂谷后演化看似更简单，但表明年龄分布和挖掘的结构控制。