Apatite fission‐track ages of 168–83 Ma for 39 samples of Proterozoic crystalline rocks, three samples of Cambrian Potsdam sandstone, and one Cretaceous lamprophyre dike from the Adirondack Mountains in New York State indicate that unroofing in this region occurred from Late Jurassic through Early Cretaceous. Samples from the High Peaks section of the Adirondack massif yielded the oldest apatite fission‐track ages (168–135 Ma), indicating that it was exhumed first. Unroofing along the northern, northwestern, and southwestern margins of the Adirondacks began slightly later, as shown by younger apatite fission‐track ages (146–114 Ma) determined for these rocks. This delay in exhumation may have resulted from burial of the peripheral regions by sediment shed from the High Peaks. Apatite fission‐track ages for samples from the southeastern Adirondacks are distinctly younger (112–83 Ma) than those determined for the rest of the Adirondack region. These younger apatite fission‐track ages are from a section of the Adirondacks dissected by shear zones and post‐Ordovician north‐northeast‐trending normal faults. Differential unroofing may have been accommodated by reactivation of the faults in a reverse sense of motion with maximum compressive stress, σ1, oriented west‐northwest. A change in the orientation of the post–Early Cretaceous paleostress field is supported by a change in the trend of Cretaceous lamprophyre dikes from east‐west to west‐northwest.

中文翻译：

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由磷灰石裂变径迹热年代学确定的纽约州阿迪朗达克山脉差异开顶的证据

39 个元古代结晶岩样品、3 个寒武系波茨坦砂岩样品和 1 个来自纽约州阿迪朗达克山脉的白垩纪萤石岩脉的磷灰石裂变径迹年龄为 168-83 Ma，表明该地区从晚侏罗纪到早白垩纪。来自阿迪朗达克地块高峰部分的样本产生了最古老的磷灰石裂变轨迹年龄（168-135 Ma），表明它首先被挖掘出来。阿迪朗达克山脉北部、西北部和西南边缘的开顶开始稍晚，如为这些岩石确定的较年轻的磷灰石裂变轨道年龄（146-114 Ma）所示。这种挖掘延迟可能是由于从高峰期脱落的沉积物掩埋了周边地区。阿迪朗达克东南部样品的磷灰石裂变径迹年龄明显比阿迪朗达克地区其他地区确定的更年轻（112-83 Ma）。这些年轻的磷灰石裂变径迹年龄来自阿迪朗达克山脉的一部分，被剪切带和后奥陶纪北-东北向正断层切割。差异开顶可能是通过以最大压缩应力 σ1 向西北偏西方向的反向运动重新激活断层来适应的。白垩纪斑岩岩脉从东西向西-西北方向的变化支持了早白垩世后古应力场方向的变化。这些较年轻的磷灰石裂变径迹年龄来自阿迪朗达克山脉的一部分，被剪切带和后奥陶纪北-东北向正断层切割。差异开顶可能是通过以最大压缩应力 σ1 向西北偏西方向的反向运动重新激活断层来适应的。白垩纪斑岩岩脉从东西向西-西北方向的变化支持了早白垩世后古应力场方向的变化。这些较年轻的磷灰石裂变径迹年龄来自阿迪朗达克山脉的一部分，被剪切带和后奥陶纪北-东北向正断层切割。差异开顶可能是通过以最大压缩应力 σ1 向西北偏西方向的反向运动重新激活断层来适应的。白垩纪斑岩岩脉从东西向西-西北方向的变化支持了早白垩世后古应力场方向的变化。