The rise and fall of Laramide topography and the sediment evacuation from Wyoming

The modern topography within the Laramide region consists of high-relief ranges and high-elevation low-relief (HELR) surfaces separated by intraforeland basins. However, the timing and development of this topography within the type-locality of the Wyoming Laramide province is poorly understood. Previous models suggest that the modern topography is a young feature that was acquired after Laramide tectonism, post-Laramide burial, and basin evacuation; however, evidence of such a progression is sparse. We present low-temperature-thermochronological data from two Laramide uplifts in Wyoming, the Wind River and Bighorn Ranges, which document an early record of Laramide exhumation, subsequent reheating, and significant cooling after 10 Ma. Our results indicate that the Laramide ranges were buried by post-Laramide Cenozoic basin fill, creating a low-relief topography by the early Miocene that was reduced due to late Miocene regional incision and basin evacuation. We suggest that HELR surfaces experienced further relief reduction from Pleistocene glaciation.<br><br> <em>For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to [e-mail]</em> <br>

拉拉米造山带区域内的现代地形由高起伏山脉与高海拔低起伏（high-elevation low-relief, HELR）地表构成，二者被前陆内部盆地分隔。然而，怀俄明拉拉米省典型产地（type-locality）内该地形的形成时间与演化过程尚不清楚。既往模型认为，现代地形是拉拉米构造作用（Laramide tectonism）、拉拉米期后埋藏（post-Laramide burial）以及盆地排空（basin evacuation）之后形成的年轻地貌，但支持该演化过程的证据十分有限。本文报道了怀俄明境内两座拉拉米抬升地块——风河山脉（Wind River Range）与比格霍恩山脉（Bighorn Ranges）的低温热年代学（low-temperature thermochronological）数据，这些数据记录了拉拉米期剥露、随后的再受热以及10 Ma之后的显著冷却过程。研究结果表明，拉拉米山脉曾被拉拉米期后新生代（Cenozoic）盆地充填物所掩埋，至中新世（Miocene）早期形成低起伏地形，随后因晚中新世（late Miocene）区域下切与盆地剥蚀作用，地形起伏得以加剧。本研究提出，HELR地表还因更新世冰川作用（Pleistocene glaciation）进一步降低了起伏程度。<br><br> <em>若对本数据集内容有疑问，请联系README.txt文件中列出的通讯作者（Corresponding Author）。行政类咨询（如移除申请、下载故障等）可发送至[e-mail]</em> <br>