New 26Al/10Be and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley
New 26Al/10Be and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley
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DOI：
10.1016/j.geomorph.2020.107448
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发表时间：
2020-10
期刊：
影响因子：
3.9
通讯作者：
W. Odom;F. Hofmann;R. V. Arsdale;D. Granger
中科院分区：
文献类型：
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作者：
W. Odom;F. Hofmann;R. V. Arsdale;D. Granger
高地复合体是古老的密西西比河的一个广泛的阶地。它在上新世密西西比河流域的研究以及密西西比河流域中部的隆起和地震活动方面发挥了核心作用。先前对高地杂岩年代测定的努力已经产生了一系列从中新世到更新世的年龄估计。我们使用26 Al/10 Be埋藏测年和（U-Th）/He地质年代学对阿肯色州、肯塔基州、密西西比和田纳西州的高地杂岩采石场的砾石和氧化铁胶结物进行了测年。我们的26 Al/10 Be埋藏日期显示可能上新世至更新世的沉积年龄，而（U-Th）/He测年表明，风化的开始日期至少上新世。综合考虑，26 Al/10 Be和（U-Th）/He年龄限制表明，高地复杂的年龄至少是上新世，并可能形成在一个长期的基准面稳定更新世冰期之前。
The Upland Complex is a widespread terrace of the ancestral Mississippi River. It has played a central role in studies of the Pliocene Mississippi River drainage, as well as uplift and seismicity in the central Mississippi River Valley. Previous efforts to date the Upland Complex have yielded a range of age estimates spanning the Miocene through Pleistocene. We dated gravels and Fe-oxide cements from quarries of the Upland Complex in Arkansas, Kentucky, Mississippi, and Tennessee using26Al/10Be burial dating and (U-Th)/He geochronology. Our26Al/10Be burial dates revealed possible Pliocene-to-Pleistocene depositional ages, while (U-Th)/He dating showed that the onset of weathering dates to at least the Pliocene. Taken together, the26Al/10Be and (U-Th)/He age constraints demonstrate that the Upland Complex is at least Pliocene in age, and likely formed during a prolonged period of base level stability that preceded Pleistocene glaciations.