当前位置: X-MOL 学术Basin Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Detrital apatite geochemistry and thermochronology from the Oligocene/Miocene Alpine foreland record the early exhumation of the Tauern Window
Basin Research ( IF 2.8 ) Pub Date : 2021-08-12 , DOI: 10.1111/bre.12593
Julian Hülscher 1 , Edward R. Sobel 2 , Vincent Verwater 1 , Philip Groß 3 , David Chew 4 , Anne Bernhardt 1
Affiliation  

The early exhumation history of the Tauern Window in the European Eastern Alps and its surface expression is poorly dated and quantified, partly because thermochronological and provenance information are sparse from the Upper Austrian Northern Alpine Foreland Basin. For the first time, we combine a single-grain double-dating approach (Apatite Fission Track and U-Pb dating) with trace-element geochemistry analysis on the same apatites to reconstruct the provenance and exhumation history of the late Oligocene/early Miocene Eastern Alps. The results from 22 samples from the Chattian to Burdigalian sedimentary infill of the Upper Austrian Northern Alpine Foreland Basin were integrated with a 3D seismic-reflection data set and published stratigraphic reports. Our highly discriminative data set indicates an increasing proportion of apatites (from 6% to 23%) with Sr/Y values <0.1 up-section and an increasing amount of apatites (from 24% to 38%) containing >1,000 ppm light rare-earth elements from Chattian to Burdigalian time. The number of U-Pb ages with acceptable uncertainties increases from 40% to 59% up-section, with mostly late Variscan/Permian ages, while an increasing number of grains (10%–27%) have Eocene or younger apatite fission track cooling ages. The changes in the apatite trace-element geochemistry and U-Pb data mirror increased sediment input from an ≥upper amphibolite-facies metamorphic source of late Variscan/Permian age – probably the Ötztal-Bundschuh nappe system – accompanied by increasing exhumation rates indicated by decreasing apatite fission track lag times. We attribute these changes to the surface response to upright folding and doming in the Penninic units of the future Tauern Window starting at 29–27 Ma. This early period of exhumation (0.3–0.6 mm/a) is triggered by early Adriatic indentation along the Giudicarie Fault System.

中文翻译:

来自渐新世/中新世高山前陆的碎屑磷灰石地球化学和热年代学记录了陶恩窗的早期挖掘

欧洲东阿尔卑斯山 Tauern Window 的早期挖掘历史及其表面表现的年代和量化都很差,部分原因是来自上奥地利北部高山前陆盆地的热年代学和来源信息很少。我们首次将单粒双测年方法(磷灰石裂变径迹和 U-Pb 测年)与对相同磷灰石的微量元素地球化学分析相结合,重建渐新世晚期/中新世早期东部的物源和折返历史。阿尔卑斯山。来自上奥地利北部高山前陆盆地 Chattian 至 Burdigalian 沉积填充物的 22 个样品的结果与 3D 地震反射数据集和已发表的地层报告相结合。我们高度区分的数据集表明,Sr/Y 值 <0.1 向上截面的磷灰石比例越来越高(从 6% 到 23%),以及含有 >1,000 ppm 轻稀土的磷灰石数量越来越多(从 24% 到 38%)。从查特到布尔迪加尔时代的地球元素。具有可接受不确定性的 U-Pb 年龄数量从 40% 增加到 59%,主要是晚瓦利斯坎/二叠纪年龄,而越来越多的颗粒(10%–27%)具有始新世或更年轻的磷灰石裂变径迹冷却年龄。磷灰石微量元素地球化学和 U-Pb 数据的变化反映了来自晚瓦里坎/二叠纪晚期角闪岩相变质源(可能是 Ötztal-Bundschuh 推覆系统)的沉积物输入增加磷灰石裂变径迹滞后时间。我们将这些变化归因于从 29-27 Ma 开始的未来 Tauern 窗口的 Penninic 单元中直立折叠和隆起的表面响应。早期的剥露期 (0.3-0.6 mm/a) 是由沿 Giudicarie 断层系统的早期亚得里亚海压痕触发的。
更新日期:2021-08-12
down
wechat
bug