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.)
The influence of mantle flow on intracontinental basins: Three examples from Australia
Basin Research ( IF 3.2 ) Pub Date : 2020-10-06 , DOI: 10.1111/bre.12520
Alexander Young 1 , Nicolas Flament 1 , Lisa Hall 2 , Andrew Merdith 3
Affiliation  

During the Paleozoic, sedimentary basins developed within Gondwana without evolving to diverging plate boundaries. Such intracontinental basins present long subsidence histories with multiple phases of accelerated subsidence that are not always easily explained by far‐field tectonic forces, and may be driven by processes other than rifting and thermal subsidence. Here we investigate the subsidence of Paleozoic Australian intracontinental basins by comparing one‐dimensional backstripped tectonic subsidence histories from the western Australian Canning and Southern Carnarvon Basins and the central Australian Cooper Basin to forward subsidence models for pure shear lithospheric thinning. We make the hypothesis that differences between observed and model subsidence may be explained by mantle‐flow driven topography, in addition to tectonic forces. To test this hypothesis, we compute dynamic topography from the first geodynamic models of mantle flow spanning the entire Phanerozoic Eon, and we analyse the relationship between dynamic topography and anomalous basin subsidence to dynamic topography and mantle flow. Although reconstructions of mantle flow in deep geological times are uncertain, our results suggest that long‐wavelength dynamic topography could explain aspects of the complex tectonic histories intracontinental basins. In the presented reconstruction of mantle flow, topographic rebound following the sinking of a Cambrian aged slab resulted in a minor phase of dynamic uplift in the Cooper Basin in middle Permian times. Throughout Carboniferous‐Triassic times Australia was positioned above a mantle upwelling driven by a hot structure at the base of the mantle. Structural uplift in the Canning and Southern Carnarvon basins during the Triassic‐Jurassic interval was augmented by dynamic uplift produced by that large‐scale upwelling, and possibly augmented by a focused active mantle plume during the Permo‐Triassic. In Late Jurassic‐Cretaceous times, Australia drifted east away from the mantle upwelling, resulting in a period of subsidence in the Canning and Southern Carnarvon basins. During the Cretaceous the Cooper Basin moved over a downwelling produced by long‐lived subduction along the east Australian margin, resulting in a period of accelerated subsidence.

中文翻译:

地幔流对洲内盆地的影响:澳大利亚的三个例子

在古生代期间,冈瓦纳内的沉积盆地没有演化为发散的板块边界。这类大陆内部盆地具有长期的沉陷历史,并具有多个阶段的加速沉陷,而远期构造力并不总是很容易解释的,而且可能受裂谷作用和热沉陷以外的过程驱动。在这里,我们通过比较西澳大利亚坎宁盆地和南卡那封盆地和澳大利亚中部库珀盆地的一维向后构造构造沉降历史,研究古生代澳大利亚陆内盆地的沉降,以提出纯剪切岩石圈减薄的沉降模型。我们做出这样的假设:除了构造力以外,观测到的沉降与模型沉降之间的差异还可以通过地幔流驱动的地形来解释。为了验证这一假设,我们从跨越整个变生代Eon的地幔流动的第一个地球动力学模型计算了动态地形,并分析了动态地形和反常盆地沉降与动态地形和地幔流动之间的关系。尽管无法确定深部地质时期地幔流的重建,但我们的结果表明,长波动态地形可以解释大陆内部盆地复杂的构造历史。在提出的地幔流重建中,寒武纪陈旧板块下沉后的地形回弹导致了二叠纪中期库珀盆地的动态隆升的次要阶段。在整个石炭纪-三叠纪时期,澳大利亚一直位于地幔上涌的上方,地幔上升源是由地幔底部的高温结构驱动的。在三叠纪—侏罗纪期间,Canning和Carnarvon南部盆地的构造隆升被大规模隆升产生的动力隆升所增强,并且在二叠纪—三叠纪期间可能集中了活跃的地幔柱。在侏罗纪-白垩纪晚期,澳大利亚从地幔上升流向东漂移,在坎宁和南卡那封盆地形成了沉陷期。在白垩纪期间,库珀盆地沿长期的俯冲作用沿东澳大利亚边缘移动到一个向下的井下,导致沉降加速期。在侏罗纪-白垩纪晚期,澳大利亚从地幔上升流向东漂移,在坎宁和南卡那封盆地形成了沉陷期。在白垩纪期间,库珀盆地沿长期的俯冲作用沿东澳大利亚边缘移动到一个向下的井下,导致沉降加速期。在侏罗纪-白垩纪晚期,澳大利亚从地幔上升流向东漂移,在坎宁和南卡那封盆地形成了沉陷期。在白垩纪期间,库珀盆地沿长期的俯冲作用沿东澳大利亚边缘移动到一个向下的井下,导致沉降加速期。
更新日期:2020-10-06
down
wechat
bug