Segmentation of Rifts Through Structural Inheritance: Creation of the Davis Strait
Segmentation of Rifts Through Structural Inheritance: Creation of the Davis Strait
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DOI：
10.1029/2019tc005578
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发表时间：
2019-07-01
期刊：
影响因子：
4.2
通讯作者：
Pysklywec, R. N.
中科院分区：
文献类型：
--
作者：
Heron, P. J.;Peace, A. L.;Pysklywec, R. N.
格陵兰岛和北美之间的中新生代裂谷形成了拉布拉多海和巴芬湾，同时在它们之间的戴维斯海峡留下了保存完好的大陆岩石圈。从古元古代碰撞继承的地壳结构已被假设为占这个裂谷系统的构造特征。然而，地幔岩石圈不均匀性在大陆地壳运动中的作用尚未得到充分的探讨。我们的研究使用三维数值模型来分析地壳和地壳下的非均匀性在控制变形中的作用。我们实现了大陆伸展的地幔岩石圈缝合带和变形地壳结构的存在下，并提出了一套模型分析的作用，当地继承有关的地区。特别是，我们调查的地壳和地幔岩石圈疤痕在不断变化的应力制度，保持与板块构造重建的戴维斯海峡的各自作用。数值模拟，第一次，可以重现一阶功能，类似于拉布拉多海，戴维斯海峡，巴芬湾大陆边缘和海洋盆地。地幔岩石圈缝合线的定位，假设存在于古代造山活动，产生一个更合适的构造演化的区域比以前提出的地壳继承。事实上，大陆地幔缝合线相对于伸展方向的平行性在这里被证明是重要的戴维斯海峡的保存。地幔岩石圈非均匀性作为地壳尺度变形的控制因素常常被忽视。在这里，我们强调地壳下层作为一种探索的途径，在理解裂谷系统的演变。
Mesozoic-Cenozoic rifting between Greenland and North America created the Labrador Sea and Baffin Bay, while leaving preserved continental lithosphere in the Davis Strait, which lies between them. Inherited crustal structures from a Palaeoproterozoic collision have been hypothesized to account for the tectonic features of this rift system. However, the role of mantle lithosphere heterogeneities in continental suturing has not been fully explored. Our study uses 3-D numerical models to analyze the role of crustal and subcrustal heterogeneities in controlling deformation. We implement continental extension in the presence of mantle lithosphere suture zones and deformed crustal structures and present a suite of models analyzing the role of local inheritance related to the region. In particular, we investigate the respective roles of crust and mantle lithospheric scarring during an evolving stress regime in keeping with plate tectonic reconstructions of the Davis Strait. Numerical simulations, for the first time, can reproduce first-order features that resemble the Labrador Sea, Davis Strait, Baffin Bay continental margins, and ocean basins. The positioning of a mantle lithosphere suture, hypothesized to exist from ancient orogenic activity, produces a more appropriate tectonic evolution of the region than the previously proposed crustal inheritance. Indeed, the obliquity of the continental mantle suture with respect to extension direction is shown here to be important in the preservation of the Davis Strait. Mantle lithosphere heterogeneities are often overlooked as a control of crustal-scale deformation. Here, we highlight the subcrust as an avenue of exploration in the understanding of rift system evolution.