Location, location, location: The variable lifespan of the Laramide orogeny
Location, location, location: The variable lifespan of the Laramide orogeny
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DOI：
10.1130/g38810.1
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发表时间：
2017-03-01
期刊：
影响因子：
5.8
通讯作者：
Murphy, Michael A.
中科院分区：
文献类型：
--
作者：
Copeland, Peter;Currie, Claire A.;Murphy, Michael A.
的Laramide orthodium有一个空间可变的寿命，我们解释使用地球动力学模型，结合平板俯冲的发生和消亡。拉拉米缩短和伴随的隆升开始于美国加州东南部，大约在1980年。90 Ma，向东北方向移动，在约90 Ma时到达南达科他州（美国）的黑山。60 Ma，南达科他州在大约1000万年内结束。在随后的板片回滚过程中，由于活动变形的东部边缘从约100 °向西南方向迅速后退，Laramide变形的面积范围减小。55至45 Ma，从约55至45 Ma更慢。45至40 Ma，变形最终停止在西南部的造山带在约。30马。这一过程的地球动力学模拟表明，北美板块的强度和致密化的Farallon板块的变化发挥了重要作用，在控制面积范围的Laramide造山带，因此在任何特定的位置在北美西部的造山事件的寿命。
The Laramide orogeny had a spatially variable lifespan, which we explain using a geodynamic model that incorporates onset and demise of flat-slab subduction. Laramide shortening and attendant uplift began in southeast California (USA) at ca. 90 Ma, swept to the northeast to arrive in the Black Hills of South Dakota (USA) at ca. 60 Ma, and concluded in South Dakota within similar to 10 m.y. During subsequent slab rollback, the areal extent of Laramide deformation decreased as the eastern edge of active deformation retreated to the southwest rapidly from ca. 55 to 45 Ma and more slowly from ca. 45 to 40 Ma, with deformation ultimately ceasing in the southwestern part of the orogen at ca. 30 Ma. Geodynamic modeling of this process suggests that changes in the strength of the North America plate and densification of the Farallon plate played important roles in controlling the areal extent of the Laramide orogen and hence the lifespan of the orogenic event at any particular location in western North America.