Active Tectonics of the Africa-Eurasia Zone of Plate Interaction in the Western Mediterranean

西地中海非洲-欧亚板块相互作用带的活动构造

• 批准号: 1419854
• 负责人: Robert Reilinger
• 金额: $ 9.55万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1419854&HistoricalAwards=false
• 关键词: Active; Tectonics; Africa; Eurasia; Zone

The tectonic framework of Morocco is dominated by the interaction between the African and Eurasian plates. Presently, the Nubian Plate moves in a northwest direction with respect to Eurasia resulting in complex collision and strike-slip faulting from the Atlas and Rif Mountains in Morocco to the Betic Mountains in southern Spain. GPS quantification of active crustal deformation in this western Mediterranean region of slow, oblique Africa-Eurasia plate convergence provides new constraints on the mechanics of plate interactions during the final stage of ocean subduction and the initial stages of continental collision. This study will provide new GPS measurements of plate velocities with reduced uncertainties to test competing tectonic models for this enigmatic slow-moving plate boundary. The project advances desired societal outcomes through development of a globally competitive STEM workforce by training of post-doctoral fellow and Moroccan students, development of international collaborations, and research infrastructure enhancement by expansion of a GPS network.This research project will provide new observations necessary to constrain geodynamic processes in the western Mediterranean zone of plate interaction, including active translation and rotation of the Alboran Sea and Moroccan Rif, shortening across and vertical motions in the High Atlas, and strike-slip motion in the Betics of southernmost Spain. Resultant geodetic constraints will distinguish between competing tectonic models: 1) westward rollback associated with the Gibraltar Arc; 2) southward rollback of the subducted Nubian plate, and/or 3) delamination of the continental lithosphere within the collision zone. In collaboration with scientists from Morocco (Centre National pour la Recherche Scientifique et Technique, Universite Mohamad V, Abdelmalek Essaadi University), France (Universite Montpellier), and Spain (Real Instituto y Observatorio de la Armada), this research team will refine present geodetic deformation estimates to better constrain geodynamics across the entire zone of plate interaction. The team will reobserve 6 survey sites, reducing velocity uncertainties by 30 to 50% (to about 0.3 mm/year horizontal, 0.7 mm/year vertical). In addition, the team will establish a new continuous GPS station in the Rif where deformation rates are greatest, reaching about 4 mm/year with respect to stable Nubia. Improved velocity determinations are necessary to constrain vertical motions and estimate internal deformation of the Rif, as well as slip rates on Rif bounding structures, information that is essential to constrain better both the mechanics of active deformation and seismic hazards on active faults. GPS survey sites across the the Middle, High, and Anti-Atlas Mountains will be reobserved, which will result in greater than 50% decrease in velocity uncertainties (to less than 0.3 mm/year horizontal, 0.7 mm/year vertical), providing the first geodetic constraints on vertical motion rates and a two-fold improvement on upper bounds on active shortening across the High Atlas. These improved velocities are necessary to better constrain the role of crustal shortening and subcrustal dynamic processes in maintaining the high elevation of the High Atlas Mountains, and the relationship to dynamic processes along the plate boundary. Analysis, interpretation, and modeling will be undertaken jointly with the international collaborators.

摩洛哥的构造框架以非洲和欧亚板块之间的相互作用为主。目前，努比亚板块在欧亚大陆方面朝西北方向移动，从而导致复杂的碰撞和从摩洛哥的地图集和里夫山脉到西班牙南部的贝蒂奇山脉。在慢速，倾斜的非洲 - 欧洲板融合的慢速地中海地区，GPS量化了活性地壳变形，在海洋俯冲的最后阶段和大陆碰撞的初始阶段为板相互作用的机制提供了新的约束。这项研究将为板速度提供新的GPS测量，并减少不确定性，以测试这种神秘的缓慢移动板边界的竞争构造模型。该项目通过培训博士后和摩洛哥的学生的培训，国际合作的发展以及通过扩大GPS网络的扩展来增强该项目，通过发展全球竞争性的STEM劳动力来推进所需的社会成果。这项研究项目将提供新的观察项目，以限制西部地层杂货的新观察结果，包括限制西地层的旋转式旋转的旋转，包括旋转的旋转。 rif，高地图集的缩短和垂直运动，以及西班牙最南端的滑滑运动。由此产生的大地测量将区分竞争构造模型：1）与直布罗陀弧相关的向西回滚； 2）俯冲的努比亚板的向南回滚和/或3）碰撞区内大陆岩石圈的分层。在与摩洛哥（中心倒入Recherche Scientifique et Technique，Universite Mohamad V，Abdelmalek Essaadi University）的科学家合作的情况下，该研究团队将在跨层次群体上进行互换，该研究团队将精确地估算层次，该研究团队将精确地估算，该研究团队将跨越杂货。该团队将重新观察6个调查站点，将速度不确定性降低30％至50％（约为0.3毫米/年水平，0.7毫米/年垂直）。此外，该团队将在RIF中建立一个新的连续GPS站，其中变形率最高，相对于稳定的Nubia，每年约为4毫米。改善速度确定是必要的，以限制垂直运动和估计RIF的内部变形，以及RIF边界结构上的滑移速率，这对于更好地限制主动变形的机制和主动断层中的抗性危害都是必不可少的。 GPS调查站点将重新观察到中间，高和反式ATLAS山脉，这将导致速度不确定性降低超过50％（低于0.3 mm/年的水平水平，垂直0.7 mm/年），从而在垂直运动率和两倍的运动率上的第一个地理位置约束，并在高度上跨越了高度的高度跨越高度的跨度。这些改进的速度是更好地限制地壳缩短和亚构层动态过程在维持高地图集山高升高以及与沿板边界沿板边界的动态过程的关系的作用所必需的。分析，解释和建模将与国际合作者共同进行。