The timing and cause of mountain building in central Asia

中亚造山的时间和原因

• 批准号: NE/J014141/1
• 负责人: Richard Walker
• 金额: $ 3.7万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ014141%2F1
• 关键词: timing; cause; mountain; building; central

Plate tectonics (the idea that the Earth's surface consists of a few rigid fragments that deform only in narrow bands round their edges) has been accepted for almost 40 years as an accurate description of the behaviour of the oceanic parts of the Earth's surface. At the same time, it has been equally clear that the continents do not behave like the oceanic plates. Deformation in continents is not restricted to narrow bands at their edges, but is spread many hundreds of kilometres through their interiors. A major example is the the collision of India with Asia, which has led to the formation of mountains stretching from the Himalaya to Siberia, over a distance of 3000 km. A fundamental challenge in the study of continental tectonics is to understand the forces that give rise to the observed deformation - the study of the 'dynamics' of continental deformation. Before we can investigate the dynamics of mountain-building we must first develop an understanding of how the deformation has evolved to the state in which we see it today. Providing precise constraints on the times of initiation of mountain-building, and on its spatial evolution, are thus central to understanding the mechanics of continental deformation. The collision between India and Asia began more than 45 Million years ago, and deformation within the Himalaya and Tibetan Plateau is recorded very soon after that time. The initiation of the major mountain ranges in the northern part of the collision zone is known to be much younger than in the south, but the existing constraints on initiation and subsequent growth in these northerly ranges are too few in number for the full geographic extent, and hence the likely cause, of each stage in the development of the evolving India-Eurasia collision to be examined. I propose a reconnaissance study of the Tien Shan, Dzungar Alatau and Altay mountains of Kazakhstan and western Mongolia. These ranges constitute some of the northernmost parts of the collision between the continents of India with Asia, and very little is known of their development at present. Constraints on the tectonic evolution will come from fission-track and U-Th/He thermochronometry. These techniques, which record the cooling of rocks through the top 1-3 km of the Earth undertaking, will be performed in collaboration with Dr. A. Carter. Of particular interest is the question as to why deformation in the mountain ranges of central Asia started much later than in the Himalaya and Tibet. One potential explanation is that the deformation zone is gradually increasing in width, with the initiation ages of mountain ranges younging to the north. Other leading suggestions are that a rapid rise of the Tibetan plateau 10-15 Million years ago introduced forces in the Asian continent that caused mountain-building to step northwards, or that changes in the forces at the Pacific margin of the Asia caused reorganization of deformation within the interior of the continent. By unravelling the history of mountain building in Kazakhstan and western Mongolia, and by placing firm age constraints on the timing of each stage in their history, I will be able to distinguish between these differing scenarios for the forces responsible for producing the distribution of mountains we see at the present day.We have chosen to focus on the history of mountain building in Kazakhstan and western Mongolia because: (1) The tectonic history of the mountain ranges in this area is poorly understood but is potentially very important for understanding the mechanics of continental deformation in Asia; (2) The mountains are easily accessible, and we have experience of travel in Kazakhstan through a reconnaissance visit in July 2011, such that we are confident that all sampling can be completed successfully in one field-season; (3) Our initial measurements from samples collected from the Altay of western Mongolia indicate that tectonically useful cooling signals are present.

板块构造（地球表面由几个仅在狭窄带周围变形的刚性碎片组成的想法）已被接受了将近40年，作为对地球表面海洋部分行为的准确描述。同样，同样清楚的是，大陆的行为不像海洋板那样。大陆的变形不仅限于其边缘的狭窄带，而是通过其内部散布数百公里。一个主要的例子是印度与亚洲的碰撞，这导致了从喜马拉雅山到西伯利亚的山的形成，超过3000公里。大陆构造研究研究中的一个基本挑战是了解引起观察到的变形的力 - 大陆变形的“动力学”的研究。在我们研究山区建设的动态之前，我们必须首先对变形如何发展到今天所看到的状态。因此，在山区建设及其空间进化时提供了精确的限制，因此对于理解大陆变形的机制至关重要。印度和亚洲之间的碰撞始于4500万年前，在那段时间之后很快就记录了喜马拉雅山和藏族高原内部的变形。已知在碰撞区北部的主要山脉的启动比南方年轻得多，但是对这些北端范围的启动和随后的增长的现有限制在整个地理上的数量太少，因此，在不断发展的印度 - eurasia碰撞碰撞的情况下，每个阶段的可能是由于每个阶段的可能性。我建议对哈萨克斯坦和西蒙古的Tien Shan，Dzungar Alatau和Altay Mountains进行侦察研究。这些范围构成了印度与亚洲大洲之间碰撞的最北端部分，目前对它们的发展知之甚少。构造进化的限制将来自裂变轨道和u-th/He Thermochronometry。这些技术将与A. Carter博士合作进行，记录通过地球上1-3公里的岩石冷却。特别值得一提的是，为什么中亚山脉的变形比喜马拉雅山和西藏晚得多。一个潜在的解释是，变形区逐渐增加，北部的山脉范围较年轻。其他领先的建议是，十五万年前藏族高原的迅速上升是在亚洲大陆引入的力量，导致山区建造向北行驶，或者在亚洲太平洋边缘的力量变化导致大陆内部内部变形的重组。 By unravelling the history of mountain building in Kazakhstan and western Mongolia, and by placing firm age constraints on the timing of each stage in their history, I will be able to distinguish between these differing scenarios for the forces responsible for producing the distribution of mountains we see at the present day.We have chosen to focus on the history of mountain building in Kazakhstan and western Mongolia because: (1) The tectonic history of the mountain ranges in该领域的理解很少，但对于理解亚洲大陆变形的机制可能非常重要。 （2）山区很容易到达，我们在2011年7月通过侦察访问在哈萨克斯坦有旅行的经验，因此我们相信所有抽样都可以在一个野外赛季中成功完成； （3）我们从从西蒙古的altay收集的样品中测量的最初测量表明，存在构造有用的冷却信号。

项目成果

Links between climate, erosion, uplift, and topography during intracontinental mountain building of the Hangay Dome, Mongolia

• DOI: 10.1002/2013gc004859
• 发表时间: 2013-12
• 期刊: Geochemistry
• 影响因子: 3.7
• 作者: A. West;M. Fox;R. Walker;A. Carter;T. Harris;A. Watts;B. Gantulga

Variability in surface rupture between successive earthquakes on the Suusamyr Fault, Kyrgyz Tien Shan: implications for palaeoseismology

• DOI: 10.1093/gji/ggy457
• 发表时间: 2018-10
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: E. Ainscoe;K. Abdrakhmatov;S. Baikulov;A. Carr;A. Elliott;C. Grützner;R. Walker

Active Tectonics Around Almaty and along the Zailisky Alatau Rangefront

• DOI: 10.1002/2017tc004657
• 发表时间: 2017-10
• 期刊: Tectonics
• 影响因子: 4.2
• 作者: C. Grützner;R. Walker;K. Abdrakhmatov;A. Mukambaev;A. Elliott;J. Elliott

The Dzhungarian fault: Late Quaternary tectonics and slip rate of a major right-lateral strike-slip fault in the northern Tien Shan region

准噶尔断层：北天山地区一条主要右旋走滑断层的晚第四纪构造和滑动速率

• DOI: 10.1002/jgrb.50367
• 发表时间: 2013
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Campbell G