The timing and cause of mountain building in central Asia

中亚造山的时间和原因

基本信息

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

项目摘要

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.

近 40 年来，板块构造学（地球表面由一些刚性碎片组成，仅在其边缘的窄带内变形的观点）作为对地球表面海洋部分行为的准确描述而被接受。与此同时，同样清楚的是，大陆的行为与海洋板块不同。大陆的变形并不局限于其边缘的窄带，而是通过其内部传播数百公里。一个重要的例子是印度与亚洲的碰撞，形成了从喜马拉雅山到西伯利亚绵延3000公里的山脉。大陆构造研究的一个基本挑战是了解引起观测到的变形的力——研究大陆变形的“动力学”。在我们研究造山的动力学之前，我们必须首先了解变形是如何演变到我们今天所看到的状态的。因此，对造山运动的起始时间及其空间演化提供精确的限制对于理解大陆变形机制至关重要。印度和亚洲之间的碰撞开始于四千五百万年前，在那之后不久就记录了喜马拉雅山和青藏高原内部的变形。众所周知，碰撞带北部主要山脉的起始时间比南部要早得多，但对于整个地理范围而言，这些北部山脉的起始和随后生长的现有限制数量太少，因此，需要研究印度与欧亚大陆碰撞演变的每个阶段的可能原因。我提议对哈萨克斯坦和蒙古西部的天山、准噶尔阿拉套和阿尔泰山脉进行勘察研究。这些山脉构成了印度与亚洲大陆碰撞的最北端部分，目前人们对它们的发展知之甚少。构造演化的约束将来自裂变径迹和 U-Th/He 热测时法。这些技术记录了地球表面 1-3 公里范围内岩石的冷却情况，将与 A. Carter 博士合作实施。特别令人感兴趣的问题是，为什么中亚山脉的变形开始得比喜马拉雅山和西藏晚得多。一种可能的解释是，变形带的宽度逐渐增加，北部山脉的起始年龄较年轻。其他主要的观点是，10-1500万年前青藏高原的快速崛起在亚洲大陆引入了力量，导致造山运动向北推进，或者亚洲太平洋边缘的力量变化导致了变形的重组。大陆内部。通过解开哈萨克斯坦和蒙古西部造山的历史，并通过对其历史每个阶段的时间安排严格的年龄限制，我将能够区分这些不同的情景，以了解负责产生我们的山脉分布的力量。我们选择关注哈萨克斯坦和蒙古西部的造山历史，因为：（1）该地区山脉的构造历史知之甚少，但对于理解造山机制可能非常重要。大陆变形亚洲; （2）山上交通便利，且2011年7月曾到哈萨克斯坦考察，有过旅行经验，有信心在一个野外季节内顺利完成所有采样工作； (3) 我们对蒙古西部阿勒泰地区采集的样本进行的初步测量表明，存在构造上有用的冷却信号。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

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
通讯作者：
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
通讯作者：
E. Ainscoe;K. Abdrakhmatov;S. Baikulov;A. Carr;A. Elliott;C. Grützner;R. Walker

Active Tectonics Around Almaty and along the Zailisky Alatau Rangefront