| 项目编号: | 1650166
|
| 项目名称: | Collaborative Research: Quantifying the Sensitivity of Rifting Processes to Erosion and Sedimentation |
| 作者: | Jean-Arthur Olive
|
| 承担单位: | Columbia University
|
| 批准年: | 2017
|
| 开始日期: | 2017-02-01
|
| 结束日期: | 2019-01-31
|
| 资助金额: | 205750
|
| 资助来源: | US-NSF
|
| 项目类别: | Standard Grant
|
| 国家: | US
|
| 语种: | 英语
|
| 特色学科分类: | Geosciences - Earth Sciences
|
| 英文关键词: | surface process
; process
; rifting
; continental rifting
; study
; active rifting
; magmatic process
; rifting model
|
| 英文摘要: | Rifting is the process by which continents get stretched and ultimately break apart, potentially leading to the formation of a new ocean basin. Active rifting is currently underway throughout large extents of North America, for example within the Basin and Range Province, along the Rio Grande River in New Mexico, and in the Gulf of California. Rifting areas often focus natural resources (e.g., hydrocarbons, metals, geothermal heat) and can be associated with significant seismic hazards. Understanding the processes that shape rift architecture and landscapes is therefore essential on both a fundamental and societal level. This project specifically investigates the sensitivity of two key rifting processes: fault growth and magmatic activity to topographic stresses, which are forces in Earth's crust due to the build-up of topographic relief. Such stresses are known to affect continental deformation where tectonic plates collide (e.g., Taiwan, the Himalayas), but little is known regarding their influence on continental rifting. These stresses are strongly modulated by the erosive action or rivers and glaciers, and the weight of sediments accumulating in basins and lowlands. This study will combine numerical models and field observations to assess how such active surface processes influence fault development and the spatial extent of volcanic activity during rifting. It will support an early-career scientist as well as a minority graduate student. The products of this study will be widely distributed as part of scientific outreach initiatives, and provide material for educators and wilderness conservation areas.
Numerous field and theoretical studies have addressed the feedbacks between surface processes and strain localization in convergent margins at the scale of entire orogens (100?1000 km). However, very little work has been done in extensional settings, where magmatic processes are an integral part of plate boundary evolution, and sizeable topography grows at the scale of individual normal fault-bounded ranges (10?100 km). The goal of this study is to couple existing rifting models with a realistic parameterization of landscape evolution in order to uncover feedbacks between topography growth and tectono-magmatic deformation at depth. Specifically, the project will first document the full range of mass redistribution efficiency in rifts worldwide using a landscape evolution model that allows direct comparison with observables, e.g., the total relief of normal fault footwalls, the morphology of their major catchment basins, and the sedimentary infill of the hanging wall block. We will then implement these calibrated landscape models as an upper boundary condition in a long-term tectonic model where faults can form spontaneously and magmatic intrusions respond to the ambient stress field. A large suite of numerical simulations will enable tests of the following hypotheses: (1) Denudation of the footwall and deposition on the hanging wall are essential in allowing half-grabens to accommodate offsets commensurate with the thickness of the faulted upper crust; (2) Horst formation is promoted by inefficient surface processes, which preserve relief and favor the build up of topographic stresses near the fault; and (3) Efficient redistribution of surficial masses focuses magmatic activity to the rift axis. Model outputs will be systematically compared with field observations of fault growth and volcanic emplacement to identify the contribution of surface processes to the tectono-magmatic evolution of continental rifts. |
| 资源类型: | 项目
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/90574
|
| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
|
|
There are no files associated with this item.
|
| Recommended Citation: | |
Jean-Arthur Olive. Collaborative Research: Quantifying the Sensitivity of Rifting Processes to Erosion and Sedimentation. 2017-01-01.
|
|
|