石耀霖,
张怀,
中国科学院大学地球与行星科学学院, 计算地球动力学重点实验室, 北京 100049
基金项目: 国家自然科学基金重大项目(41590864, 41590865)资助
详细信息
作者简介: 李伊菲, 女, 1992年生, 博士研究生, 主要从事构造地貌演化数值模拟研究.E-mail:yifeili_1992@126.com
通讯作者: 张怀, 男, 1973年生, 教授, 博士生导师, 主要从事计算地球动力学研究.E-mail:hzhang@ucas.ac.cn
中图分类号: P313收稿日期:2020-04-01
修回日期:2020-08-06
上线日期:2020-10-05
Interaction between tectonic and surface processes: analysis of normal fault scarp morphology and geometric features
LI YiFei,SHI YaoLin,
ZHANG Huai,
Key Laboratory of Computational Geodynamics, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
More Information
Corresponding author: ZHANG Huai,E-mail:hzhang@ucas.ac.cn
MSC: P313--> Received Date: 01 April 2020
Revised Date: 06 August 2020
Available Online: 05 October 2020
摘要
摘要:量化分析构造、侵蚀与气候之间的相互作用关系是现代地球动力学的前沿.断层陡崖是伸展构造环境中的一种常见地貌特征，是构造与地表过程密切耦合作用下演化的结果.断层崖面形态各异，如断层陡坎、断层三角面和断层梯形面等.本文基于数值模拟方法，对断层滑动速率、断层滑动周期、河流下切系数、山坡蠕移系数等关键性控制因素对断层崖形态和几何特征的影响进行了系统分析，主要结论为：依据参数空间的动力学对比模拟结果，可以将断层陡崖分为三个主要类型，即沟壑型、断层三角面型和尖锥型；断层陡崖的最终形态主要受地表演化过程（即河流下切、山坡蠕移）的控制；三角面型陡崖的高度和宽度随时间增大，但坡度角在演化过程中基本不变，其几何特征主要受控于断层滑动速率，且在相同的气候和岩性条件下，与断层滑动速率呈正相关；在十万年时间尺度下，断层滑动周期与三角面的形态和几何特征基本无关.断层滑动速率与三角面坡度角间的正相关关系可用于解释观测数据的统计结果，如希腊和保加利亚的观测数据.
关键词: 正断层陡崖/
断层滑动速率/
地表演化/
数值模型
Abstract:Quantitative analysis of the interaction between tectonics, erosion, and climate is a central topic in modern geodynamics. As a result of tight coupling between the tectonic process and landscape evolution, fault scarps are common features of geomorphology in extensional settings with different shapes, such as scarp, triangle, and trapezoidal facets. In this work, the impact of control factors including average slip rate, recurrence interval, river incision coefficient, and hillslope creep coefficient on the morphology and geometric characteristics of fault scarp are systematically analyzed based on numerical modeling. The result indicates that fault scarp morphology is divided into three types based on parameter sensitivity tests: gully scarp, triangular facet and cone scarp. Two key factors affect the morphology of fault scarp: river incision and hillslope creep coefficient. The height and width of the triangular facet increase with time, whereas the slope is almost fixed. These geometric features are mainly controlled by the average slip rate, which is positively correlated with the fault slip rate under similar long-term climatic conditions and lithology. The morphology and geometric characteristics of a fault scarp are independent of the recurrence interval on the 100, 000-year timescale. The numerical results provide useful insight into the statistical results of observed data such as data in Greece and Bulgaria.
Key words:Normal fault scarp/
Slip rate/
Landscape evolution/
Numerical modeling
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