The geometric and statistical evolution of normal fault systems: an experimental study of the effects of mechanical layer thickness on scaling laws

被引:163
作者
Ackermann, RV
Schlische, RW
Withjack, MO
机构
[1] ExxonMobil Upstream Res Co, Houston, TX 77252 USA
[2] Mobil Technol Co, Dallas, TX 75265 USA
[3] Rutgers State Univ, Dept Geol Sci, Piscataway, NJ 08854 USA
基金
美国国家科学基金会;
关键词
mechanical layer; scaling law; fault systems; experimental modelling;
D O I
10.1016/S0191-8141(01)00028-1
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Detailed analyses of two scaled experimental models of distributed extension that differ only in the thickness of the mechanical layer reveal how normal-fault systems evolve with increasing strain. Faults grow increasingly by linkage and become regularly spaced; the proportion of active structures decreases and converges with that of inactive structures. Large faults contribute increasingly to strain accommodation. The size-frequency distribution of fault lengths changes from power-law (fractal) to exponential, non-linear and dynamic length-displacement scaling arises, and the system becomes less multifractal and more homogeneous. These observations validate many predictions of numerical and geometric models of normal fault growth and system evolution. We propose a generalized three-stage model in which mechanical stratigraphy at times restricts fault growth and the degree of elastic fault interaction. The thickness of the mechanical layer influences the relative timing of stages in this model, as well as the geometry and statistics of the system. As faults encounter and breach multiple mechanical layers, systems may exhibit different scaling attributes at different structural or mechanical levels. Thus, systems may oscillate between different stages of this model, complicating fault-population statistics. We present our data as evidence of the existence of upper and lower bounds for the scale invariant behavior of fault systems, as predicted by Mandelbrot for natural fracture systems. (C) 2001 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:1803 / 1819
页数:17
相关论文
共 93 条
[1]  
Ackermann RV, 1997, GEOLOGY, V25, P1127, DOI 10.1130/0091-7613(1997)025<1127:AOSNFA>2.3.CO
[2]  
2
[3]  
ACKERMANN RV, 1997, THESIS RUTGERS U NEW
[4]  
Ackermann RV, 1999, EOS T AM GEOPHYS UN, V80, pS328
[5]  
ACKERMANN RV, 2001, IN PRESS ASPECTS TRI
[6]  
[Anonymous], 1937, BULL GEOL SOC AM, DOI DOI 10.1130/GSAB-48-1459
[7]  
[Anonymous], 1993, J AGR BIOL ENVIR ST
[8]   Faulting and fault scaling on the median valley floor of the trans-Atlantic geotraverse (TAG) segment, ∼26°N on the Mid-Atlantic Ridge [J].
Bohnenstiehl, DRR ;
Kleinrock, MC .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1999, 104 (B12) :29351-29364
[9]   FAULT GROWTH BY SEGMENT LINKAGE - AN EXPLANATION FOR SCATTER IN MAXIMUM DISPLACEMENT AND TRACE LENGTH DATA FROM THE CANYONLANDS GRABENS OF SE UTAH [J].
CARTWRIGHT, JA ;
TRUDGILL, BD ;
MANSFIELD, CS .
JOURNAL OF STRUCTURAL GEOLOGY, 1995, 17 (09) :1319-1326
[10]   Are fault growth and linkage models consistent with power-law distributions of fault lengths? [J].
Cladouhos, TT ;
Marrett, R .
JOURNAL OF STRUCTURAL GEOLOGY, 1996, 18 (2-3) :281-293