Earth Science Frontiers ›› 2009, Vol. 16 ›› Issue (4): 97-104.
• Article • Previous Articles Next Articles
State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China
Online:
Published:
Abstract:
In this paper we use the new brittle faulting theory, the “noncoordination criteria”, to expound and analyze the mechanical mechanism of basement preexisting fabric controlling fault formation and evolution, to determine the law of change in preexisting basement fabric activity, and to investigate the controlling role of basement preexisting fabric on fault formation and evolution. Through the study we came to the following conclusions. (1)The basement preexisting fabric (particularly the preexisting fault) has priority in activity, which is the root cause of its control over fault formation and evolution in sedimentary basin. (2)The controlling power of preexisting fabric on basin faulting is determined by its activity that is controlled by the attitude and mechanical property of the preexisting fabric, as well as its stress state, and its activity can be quantitatively described using the activity coefficient (fAS) of preexisting fabric.(3)The faults controlled by basement preexisting fault exhibit remarkable regularity in their locations and trends (strikes), formation orders, inherited features, and the size distributions. (4)The controlling power of basement preexisting fault is the strongest when the fault is perpendicular to the extension direction of the controlled fault and the angle between the preexisting fault and the σ1 of the controlled fault is 45°-(/2); when the angle (α) between the strike of the preexisting fault and the extension direction of the controlled fault becomes smaller gradually, and the dipangle deviated from 45°+(/2), the controlling power will be reduced progressively. (5)The larger the size of the preexisting fault is, the more intensive the controlling power of the preexisting fault on fault formation and evolution will be. The faults controlled by largescale preexisting basement faults tend to constitute the structural framework in rift basin. (6)When the shear strength becoming smaller, the possibility of the occurrence of the rupture in the preexisting weakzone will be increasing, and its controlling power will steadily be enhanced, but its affection is relatively weak comparing to the basement preexisting fault. Using the abovementioned conclusions, a theoretical model for the structural interpretation of seismic data may be constructed. These conclusions may also be used as a theoretical guidance for indepth study of fault system formation and evolution in rift basin.
Key words: Key words: rift basin; fault; preexisting fabric; preexisting fault; activity coefficient; noncoordination criteria
Key words: rift basin; fault; preexisting fabric; preexisting fault; activity coefficient; noncoordination criteria
CLC Number:
P554
TONG Heng-Mao NIE Jin-Yang MENG Lian-Jian ZHANG Gong-Bei LI Xiao-Ning. The law of basement preexisting fabric controlling fault formation and evolution in rift basin.[J]. Earth Science Frontiers, 2009, 16(4): 97-104.
/ Recommend
Add to citation manager EndNote|Ris|BibTeX
URL: https://www.earthsciencefrontiers.net.cn/EN/
https://www.earthsciencefrontiers.net.cn/EN/Y2009/V16/I4/97