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Earthquake Research Advances 2024年第1期4卷 36-46页

作者： Xinglin Lei Zhiwei Wang Shengli Ma changrong he Geological Survey of Japan AISTTsukuba305-8567Japan State Key Laboratory of Earthquake Dynamics Institute of GeologyCEABeijing100029 China

This study analyzed and summarized in detail the spatial and temporal distributions of earthquakes,tidal responses,focal mechanisms,and stress field characteristics for the M 7.3 Haicheng earthquake sequence in February 1975.The foreshocks are related to the main fault and the conjugate faults surrounding the extension step-over in the middle.The initiation timing of the foreshock clusters and the original time of the mainshock were clearly modulated by the Earth's tidal force and coincided with the peak of dilational volumetric tidal strain.As a plausible and testable hypothesis,we proposed a fluid-driven foreshock model,by which all observed seismicity features can be more reasonably interpreted with respect to the results of existing models.Together with some other known examples,the widely existing step-over along strike-slip faults and associated conjugate faults,especially for extensional ones in the presence of deep fluids,favor the occurrence of short-term foreshocks.Although clustered seismicity with characteristics similar to those of the studied case is not a sufficient and necessary condition for large earthquakes to occur under similar tectonic conditions,it undoubtedly has a warning significance for the criticality of the main fault.Subsequent testing would require quantification of true/false positives/negatives.

关键词： Haicheng earthquake Seismogenic fault ETAS Foreshock Deep fluid

Frictional stability of Longmaxi shale gouges and its implication for deep seismic potential in the southeastern Sichuan Basin

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Deep Underground Science and Engineering 2022年第1期1卷 3-14页

作者： Fengshou Zhang Li Cui Mengke An Derek Elsworth changrong he Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghaiChina Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghaiChina Department of Energy and Mineral Engineering EMS Energy Institute and G3 CenterThe Pennsylvania State UniversityState CollegePennsylvaniaUSA Department of Geosciences The Pennsylvania State UniversityState CollegePennsylvaniaUSA State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijingChina

Microearthquakes accompanying shale gas recovery highlight the importance of exploring the frictional and stability properties of shale gouges.Aiming to reveal the influencing factors on fault stability,this paper explores the impact of mineral compositions,effective stress and temperature on the frictional stability of Longmaxi shale gouges in deep reservoirs located in the Luzhou area,southeastern Sichuan Basin.Eleven shear experiments were conducted to define the frictional strength and stability of five shale gouges.The specific experimental conditions were as follows:temperatures:90–270°C;a confining stress:95 MPa;and pore fluid pressures:25–55 MPa.The results show that all five shale gouges generally display high frictional strength with friction coefficients ranging from 0.60 to 0.70 at the aforementioned experiment condition of pressures,and temperatures.Frictional stability is significantly affected by temperature and mineral compositions,but is insensitive to variation in pore fluid pressures.Fault instability is enhanced at higher temperatures(especially at>200°C)and with higher tectosilicate/carbonate contents.The results demonstrate that the combined effect of mineral composition and temperature is particularly important for induced seismicity during hydraulic fracturing in deep shale reservoirs.

关键词： deep shale reservoir hydraulic fracturing hydrothermal condition induced seismicity mineral composition shale fault stability

水热条件下含橄榄石大洋玄武岩的摩擦特性实验研究

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地球物理学报 2024年第3期67卷 1069-1080页

作者：张钰曼张雷何昌荣中国地震局地质研究所地震动力学国家重点实验室北京100029 西藏自治区地震局拉萨850000

玄武岩作为大洋地壳上的主要成分,研究其摩擦特性是更好地探究逆冲板块边界上大地震等力学行为机理的基础.为了研究少量橄榄石矿物是否会影响玄武岩的摩擦特性,本研究选用了国际大洋钻探计划(IODP)349航次获取的玄武岩样品,其中含有少... 详细信息

玄武岩作为大洋地壳上的主要成分,研究其摩擦特性是更好地探究逆冲板块边界上大地震等力学行为机理的基础.为了研究少量橄榄石矿物是否会影响玄武岩的摩擦特性,本研究选用了国际大洋钻探计划(IODP)349航次获取的玄武岩样品,其中含有少量的橄榄石矿物.本次研究的实验温度范围为100~600℃,施加的有效正压力和孔隙水压分别为150 MPa和100 MPa.实验中玄武岩样品在300~400℃的温度条件下表现出不稳定的准静态震荡现象,并且在高温条件下(T>400℃)其剪切强度表现出显著的位移弱化现象,即摩擦系数随着剪切位移的进行而持续减小.在3 mm的剪切位移范围内,摩擦系数的变化范围为0.7~0.55.通过初步的微观剪切变形研究,我们推测橄榄石在摩擦实验过程中对一种弱矿物的生成可能起到了催化作用,但生成的弱矿物含量不足以显著地弱化断层泥的摩擦强度.同时微观构造分析也发现,随着温度的升高,断层泥的剪切构造由局部剪切向整体弥散性剪切变形转变,同时伴随着孔隙度的显著降低,因此我们认为剪切强度的位移弱化现象与流体参与下的颗粒间的压溶过程的逐步增强有关.

关键词：玄武岩橄榄石摩擦强度摩擦滑动稳定性位移弱化

Microstructures and deformation mechanisms of experimentally deformed gabbro

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Earthquake Science 2015年第2期28卷 119-127页

作者： Yongsheng Zhou changrong he State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration

The natural gabbro samples were deformed at temperature ranging from 700 to 1150 ℃ with strain rate steps of 1 ×10^-4, 2.5 ×10^-5, 6.3 ×10^-6 s^-1. The mechanical data show that sample experiences gradual transition from semi-brittle flow to plastic flow, corresponding to a systematically decreasing stress exponent n with the increasing temperature ranging from 16.5 to 4.1 （he et al. Sci China （D） 46（7）：730-742, 2003）. We investigate microstructures and deformation mechanisms of experimentally deformed gabbro under transmission electron microscope in this study. For low temperature of 700 ℃ to 950℃, the deformation is mainly accommodated with dislocation glide and mechanical twinning, corresponding to stress exponent lager than 5, which means semi-brittle deformation. Whereas with higher temperature up to 1000 ℃-1150 ℃, the deformation is accommodated mainly with dislocation glide and climb corresponding to stress exponent of 4.1, which means plastic deformation. Evidence of dislocation climb has been found as dislocation walls in plagioclase. The observed slip system in plagioclase is （001）1/21110] and that in clinopyroxene are （100）[001] and （010）[001]. The （010）[001] slip system in clinopyroxene is newly found in this work. Melt was found at temperature of 950 ℃-1050 ℃. The melt glass distributed both in melt thin film between two grain boundaries and melt tubules of triangular along three grain boundaries at temperature of 950℃-1000℃. The melt triangular interconnected to the melt film at temperature of 1050 ℃-1150℃, where the melt chemical compositiondifferentiated into iron-rich dark dots and silicate-rich matrix.

关键词： Microstructure Deformation mechanism Transmission electron microscope （TEM） Semi-brittlePlastic Gabbro

Effect of varying normal stress on stability and dynamic motion of a spring-slider system with rate- and state-dependent friction

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Earthquake Science 2014年第6期27卷 577-587页

作者： changrong he Teng-fong Wong State Key Laboratory of Earthquake Dynamics Institute of GeologyCEA Earth System Science Programme Faculty of ScienceThe Chinese University of Hong Kong Department of Geosciences Stony Brook University

Incorporating rate and state friction laws, stability of linearly stable （i.e., with stiffness greater than the critical value） spring-slider systems subjected to triggering perturbations was analyzed under variable normal stress condition, and comparison was made between our results and that of fixed normal stress cases revealed in previous studies. For systems associated with the slip law, the critical mag- nitude of rate steps for triggering unstable slips are found to have a similar pattern to the fixed normal stress case, and the critical velocity steps scale with a/（b - a） when k = kcr for both cases. The rate-step boundaries for the variable normal stress cases are revealed to be lower than the fixed normal stress case by 7 %-16 % for a relatively large ct = 0.56 with （b - a）/a ranging from 0.25 to 1, indicating easier triggering under the variable normal stress condition with rate steps. The difference between fixed and variable normal stress cases decreases when the α value is smaller. In the same slip- law-type systems, critical displacements to trigger instability are revealed to be little affected by the variable normal stress condition. When k 〉 kcr（V,）, a spring-slider system with the slowness law is much more stable than with the slip law,suggesting that the slowness law fits experimental data better when a single state variable is adopted. In stick-slip motions, the variable normal stress case has larger stress drops than the constant normal stress case. The variable normal stress has little effect on the range of slip velocity in systems associated with the slowness law, whereas systems associated with the slip law have a slowest slip velocity immensely smaller than the fixed normal stress case, by ~ 10 orders of magnitude.

关键词： Rate and state friction - Stability Variablenormal stress Stick-slip motion

A fast automatic identification method for seismic belts based on distance correlation and its earthquake case

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Earthquake Science 2020年第3期33卷 153-158页

作者： Wei Yan Xueze Wen changrong he Guiping Liu Zirui Li Institute of Geology China Earthquake AdministrationBeijing 100029China China Earthquake Networks Center Beijing 100045China Beijing Earthquake Agency Beijing 100080China Earthquake Agency of Ningxia Hui Autonomous Region Yinchuan 750001China

Earthquake prediction practice and a large number of earthquake cases show that anomalous images of small earthquake belts may appear near the epicenter before strong earthquakes.Through the research of earthquake cases,researchers have a relatively consistent method to determine the clarity of an identified seismic belt,but there is still a lack of method on seismic belt identification from the distribution of scattered points.Due to the complexity of exhaustive algorithm,the rapid automatic identification technique of seismic belts has been progressing slowly.Visual recognition is still the basic method of seismic belt identification.Based on the algorithm of distance correlation,this paper presents a fast automatic identification method of seismic belts.The effectiveness of this method was proved by 100 random earthquakes and an example of seismic belts of magnitude 4.0 before the 2005 Jiujiang M5.7 earthquake.The results show that:①the automatic identification of seismic belts should first identify the"relational earthquake",then identify the"suspected seismic belt",and finally use the criterion of seismic belt clarity to determine;②random earthquakes and real earthquakes identification results show that the distance correlation method can realize the fast automatic identification of seismic belts by computer.

关键词： seismic belt automatic identification relational earthquake suspected seismic belt belt clarity

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西湖凹陷西部斜坡带原油来源

中国海上油气 2024年第1期36卷 37-48页

作者：王霆何长荣胡合健张铜磊唐友军刁慧何家豪油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院) 湖北武汉430100 中海石油(中国)有限公司上海分公司上海200335

原油来源分析是确定油气勘探方向的重要依据。利用有机地球化学分析手段,分析了西湖凹陷西部斜坡带原油和烃源岩特征,通过生物标志物谱图和生物标志物参数的对比,结合原油与烃源岩分布特征,确定了西湖凹陷西斜坡不同区原油的来源。结果... 详细信息

原油来源分析是确定油气勘探方向的重要依据。利用有机地球化学分析手段,分析了西湖凹陷西部斜坡带原油和烃源岩特征,通过生物标志物谱图和生物标志物参数的对比,结合原油与烃源岩分布特征,确定了西湖凹陷西斜坡不同区原油的来源。结果表明:(1)研究区原油总体上富含指示陆源高等植物输入的生物标志物,但平北地区原油碳同位素重,二萜类丰富,规则甾烷以C29甾烷为主;平湖地区原油碳同位素较轻,二萜类含量较高,且具有较低的伽马蜡烷;黄岩-天台地区原油碳同位素轻,二萜类含量低,规则甾烷以C29甾烷为主,同时C27甾烷的含量也较高。(2)研究区发育煤系烃源岩(包括煤和炭质泥岩)和暗色泥岩两类烃源岩。煤系烃源岩富含来源于裸子植物的异海松烷类和蕨类植物的16β(H)-扁枝烷,从平北到黄岩-天台地区的煤系烃源岩中16β(H)-扁枝烷含量增加;暗色泥岩二萜类含量低,16β(H)-扁枝烷相对于降异海松烷占优势,且从平北到黄岩-天台地区暗色泥岩中C27甾烷、16β(H)-扁枝烷增加。(3)平北地区原油主要为煤系烃源岩贡献,平湖地区原油为煤系烃源岩和暗色泥岩混合贡献,且煤系烃源岩的贡献较大,黄岩-天台地区原油主要为暗色泥岩贡献。研究成果对深化西湖凹陷油源认识及油气勘探部署有一定的指导作用。

关键词：西湖凹陷原油特征煤系烃源岩暗色泥岩二萜类化合物生油母质油源对比

鄂尔多斯盆地陇东地区延长组长9烃源岩展布与潜力评价

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天然气地球科学 2024年第3期35卷 465-478页

作者：张文选王霆邵东波朱建斌何家豪雷宇高小洋何长荣宋浩胡勇中国石油长庆油田分公司勘探事业部陕西西安710018 油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院) 湖北武汉430100 中国石油长庆油田分公司第一采油厂陕西延安716000

为明确鄂尔多斯盆地陇东地区延长组长9烃源岩的勘探潜力,应用有机地球化学方法,结合烃源岩沉积相平面展布特征,开展陇东地区长9烃源岩的烃源岩分相带差异性、地球化学特征及生烃强度研究。结果表明:长9烃源岩普遍发育暗色泥岩,平面展布... 详细信息

为明确鄂尔多斯盆地陇东地区延长组长9烃源岩的勘探潜力,应用有机地球化学方法,结合烃源岩沉积相平面展布特征,开展陇东地区长9烃源岩的烃源岩分相带差异性、地球化学特征及生烃强度研究。结果表明:长9烃源岩普遍发育暗色泥岩,平面展布呈现“沟谷相间”特征,受沉积相控制较为明显。陇东地区长9烃源岩具有较高的有机质丰度,有机质类型以Ⅱ_(1)—Ⅱ_(2)型为主,处于成熟—高熟阶段,整体为中等—好的烃源岩,且长91烃源岩品质优于长92烃源岩。长91烃源岩具有一定的生烃潜力,可以为长8—长9—长10储层供烃,且长9烃源岩生烃强度总体呈现出由南西向北东方向增强的趋势。研究区东北部华池—白豹井区长9烃源岩品质好,生烃强度高,且与附近储层具有较好的运移通道,是该地区长9段石油勘探的有利区。

关键词：鄂尔多斯盆地陇东地区长9油层组烃源岩地球化学特征生烃强度

Water-enhanced plastic deformation in felsic rocks

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Science China Earth Sciences 2013年第2期56卷 203-216页

作者： HAN Liang ZHOU YongSheng he changrong State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake Administration State Key Laboratory for Continental Tectonics and Dynamics Institute of GeologyChinese Academy of Geological Sciences

Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength t

关键词：长英质岩石水分含量塑性变形傅里叶变换红外光谱花岗片麻岩石英含量含水矿物龙门山构造带

Water contents and deformation mechanism in ductile shear zone of middle crust along the Red River fault in southwestern China

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Science China Earth Sciences 2008年第10期51卷 1411-1425页

作者： ZHOU YongSheng he changrong YANG XiaoSong State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

Using Fourier transform infrared spectroscopy (FTIR), we measured water contents of quartz and feldspar for four thin sections of felsic mylonite and two thin sections of banded granitic gneiss col- lected from a ductile shear zone of middle crust along the Red Rivers-Ailaoshan active fault. The ab- sorbance spectra and peak position suggest that water in quartz and feldspar of granitic gneiss and felsic mylonite occurs mainly as hydroxyl in crystal defect, but also contains inclusion water and grain boundary water. The water contents of minerals were calculated based on the absorbance spectra. Water content of feldspar in granitic gneiss is 0.05 wt%-0.15 wt%, and that of quartz 0.03 wt%-0.09 wt%. Water content of feldspar ribbon and quartz ribbon in felsic mylonite is 0.095 wt%-0.32 wt%, and those of fine-grained feldspar and quartz are 0.004 wt%-0.052 wt%. These data show that the water content of weakly deformed feldspar and quartz ribbons is much higher than that of strongly deformed fine-grained feldspar and quartz. This suggests that strong shear deformation leads to breakage of the structures of constitutional water, inclusion and grain boundary water in feldspar and quartz, and most of water in minerals of mylonite is released to the upper layer in the crust.

关键词： hydroxyl in crystal defect grain boundary and inclusion water fourier transform infrared spectrum ductile shear zone deformation mechanism