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用于监测四川地区重力场随时间变化的流动重力测网于2008年5月12日汶川MS8.0地震后进行了全面改造， 形成了新的闭合环线并对整网点位每年实施2次重力观测工作. 该文以2010—2012年获取的5期流动重力资料为基础， 分别采用小波多尺度分解和三维视密度反演等位场分离方法， 对测区内重力场的动态变化进行多层次分解及异常特征提取， 以探求四川测区范围内重力异常动态变化特征以及地震前后不同深度范围内密度变化情况与重力场响应之间的关系. 结果表明， 对同一期资料进行小波分解得到不同阶次的细节图像， 揭示了不同深度处重力异常动态变化特征； 分解结果同时也表明了四川测区范围内重力场的变化形态与川内特有的断裂构造格架和深部结构环境及过渡带特征密切相关. 通过对不同时期的差分重力异常资料进行三维视密度反演对比研究发现， 在地震前后四川测区范围内由浅到深密度变化呈现出不同程度的差异， 震区附近出现较为明显的横向密度变化特征且浅层物质密度局部性的异常变化差异较为突出， 测区范围内中上地壳深度层密度反演切片显示出的趋势性差异基本上反映了地震前后测区内地下物质的动态变化趋势， 因此， 深刻认识不同深度范围内重力场的动态演化特征， 对研究壳内物质密度变化以及与地震的孕育和发展有关的深部介质环境具有积极的意义. 相似文献
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Being a part of Jiaoliao anteclise,Jiaodong peninsula
comprises from north to so uth three second－order tectonic units,namely Jiaobei
uplift,Jiaolai (depression ) basin and Jiaonan uplift.In the past,a number of economic
gold deposits were d iscovered in Jiaobei uplift,which can be roughly classified into
altered rock ty pe in the shattered zone (Jiaojia type) and quartz vein type (Linglong
type).In recent years,the authors discovered Pengjiakuang gold deposit and Fayunkuang gol
d deposit on the northeastern margin of Jiaolai basin.The Pengjiakuang gold depo sit
occurs in epi－basin faults with decollement segregation character on the ma rgin of
Jiaolai basin,and the orebodies are consistent with faults in attitude a nd distributed
discontinously along faults in lenticular forms.Individual orebod ies are 300～400 m in
length,0.39～19.45 m in thickness,and have gold grade of 1.0～26.8 g/t;native gold is
disseminated in silicified,phyllic or carbonatize d tectonic breccia,with proved gold
reserves as high as 20 t.The Fayunkuang gold deposit occurs in conglomerate of Early
Cretaceous Laiyang Group on the margin of Jiaolai basin,and the host rocks have been
extensively subjected to silicific a tion,pyritization,sericitization,carbonatization and
chloritization.Orebodies st ratoid in form occur gently (dip angle 10° or so) along
interlayers of conglome rate.Individual orebodies have maximum length of 400 m,oblique
extension of 600～ 700 m and gold grade of 1.0～15.3 g/t,with gold reserves 12 t.Mining
practice r eveals that gold－rich pockets are also controlled by several bed－cutting
fault s of different attitudes. 相似文献
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