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火山岩储层发育受岩性岩相的控制,为了提高岩性岩相地震识别的精度,选择松辽盆地南部长岭断陷营城组和火石岭组典型钻井火山岩进行井旁地震相分析,分别建立了酸性和中基性火山岩的岩相识别的模版.酸性与中基性火山岩最明显的差别为爆发相和喷溢相之间的差异,酸性岩爆发相具有席状,板状,平行—亚平行反射,连续性好、局部中等,强振幅,低频的特征;酸性岩喷溢相具有楔状、局部透镜,波形反射特征,连续性中—差,中弱振幅、见中强振幅,中高频特征.中基性岩爆发相具有板状,楔状,蠕虫形反射、偶见亚平行反射,中高振幅,中高频,连续性差、见连续性中—好的特征;中基性岩喷溢相具有板状,楔状,平行—亚平行反射、局部波形反射,连续性中等、局部较差,中强振幅,中频、局部高频的特征.根据酸性、中基性火山岩不同的电性特征,结合火山岩段表现的地震内部反射结构,几何形态等地震相特征.总结出不同火山岩之间地震相与测井相的对应关系,为新区识别火山岩相,预测火山岩储层,划分有利储集相带提供依据. 相似文献
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《中国科学:地球科学》2016,(7)
绿岩带是主要形成于太古宙的表壳岩系,下部由大量超基性-基性火山岩构成,上部中-酸性火山-沉积岩逐渐增加.以绿岩带为代表的太古宙表壳岩系占克拉通总体的~30%,记录了早期地球岩浆活动和表生环境的丰富信息,是揭示地壳形成和演化规律的重要研究对象.鲁西是华北克拉通太古宙表壳岩保留较好的地区之一,其主体形成于~2.7和~2.5Ga两个时期,早期表壳岩由泰山岩群下部变科马提岩-玄武岩、少量变碎屑沉积岩和孟家屯岩组变基性岩和变碎屑沉积岩组成,原岩记录的火山岩浆作用与地幔柱有关,反映鲁西在新太古代早期地壳形成具有垂向增生的特点.晚期表壳岩由泰山岩群上部变长英质火山沉积岩、变碎屑沉积岩与少量BIF和济宁岩群变长英质火山岩、变碎屑沉积岩和大规模BIF组成,其中泰山岩群变火山沉积岩的地球化学组成与现代岛弧环境产出的钙碱性岩系类似,指示鲁西的大陆地壳在新太古代晚期可能已发生一定规模的水平运动;鲁西七星台地区变碎屑沉积岩和周围混合岩浅色脉体记录区域高角闪岩相变质-深熔作用的时代可限定在2.53~2.50Ga,与大规模壳熔花岗岩的形成时代一致,标志鲁西在新太古代末已形成统一的陆壳基底. 相似文献
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拉萨地块是研究班公湖—怒江特提斯洋和雅鲁藏布江特提斯洋演化过程的关键,但印度—亚洲大陆的碰撞可能导致拉萨地块遭受不同程度的重磁化影响,为寻找理想地层进行古地磁研究,本文对拉萨地块中二叠世洛巴堆组砂岩、火山岩及灰岩样品进行详细的岩石磁学研究,以确定各类岩石是否具备记录原生剩磁信息的能力.结果表明砂岩样品中主要载磁矿物为磁黄铁矿,火山岩及灰岩样品中主要为磁铁矿或赤铁矿.结合区域地质资料和部分样品退磁实验,本文认为砂岩样品可能遭受林子宗群火山和岩浆活动所提供的区域热扰动影响,记录了古近系重磁化信息;火山岩和灰岩样品可能记录了岩石形成时期的原生剩磁信息,有望从中获得可靠古地磁数据. 相似文献
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阿尔金西段孔兹岩系的发现及岩石学、同位素代学初步研究 总被引:5,自引:0,他引:5
阿尔金西段吐拉一带存在以夕线石榴黑云二长片麻岩、石榴黑云二长片麻岩、含石墨夕线石榴黑云片岩等富铝片麻岩 (片岩 )为主和呈透镜状或薄层状夹于片麻岩 (片岩 )中的石榴角闪二辉麻粒岩等组成的一套孔兹岩系 ,岩石学及地球化学的初步研究表明富铝片麻岩 (片岩 )的原岩为富铝泥质和泥砂质沉积岩 ,所夹基性麻粒岩的原岩可能为大陆拉斑玄武岩 ,这套孔兹岩系的原岩可能形成于大陆边缘环境 .孔兹岩系经历了麻粒岩相的变质作用 ,矿物的温压估算得到其峰期变质温度为 70 0~ 85 0℃ ,压力为 0 .8~ 1.2GPa .岩石中变质锆石的U Pb及Pb Pb同位素测定获得447~ 46 2Ma的年龄值 ,代表其麻粒岩相的变质作用时代 .从富铝片麻岩中含继承组分的锆石还获得较老的上交点年龄 ,它可能代表其沉积岩原岩源区的年龄 相似文献
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随州花山蛇绿构造混杂岩的厘定及其大地构造意义 总被引:16,自引:4,他引:16
地质、地球化学综合研究证明 ,在秦岭造山带南缘襄 (樊 ) 广 (济 )断裂带的三里岗 三阳区段残存有花山蛇绿构造混杂岩 ,是以多条断裂和韧性剪切带为骨架 ,剪切包容花山蛇绿岩块、小阜岛弧火山岩、深海沉积岩、弧前沉积以及来自两侧陆块的基底和盖层沉积岩块 .地球化学研究表明 ,花山蛇绿岩的玄武质岩石类似于MORB的性质 ,形成于初始小洋盆构造环境 ;小阜火山岩形成于岛弧构造环境 .该混杂岩带因存在蛇绿岩及岛弧火山岩而成为具有重要大地构造意义的蛇绿构造混杂岩 ,指示曾存在古板块构造缝合带 ,标志着南秦岭与扬子板块之间确曾存在过古洋盆———花山小洋盆 . 相似文献
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中国东部中新生代断陷盆地群发现了大量的原位火山岩油气藏.以松辽盆地早白垩世徐家围子断陷为例,钻井揭示结果及地质、地球物理综合分析表明,原位火山岩油气藏形成机制具有"断控体、体控相、相控储、储控藏"的特点,即深大断裂样式控制火山岩喷发方式决定火山岩体及气藏分布,火山岩体控制火山岩相带的展布空间决定火山岩油气藏规模,火山岩相控制储层物性的优劣决定油气层的有效厚度,火山岩储层物性控制油气藏类型决定火山岩油气层产能.研究认识对指导断陷盆地原位火山岩油气藏的发现具有理论和实践意义. 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
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《地震工程与工程振动(英文版)》2014,(4)
正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and 相似文献
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George W. Housner 《地震工程与工程振动(英文版)》2008,7(2):I0001-I0001
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States. 相似文献
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《国际泥沙研究》2014,(4)
正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study 相似文献
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JianCheng Shi 《中国科学:地球科学(英文版)》2014,57(10):2281-2282
正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases 相似文献
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O. Martins 《水文研究》1988,2(1):19-29
Water quality analyses for the Niger River for the 1980/81 hydrological year are presented. The samples were collected from the main river at Lokoja, and from two main tributaries, the Kaduna and the Benue Rivers. Different water types were distinguished by the concentrations of major ions. The type Ca > Na > Mg > K - HCO3 > SO4 > Cl was represented at all stations during at least part of the year. Chloride was found to dominate the sulphate ion in the Kaduna and Niger, while the Benue maintained a higher concentration of sulphate relative to chloride all year round. Distinct patterns of seasonal variation in the ion concentrations were observed, particularly for the samples collected at Lokoja. Low ion concentrations were prominent during periods of high discharge, while low flow periods coincided with high dissolved ion concentrations. The contribution of rainwater to the total dissolved solids in the river waters was assessed indirectly using rainwater chemistry data from the Gulf of Guinea. The estimated rainwater contribution to the Lower Niger amounts to 5.15 mg 1?1. Geochemical weathering calculations involving reactions of the four major minerals of granitic rocks - anorthite, biotite, albite, and K-feldspar - with carbon dioxide and water, can account for the average water composition of the Lower Niger. The proportion of the ionic components was also related to the occurrence of the respective element in the minerals. 相似文献