歧口凹陷古近系沙河街组热液作用及其对湖相碳酸盐岩储层的影响

综合利用岩心薄片观察、流体包裹体和地球化学分析手段,研究歧口凹陷古近系沙河街组沉积时期热液活动对湖相碳酸盐储层物性的控制作用。结果表明:碳酸盐岩地层中广泛发育鞍状白云石,同时伴生黄铁矿和石英;多数碳酸盐岩样品富集轻稀土元素,Eu正异常明显,同时具有较低的87 Sr/86 Sr比值;流体包裹体均一温度普遍高于埋藏时的古地温;研究区热液活动对碳酸盐岩储层有着明显的改造作用。在深部富CO2热液的侵蚀下,碳酸盐岩形成大量溶蚀孔、扩大溶蚀缝和晶间孔,储层物性有着明显的改善;但随之产生的白云岩化作用在一定程度上堵塞已形成的孔隙,给物性带来负面影响;歧口凹陷热液碳酸盐岩储集相被深大走滑断裂所控制,在负花构造部位最为发育,热流体上涌的根源可能为新近系的广泛热事件。     

鄂尔多斯盆地中东部马家沟组白云岩地球化学特征研究

稀土元素分析是一种判别白云岩化流体来源,分析白云岩的形成环境的重要手段。鄂尔多斯盆地中东部白云岩以明显高的Fe含量和低的Na,Sr和Mn含量为特征,白云岩化流体主要为海水或与海水有关,未受或很少受到大气淡水的影响。稀土元素配分图显示所有白云岩样品的曲线形态类似,都呈轻稀土富集和重稀土亏损的右倾模式,且具有Eu负异常和Ce的负异常,δEu平均值为0.45,Ce的平均值为0.35,表明白云岩形成于相对偏碱性还原环境,又受到后期构造热液流体的影响和改造;三类白云岩的的模式都与泥微晶灰岩相近,也说明白云化流体与海水或海源流体相关;综合鄂尔多斯盆地中东部马家沟组白云岩地球化学特征可以判断出区内白云岩的形成环境是相对还原的碱性环境。     

鄂尔多斯盆地南部奥陶系马家沟组中下组合白云岩稀土元素特征及其成因

基于岩石学及稀土元素等特征,开展马家沟组中下组合白云岩储层成因机制研究。结果表明,研究区主要发育泥微晶、粉细晶和细中晶3种类型的白云岩;不同类型白云岩的稀土元素总含量具有一定的差异性,整体含量较低,平均值为13.75×10~(-6),Y/Ho平均值为38.4,主要与沉积与埋藏作用有关;白云岩稀土元素的配分模式均与泥晶灰岩相似,轻稀土元素相对富集,重稀土元素相对亏损,Nd_N/Yb_N的平均值为6.87,δCe值均表现为显著负异常;不同类型白云岩稀土元素Eu异常值具有一定的差异性,泥微晶白云岩δEu值表现为微弱正异常,平均值为1.02,粉细晶白云岩和细中晶白云岩表现为微弱负异常,平均值均为0.96,且多数样品Y和La呈显著正异常,表明泥微晶白云岩形成于相对开放、低氧化性、低温度的局限台地环境,粉细晶白云岩形成于相对封闭、低还原性、弱—中等水动力条件的潮缘浅滩环境,细中晶白云岩形成于相对封闭、低还原性、温度相对较高的潮坪浅滩环境,且主要受回流渗透白云石化作用机制控制。     

黄骅坳陷歧口凹陷古近系沙河街组白云岩特征及成因机制

为了揭示黄骅坳陷歧口凹陷古近系沙河街组白云岩的成因, 本文对64件白云岩样品的岩石学特征、阴极发光程度、碳氧同位素组成和主量元素含量进行了分析研究。岩石学的研究表明，该区白云岩岩石类型为泥晶白云岩、微晶白云岩、藻纹层白云岩和亮晶生物碎屑白云岩。地球化学分析显示，自沙三段至沙一段沉积时期，湖泊的古盐度经历了高-低-高的过程，古气温逐渐降低。泥晶白云岩的铁、锰含量和埋藏温度在4类白云岩中最高，盐度值最低，主要为埋藏成因，形成于还原性较强的低盐度环境中。微晶白云岩的铁、锰含量和埋藏温度相对较低，盐度值相对较高，形成于氧化性较强的近地表高盐度环境中，为渗透回流成因，部分样品受生物发酵作用的影响具有极高的δ13C。藻纹层白云岩的铁、锰含量和埋藏温度相对较高，盐度值在4类白云岩中最高，形成于浅埋藏环境中，成岩环境受海水的影响表现出高盐度特征。亮晶生物碎屑白云岩的铁、锰含量和埋藏温度在4类白云岩中最低，盐度值相对较低，形成于氧化性较强的低盐度浅埋藏环境中，同时受到大气水渗流的影响。     

淮南潘二矿太原组灰岩稀土元素特征及沉积环境的分析

选择淮南潘二煤矿石炭系太原组13层灰岩作为研究对象,在岩石学基础上对其稀土元素地球化学特征进行了分析,并探讨了灰岩中稀土元素的来源,进而对其沉积环境进行解释.结果表明:各层灰岩中Zr,Th,Sc含量较低且Y/Ho比值较高,表明各层灰岩均未受到陆源碎屑物的混染;其中轻稀土(LREE)弱亏损、La正异常、Y正异常、高Y/Ho值呈现出与正常海相碳酸盐岩相似的稀土元素特征,这反映了灰岩沉积环境具有典型海相沉积的特征;δCe反映出各层灰岩沉积时氧化还原条件不同;δEu正异常反映了整个灰岩段沉积时处于近海岸环境,并伴随有陆相有机物质分解风化,进而进入灰岩沉积水体中,从而使Eu呈现显著的正异常.     

贺兰山地区寒武系三山子组白云岩成因

以野外剖面实测与岩石学特征分析为基础,结合碳氧同位数、痕量元素、稀土元素等地球化学分析,对鄂尔多斯盆地贺兰山地区上寒武统三山子组白云岩成因进行了探讨。该区主要发育晶粒白云岩、交代残余结构白云岩和鞍状白云岩,它们的形成受控于埋藏白云石化和构造热液白云石化作用。白云岩主要经历了早期埋藏白云石化、晚期埋藏白云石化和后期构造热液白云石化叠加改造阶段。样品的δ~(18) O值反映其处于相对炎热干燥的环境,且为咸水沉积(wSr/wBa0.8),Sr含量较高。埋藏白云岩主要为晶粒白云岩,样品的δ~(18) O值明显偏负,并显示较强的还原性(wV/wV+Ni≥0.54)。构造热液白云岩发育典型的马鞍状白云石,具有正δEu异常稀土分配模式,多局限在破碎带、断裂带和裂缝带附近。整体碳氧同位素(Z值)120、较低的wTh/wU比值、正δLa异常和弱负δCe异常的稀土分配模式,以及镜下见海百合和腕足类化石,都说明该地区的白云石化流体具有高盐度海源流体的特征。根据岩石学特征和各种地球化学指标,结合古地理背景,建立了研究区埋藏白云石化和构造热液白云石化2种成因模式。     

辽东湾盆地沙河街组湖相白云岩成因研究

辽东湾盆地古近系沙河街组产有一套分布仅限于深凹陷内的深湖相白云岩,岩性主要为泥-微晶白云岩,物质组分以铁白云石为主,在深湖相暗色泥岩中呈很薄的夹层产出,累计厚度6～10 m,产出位置明显受区域内辽中凹陷西界的北北东向基底断裂控制.通过系统的沉积学、岩石学、矿物学和地球化学特征研究,以及与酒西盆地青西坳陷下沟组热水白云岩成因特征对比,认为发育于旅大地区深凹陷内的沙河街组深湖相白云岩也属于罕见的湖相热水沉积岩.     

川西北观雾山组白云岩稀土元素特征及其对白云岩化流体性质的指示

分析川西北地区泥盆系观雾山组白云岩形成过程的流体特征,探讨其形成机理。通过对江油县马角坝、青川县何家梁及平武县甘溪剖面观雾山组白云岩的岩石学特征研究,按照晶粒大小将其分为细-粉晶白云岩、细晶白云岩和中晶白云岩3类;根据稀土元素研究流体性质,推测白云岩成因。白云岩稀土总含量较低,3种白云岩具有相似的稀土配分模式,并且都与泥晶灰岩配分模式类似,表现出轻稀土富集、重稀土亏损;样品均呈现Ce不明显负异常(均值0.94)、Eu负异常(均值0.81)、Y明显的正异常(均值2.98)。稀土元素地球化学特征指示白云岩化流体主要是海源性流体,成岩环境为相对封闭的还原环境。     

青海省祁漫塔格那西郭勒地区条带状铁矿的稀土和微量元素特征

那西郭勒铁矿是近年来东昆仑祁漫塔格古元古代金水口岩群中新发现的沉积变质型铁矿。为探讨那西郭勒铁矿的物质来源、形成环境,以那西郭勒条带状铁矿为研究对象,对矿石微量元素和稀土元素进行了系统测试。结果表明:矿石样品中∑REE和Y具有高度一致的特征,稀土总量较低,为68.51~103.29μg/g,Y/Ho比值较高;经太古界后平均澳大利亚页岩(PAAS)标准化后的稀土元素配分模式呈现重稀土富集、轻稀土亏损的分馏模式,且具有Eu,Y,La的正异常;铁矿石Ti/V比值为19~54.45,明显高于铁质页岩中Ti/V比值,可能与海底火山活动有关;Ni/Co比值平均为1.52,高度一致的Zr和Hf以及V和Sc的正相关。由此可见那西郭勒地区条带状磁铁矿的稀土元素来源为火山热液和海水的混合溶液,尽管磁铁矿的Ce/Ce*比值为0.86~0.92,但样品缺乏真正意义的Ce负异常,指示在铁矿沉积时海水的氧化还原状态为可能缺氧环境。     

歧口凹陷沙一下亚段湖相白云岩岩石学特征及成因分析

 歧口凹陷沙一下亚段白云岩发育在整体湖扩背景下,通过对研究区白云岩镜下鉴定,扫描电镜分析,发现研究区主要发育泥晶白云岩、微晶白云岩、砂质白云岩、灰质白云岩、泥质白云岩5种。结合阴极发光特征、氧同位素、稀土元素实验,揭示了研究区白云岩化作用的2种成因环境：准同生期的回流渗透白云岩化作用、成岩期的埋藏白云岩化作用。通常准同生期的回流渗透白云岩经过深部热液流体的改造,进而发生埋藏白云岩化作用,多见于裂缝发育区。研究区不同地区发育的不同成因的白云岩,对这些白云岩形成类型和形成环境的研究,以及对下一步预测白云岩储层具有重要地质意义。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.