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1.
Xiamen Western Bay‘s water and sedimem quality were studied by detemaining thelevels of sixteen polycyclic amrrmtic hydrocarbons PAHs in water, porewater and sediment samples from nine locations in the bay. Total PAH concentrations varied from 106 to 945 ng/1 in water, below detectionto 3548 ng/1 in porewater, and 247 to 480 ng/g dry weight in surface sediments. PAHs levels in porewaterwere higher than those in surface water, due to the preference of these hydrophobic compounds for sedimentary phase instead of water. Such a concentration gradient implies a potential flux of pollutants fromsediments to overlying water. The PAils levels in sediments were one to several orders of magnitude lowerthan those in 1993, suggesting their decreased input in recent years and possible degradation with time.  相似文献   

2.
矿业是广西国民经济的支柱产业 ,在西部大开发中 ,必须认清矿业发展面临的形势 ,研究对策 ,才能作出新贡献。  相似文献   

3.
INTRODUCTIONColloids (orsub micrometerparticles)areoperationallydefinedasparticlesbetween 1nmand1 μm (Vold ,R .D .andVold ,M .J.,1 983) .Thedistributionbetween“dissolved”and“particu late”phaseinaquaticchemistryusedtobedefinedbyafiltrationwith 0 .45 μmporesizefilters.Th…  相似文献   

4.
INTRODUCTIONDredgedmatterisamixtureofmuddysandandmarinewater,andinitiallyvariesnormallyindensityfrom 1 .2to 1 .5g cm3accordingtothedredgeequipmentemployedandtheseabedproper ty.Afterdredgedmatteronaboathasbeendischargedatafixedpoint,itssettlingpropertiescanbe…  相似文献   

5.
在豫西伊川—汝阳两县交界地区,出露一套新生代玄武岩。该玄武岩以低硅富碱和钛为特征,属轻稀土元素富集型。玄武岩岩石化学成分比较均一,以碱性橄榄玄武岩为主,微量元素镍和铬含量低,这些特征指示了该玄武岩属上地幔低度部分熔融产生的原生岩浆快速喷出地表的产物。岩浆在上升运移过程中,没有发生明显的分离结晶和同化混染作用,起源于60~85km的上地幔范围。  相似文献   

6.
本文用细化了的重力和地形综合数学模型、双层锯齿形计算模板、给定区域方差—协方差函数的最小二乘配置小区域内插和精度限定等精算重力异常场值的方法,以不低于±2.4×10~(-5)ms~(-2)和±2.9×10~(-5)ms~(-2)的精度,分别获得了滇西试验场区(99°E~102°E,24°N~27°N)最新完全布格重力异常和均衡重力异常展布图。依该区地震分布与重力场变异特征的对比研究,将下关—洱源—剑川一线划为7~7.5级地震潜在源区,永胜—大姚北划为6.5—7级地震潜在源区。  相似文献   

7.
本文使用Nakai预处理和Venedikov调和分析方法,对滇西地区下关台GS15-227重力仪1987-1992年观测资料和丽江台ET-22重力仪1991-1992年的观测资料进行了分析处理,并对其计算结果进行了仪器动力学特征及惯性和海潮负荷改正,进而确定滇西地区潮汐基准参数为:δ(01)=1.166±0.001,δ(M2)=1.163±0.000,(01)=-0.38±0.08,(M2)=-0.32±0.08  相似文献   

8.
本文以酒西盆地侏罗—白垩系储油层为例,对低渗透砂岩及孔隙—裂隙双重介质储集层的孔隙结构进行了较详尽的研究,并对其某些特征参数进行了计算,进而试图从其宏观和微观规律入手查明该储层的储集特征、分布规律及其影响因素,以达到指导油田今后勘探和开发的目的。  相似文献   

9.
综述了湛江港、雷州湾的地理环境、气候、海岸水文、水化、水产资源等基本情况,介绍了鱼、虾、贝、藻的生产历史和现状,提出了资源开发利用的建议。  相似文献   

10.
白术沟组以其独特的岩石物理特性而卷入到推覆构造带的特殊部位。本文研究了白术沟组的三种构造位态,确定其主要呈第一种构造位态广泛分布于推覆体内部某次一级逆冲滑脱断层的下部,其上覆逆冲岩席由震旦系栾川群及中元古界官道口群构成,下伏地层为下古生界陶湾群。前人将白术沟组置于栾川群的底部层位,笔者对此提出异议,认为以含磷、铀为特征的白术沟组碳质千枚岩层实与我省北部华北地台区早寒武世辛集组底部含磷铀的碳泥质层为同一层位,同样的地层也见于确山西部的“银洞沟组”及大别山的“商城群”石门冲组含磷层中。  相似文献   

11.
辽宁西部地区中生代白垩纪存在两期火山旋回,时代分别属早白垩世早期和中白垩世早期。早白垩世火山旋同即义县组,中白垩世火山旋回本文称为大兴庄火山岩,该期火山岩火山活动微弱,火山岩分柑局限,主要出露于阜新—义县盆地的东侧上齐台一带,以宁静的侵出和次火山岩侵入为主,是早白垩世阜新组沉积之后,中白垩世孙家湾组沉积之前的一次火山活动,它与孙家湾组共同组成一个火山喷发—沉积旋回。  相似文献   

12.
本文介绍近年来在浙西石耳山花岗岩区引进“花岗岩超单元─单元”理论进行的1:5万区域地质调查工作取得的成果。按同源岩浆演化序列的观点,通过野外工作和室内研究,解体了晋宁期石耳山复式花岗岩体。对划分出的30个侵入体,归并建立了四个单元,并进一步建立了石耳山超单元。通过对石耳山超单元花岗岩的岩石矿物学、岩石化学、地球化学等地质特征的分析研究,初步总结其演化特征,并同时探讨其成因类型,指出石耳山超单元花岗岩相当于S型花岗岩,应属上地壳硅铝层重熔岩浆的产物。  相似文献   

13.
辽西火山岩型金矿分布在中生代陆相火山盆地边缘活动带内,受辽西弧形构造带控制,为火山期后热液矿床,可初步划分为3种成因类型:次火山(斑岩)热液型(二道沟式),火山—次火山热液型(红石砬子式)和爆发角砾岩型(水泉式),成矿作用与中酸性火山—次火山岩关系密切,成矿时代为燕山期(90—110Ma)。稳定同位素研究结果表明,含矿热液为富含挥发组份和多金属成矿元素的富金水溶液,来源于地壳深部或上地幔,即高温热卤水对镁铁质、超镁铁质岩石长期侵蚀、淋滤和溶解,获取大量的金属成矿元素,在不透水层之下形成深部液态矿源层。  相似文献   

14.
I.INTROIjUCTIONSincethereformandopening-up,FOreignDirectinvestments(FDIs)havebeenemployedinChineseeconomicdevelopment.SomeresearchresultsshowthatFDIsinChineseeconomicdevelOPmenthavechangedaseriesofeconomicstructure,suchas,investmentstructure,propertystructtire,tradestructure,technologystructureetc.whichsuggeststhatrolesofaflsinChineseeconomicdevelopmentshouldbeseriouslytakenintoconsiderationinstudyingtheregionaldevelopmentissues.Evidently,theregionaldifferenceofrolesofFDIsisdetendn…  相似文献   

15.
豫西金矿为国内外地质界所瞩目,金矿田构造研究的理论、方法和手段达到了国内外先进水平。其研究的基本内容包括构造层控矿特征、控矿构造类型、控矿构造体系和构造分带性、控矿构造发展阶段、成矿热液圈闭条件、矿液流向及导矿构造的研究等。其研究方法包括传统地质构造、地球物理、构造地球化学、航片遥感解译、数学地质和电算技术等方法。其发展趋势是矿田构造研究的新理论、新方法、新技术手段将得到广泛应用,由单一矿床(田)构造研究发展到更大区域内构造体系的研究,构造控矿因素与其他控矿因素相结合进行综合研究,控矿构造类型的研究将有所突破,基础地质构造研究将永远占主导地位,矿田构造研究的成果将被广泛应用于找矿工作。  相似文献   

16.
北秦岭西段地处秦岭造山带和祁连造山带的接合部位,是构造岩浆活跃地带,特别是中生代构造岩浆活动形成了该地段中生代构造岩浆带。北秦岭西段是金矿(化)集中的地带,控矿的主要因素可以归结为下列几个方面:①区域地质构造背景;②区域地球化学场;③构造断裂;④构造岩浆活动;⑤流体地质。这五种因素共同作用决定了金及相关元素的迁移富集,形成了规模不等、类型各异的金矿床及金矿化点。  相似文献   

17.
文章分析对比了桂西地区Au、As、Hg、Sb元素的时空区域分布,并经与岩石样对比,发现上古生界以碳酸盐岩为主的地层为高背景,三叠系为低背景,Au的高背景区呈NW向展布,这与右江裂谷区地壳演化的独特历史有关。桂西地区上古生界金主要来自深源,三叠系碎屑岩中金主要来自陆源。从Au元素丰度与存在形式考虑,高背景的碳酸盐岩夹泥岩、硅质岩、火山岩建造及毗邻的碎屑岩对金成矿更有利。  相似文献   

18.
INTRODUCTIONTheproductionofphytoplanktonisthefirsttacheintheproductionbymarineorganismsandinthemarinefoodchain .Knowledgeofprimaryproductioninmarinewatersisprerequisiteforexploitationandmanagementoftheocean’slivingresources.Theprimaryproductioninmarin…  相似文献   

19.
Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou B ay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO-3-N, NO-2-N, NH+4-N, SiO2-3-Si, PO3-4-P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temp erature; that the main factor controlling the primary production is Si; that water temper ature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecologica l niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature's effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay , the biogeochemical sediment process of the silicon, the phytoplankton predominan t species and the phytoplankton structure. The authors considered silicate a limit ing factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and up take by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrins ic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant-nutrient concentrations but low phytoplankton biomass in some waters is reasonably explained in this paper.  相似文献   

20.
研究了福建沿海自晚更新世以来控制主要断陷盆地、平原和海湾的断裂活动性状,认为这些构造在所讨论的时段内具有强烈的张性活动,而发生于区内的地震与这些构造的近期张性活动有关。  相似文献   

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