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41.
广东省水库富营养化评价   总被引:13,自引:2,他引:11  
广东省水库水环境质量调查评价结果表明:广东省水库水质总体较好,但不同程度地发生了富营养化;在汛期,被 评价的132座水库中中营养型水库111座,中富营养型水库12座,富营养化水库2座;非汛期,中营养型水库111座,中富 营养型水库11座,富营养化水库1座.造成水库富营养化的主要原因是面污染的日益加剧、城市污水排放量的激增、水土 流失造成水库泥沙淤积严重、水库蓄水量减少等.水库的富营养化影响了其使用功能.为恢复富营养水库的使用功能,其 对策主要是减少面污染物排放量、提高污水处理率、加强水土流失的治理、清除淤泥等.  相似文献   
42.
临邑凹陷辉绿岩中石油包裹体形成条件与油气成藏研究   总被引:5,自引:2,他引:3  
在临邑凹陷商河地区,商52井浅成辉绿岩侵入体中发现大量黄色和黄绿色荧光的石油包裹体,主要赋存在长石解理、裂隙中,多数为十分细小的纯液态的石油包裹体。测得其中部分粒径较大的石油包裹体的均一温度th=79~82℃,表明这些石油包裹体是辉绿岩体侵入Es3地层冷却以后受地层水作用在发生的多种蚀变反应的过程中长石的节理、裂隙愈合带封存了渗入的烃类物质而形成的。石油包裹体的PVTsim模拟计算结果表明,捕获温度ttr为88.6~92.1℃,捕获压力ptr为22.2~23.0MPa。与本区沙三段地层砂岩储层中石油包裹体捕获温度、捕获压力的对比结果表明两类石油包裹体的成藏条件基本相似。本区玄武岩-辉绿岩中的油气藏,实际上是特殊岩性储层的油气藏,其勘探前景主要受临邑凹陷多孔隙、裂隙的火成岩分布规模与沟通烃源岩的断裂和各种圈闭的控制。  相似文献   
43.
西江河口段溶解无机碳稳定同位素组成的时空变化   总被引:3,自引:1,他引:2  
For researching the spatio-temporal variation of the stable isotopic composition of the riverine dissolved inorganic carbon(DIC),we had carried out a survey throughout the hydrologic year during which theδ^13CDIC of the surface water and its physicochemical parameter were examined along the Xijiang River Inner Estuarine waterway from September 2006 to June 2007.There was a striking seasonal variation on the averageδ^13CDIC,as the averageδ^13CDIC in summer(-13.91‰)or autumn(-13.09‰)was much less than those in spring(-11.71‰)or winter(-12.26‰).The riverineδ13C DIC was controlled by decomposed condition of the riverine organic matter linking the seasonal variation of the physicochemical parameter in the surface water according to the correlation analysis which indicated notable relations betweenδ^13CDIC and water temperature(p=0.000;r=-0.569)or betweenδ^13CDIC and oxide-reduction potential(p=0.000;r=0.646).The striking positive correlation between δ^13CDIC and the sampling distance happened in the summer rainy season,while striking negative correlation happened in the spring dry season,indicating that river-sea interaction influenced water physicochemical parameters and controlled the riverine DIC property in the survey waterway.In view of the riverineδ^13CDIC decreasing for the decomposition of the terrestrial organic matter in the rainy season in summer and increasing for the briny invaded zone extending in the spring dry season along the waterway from the Makou gauging station to the Modaomen outlet,theδ^13CDIC spatio-temporal variation was closely related to the geographical environment of the Xijiang drainage basin.  相似文献   
44.
阳郭黄土剖面有机组分变化的周期性与古气候变迁因素   总被引:1,自引:0,他引:1  
刘友梅  贾蓉芬 《沉积学报》1996,14(A00):136-142
渭南阳郭黄土剖面是迄今发现的15万年以来较完整的剖面之一,作者对出阳郭剖面中的有机质指标进行了概率分布与谱分析计算,得出它们的概率分布类型及四个稳定的周期:67.1Ka,33.5Ka,25.2Ka和18.3Ka。这四个周期与洛川黄土剖面中元素组分变化的短周期基本一致。  相似文献   
45.
选择西峰和段家坡两个黄土剖面,对磁化率变化显著的L6-S5-L5层段,通过对样品中的趋磁细菌(MB)用相同的培养基富集及生长培养,初步定量模拟了MB和磁小体(MSs)对黄土-古土壤序列磁化率的贡献。富集培养MB后,段家坡剖面样品磁化率表现出不同程度的增高,最大达116.4%(DS5-1)。以古土壤样品XS5-1、DS5-1为介质生长培养MB,DS5-1磁化率的增长与接种的菌液量呈近似线性关系。此外,生长培养后古土壤样品频率磁化率与FeO/Fe2O3比值呈现出相似的变化趋势,证实了磁小体的形成。由此表明:1)MB和MSs是影响黄土剖面磁化率的因素之一,受气候和地质环境等因素的影响,不同地区黄土剖面MB的生长和MSs的形成存在差异,因此对磁化率的贡献也不尽相同;2)MSs是黄土-古土壤序列中超细粒磁性物质的组成部分。当气候环境比较适宜MSs形成及保存时,MSs在黄土剖面中超细粒(≤50nm)磁性组分中比重会相应增高,对磁化率和频率磁化率的影响也更为突出。  相似文献   
46.
我国西沙群岛第四纪生物沉积物及成岛时期的探讨   总被引:2,自引:0,他引:2  
Bioclastic sediments in the Xisha archipelago were formed during the period from late Pleisloeene to Πolocene. Except for loose coral shell sand, they can be dividcd,according to petrological features, into coral reef limestone, phosphate-cemented foraminifera (or red aglae and Eehinodermate, etc.), calcarenite or calcirudite. All of them have been subjected to raring degrees of deuterogene alterations such as phosphatization, calcitization as well as dissolution and filling. The age of formation of the Xisha archipelago, i.e., the time it finally emerged from under the sea may be dealt with as: (1) Sand bars. (1.5-3.0 meters above sea level) took shape about 2000--2500 years ago; (2) Coral reefs (3--5 meters above sea level, with the exception of rock islands) formed 400-5000 years ago, which is in agreement with the high sea level stage in the post-glacial period; (3) Rock islands(about 15 meters above sea level) formed at late Pleistocene or earlier, which can probably be correlated with the high sea level period some 80000--125000 years ago.  相似文献   
47.
碳酸岩生油岩中沥青变质程度和沥青热变质实验   总被引:4,自引:0,他引:4  
Natural asphalts from carbonate rocks in South China have been studied by using microscopy, X-ray diffraction, ESR and C^-, H^- analysis and subjeeted to thermal alteration experiments under 250℃/1000 atm--500℃/1000atm. It is shown that asphalt and vitriolic behave differently under conditions of thermal alteration. In compariseu with vitriuite, asphalt is of higher reflectivity, more apparemt anisotropy,lower values of d002 and H/C ratio above 350℃. The mierostructure and charaeter of protoasphalt disseminated in carbonate rocks and diagenetic asphalt reflect the thermal history and the maximum paleotemperature to which they haxt been subjected. Reflectivity, H/C ratio, d002 etc. of the asphalts in carbonate rocks may be used as indicators for the extent of maturity of earbenate source rocks. Based on measurements carried on asphalts of pertinent occurrences. R^0=1.65.H/C=0.75, d002=3.53 A are suggested as creteria for the distinction between Oil and natural gas field in carbonate terrains in China.  相似文献   
48.
碳酸盐岩生油岩的有机地球化学、岩石学特征   总被引:13,自引:1,他引:13  
Features of oil-generating carbonate rocks are studied in terms of petrology and organic geochemistry of fluorescent materials in rocks. It is postulated by the authors that the organic carbon content in oil-generatlng carbonate rocks is necessarily lower than that in shales, and the possible cause of this observation is discussed. The quality of oil-ganerating carbonate rocks may be judged by aromatic structure index,amino acid, pigment index, and DTA data on organic matter. However, the application of presently available organic geochemical criteria to non-oil-generating reservoir rocks may always give misleading results. To circumvent this difficulty, it is necessary first to make distinction between primary and secondary organic matter by cxamining the fluorescent materials under a fluorescence microscope. Measurementof radical content of the organic substances and DTA are useful techniques to determine the degree of maturation. The maturation of organic substances proceeds at a lower rate in carbonate rocks than in shales. It is likely, therefore, that some older carbonate strata can also be promising areas for petroleum exploration. Oil-generating carbonate rocks consist mainly of mierite limestones rich in organic matter and are thought to be formed under low-encrgy environment. Consequently, petrological(especially mierolithofacies) studies are very important in evaluating carbonate source rocks.  相似文献   
49.
一种分离富集中国黄土中微米级磁性物质的方法   总被引:1,自引:1,他引:1  
微米级磁性矿物在黄土—古土壤序列中含量不足1%,为了满足多种测试的需要,要尽可能地富集磁性矿物。介绍一种富集方法,即程序地采用浸泡—搅拌(转速为5900r/min)—湿法磁选(磁场梯度范围为0.8—2.5T)—重液分选(d≥2.5)—干法磁选(激磁电流在1—2A之间)的方法,从西峰和段家坡第五层古土壤(分别简称为XS和DS)的上浮物和沉砂中富集出6个不同磁性的矿物组分。经磁化率(MS—2)、磁滞回线(MICROMag2900)测定、高倍显微镜(MPV—3)及扫描电镜(S—3500N)观测,矿物的分散度与磁性分选良好,精选的强磁性组分(XS—4J和DS—4J)中磁性矿物含量约占该组分的30%,富集的磁性矿物种类多,包括含铁粘土、碎屑状磁性矿物和自生磁性矿物,磁选出的矿物代表性强并能满足多项分析测试的需要。湿法磁选(程序3)是流程中操作最复杂的一步,根据XS样的实测结果,这一步磁选的回收率为87.2%。  相似文献   
50.
应用碳同位素动力学方法探讨阿克 1气藏天然气的来源   总被引:5,自引:1,他引:5  
阿克 1气藏是塔西南前陆区喀什凹陷油气勘探上获得重大突破的工业性气藏.采用金管封闭体系热模拟实验和 GC-IRMS碳同位素测定,结合运用 GOR-ISOTOPE KINETICS专用软件,推导出了塔西南前陆区烃源岩 (煤和泥岩 )热解生成甲烷的碳同位素动力学参数.该区侏罗系煤、侏罗系泥岩和二叠系泥岩的平均活化能分别为 225.86 kJ/mol、 194.03 kJ/mol和 223.45 kJ/mol,甲烷 (12CH4)的指前因子各为 1.00× 1014 s-1、 1.00× 1013 s-1、 1.00× 1014 s-1.在此基础上,利用碳同位素动力学计算结果,并结合地质背景,进一步探讨了阿克 1气藏天然气的来源,为天然气定量评价提供了新思路.阿克 1气藏天然气为烃源岩过成熟阶段的烃产物,属于混源气,主要捕获了 Ro 为 2.0%~ 3.6%阶段的天然气;其气源区包括喀什凹陷中心和阿克 1井推覆体下盘,主力气源岩是石炭系烃源岩.  相似文献   
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