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1.
强弱风浪扰动下太湖的营养盐垂向分布特征   总被引:24,自引:4,他引:24       下载免费PDF全文
在一次风速12m/s的强风浪过程中及在连续多天弱风浪之后,对太湖梅梁湾一浅水区营养盐、悬浮物等的垂向分布进行了观测和分析。结果表明,在水底沉积物约20cm的情况下,强风浪期间与弱风浪期间相比,湖水中悬浮物浓度提高了10倍,总磷浓度提高了3 6倍。而强风浪期间与弱风浪期间的水体溶解性总磷(DTP)、溶解性活性磷(SRP)的浓度无显著差异。说明尽管强风浪过程引起沉积物大量悬浮,水体悬浮颗粒态营养盐显著增高,但是由于悬浮过程营养盐释放与沉降机制作用十分复杂,活性营养盐的浓度未必能提高。无论强风浪还是弱风浪期间,水体的表层至水土界面上50cm层的悬浮物浓度、营养盐浓度没有明显的分层现象,但明显低于水土界面上50cm内的悬浮物浓度和总磷浓度。无论是强风浪期间还是弱风浪期间,表层到底层水体SRP浓度无显著差异。  相似文献   

2.
密云水库总磷的富营养化分析与预测   总被引:5,自引:3,他引:5  
根据1991~1999年密云水库总磷质量浓度的实测数据,得到了9年平均总磷表面负荷Lp,建立总磷的预测模型。应用预测模型,预测了2008年密云水库的富营养化状态,当年平均总磷表面负荷分别为(1~2.1)Lp时,密云水库的水质可这中营养状态;负荷为(1.99~2.15)Lp时,水质可达中—富营养状态;负荷大于2.15Lp时,水质可这富营养状态。由此得出,当水库总磷表面负荷达到一定峰值后,水库水质将在总磷表面负荷的一个很小的变化范围内,迅速进入中一富营养厦富营养状态。  相似文献   

3.
地表基质是地球表层物质与能量循环的主要载体,地表基质调查是一项创新性工作,明确地表基质调查分层及分层测试指标是开展地表基质调查的基础。本文基于地表基质调查的内涵和目标定位,深入分析了多目标区域地球化学调查、全国第三次土壤普查和全国农用地土壤污染详查等调查深度和测试指标;利用近三年自然资源综合调查指挥中心在吉林省梨树县、辽宁省丹东市、黑龙江省哈尔滨市三个地表基质调查试点项目实测数据,运用变动系数法分析了不同地区地表基质层的地球化学元素垂向变化特征,结合表生地质作用(风化为主)最大深度、地表植被根系最大深度、浅层地下水位波动下限、基岩顶面深度等因素,将地表基质在垂向上大致分为三层:表层(0~2m)、中层(2~10m)和深层(10~20m),基岩埋深浅于20m则以揭露到基岩为准;表层(0~2m),称为生产层,包括支撑农业生产的耕作层,主要服务国家粮食安全,以收集资料为主;中层(2~10m),称为生态层,主要支撑植被生长和群落演替,服务国土空间开发保护与格局优化,是地表基质调查的重点;深层(10~20m),称为沉积层,主要研究地表基质从基岩—深层—中层—表层演替规律和特征,以部署少量工程控制为...  相似文献   

4.
柴达木盆地新生界湖盆咸化特征及沉积响应   总被引:1,自引:1,他引:0       下载免费PDF全文
柴达木盆地新生界发育咸化湖盆沉积,但是对于湖盆的咸化程度一直没有详细论述,其沉积响应特征亦不清楚。文中利用系统测试得到的硼元素及黏土矿物资料来开展古水体盐度恢复,结果表明:(1)柴达木盆地新生界为咸化湖盆沉积,最高盐度大于20‰;(2)不同盐度地区的沉积响应特征不同,其中陆源碎屑物供给区古盐度小于12‰,滨浅湖区古盐度在10‰~18‰之间,半深湖区古盐度大于18‰。在中高咸化湖盆水介质的控制作用下,沉积物分布表现为单层厚度小(一般为1~3m)、砂/泥岩互层频繁、三角洲沉积相带分布较窄、细粒沉积物分布范围较广、发育特有湖相碳酸盐岩和膏盐岩及与陆源细碎屑呈混积等特征。  相似文献   

5.
密云水库水体的地球化学特征   总被引:16,自引:3,他引:16       下载免费PDF全文
研究了密云水库在2001年一个完整水文年的水体地球化学特征。结果表明:该水库水质清澈,透明度平均为2.54m,pH平均值为8.81;水中溶解氧丰富,平均为6.98mg/L;有机物耗氧量平均为2.07mg/L;平均矿化度为246.97mg/L,水型属重碳酸盐类、钙组Ⅱ型水(CⅡ^Ca)。水体中的主要生物营养元素氮含量较高,总氮平均为0.96mg/L,磷含量较低,总磷平均为0.025mg/L。水库氮、磷浓度比为38.4:1,显示磷为该水体生物生产力的主要限制性营养元素。水体中重金属铬、镍的含量变化特征反映了原始老变质基岩成分的有关特点;而重金属铁、杨、铅、汞、砷的含量变化规律则显示密云水库水体已受到上游流域工业活动的影响。  相似文献   

6.
总磷是长江流域水环境污染的首要超标因子,岷江作为长江上游流量最大的支流,总磷污染严重,对长江总磷污染贡献较大。为了解岷江流域总磷污染,采用排污系数法,计算得到2016年岷江流域污染源总磷入河量为1 154 t,以农村生活污染负荷占比最高(51.3%),其次为城镇生活源(28.7%)、农业非点源(8.24%)、工业源(9.57%)、畜禽养殖源(1.21%),城市径流源(0.99%)最低;在空间上岷江流域总磷污染负荷呈中游(64.2%)>下游(32.6%)>上游(3.1%)的特点,与岷江干流总磷浓度变化趋势相符,其中成都市总磷污染负荷最高(51.2%),与区域人口密度高、生产和生活活动密集有关。结合资料收集和现场调查,岷江流域总磷污染成因主要包括农村生活污染治理缺口较大、城镇生活污染处理基础设施建设不足、工业企业密布、部分支流总磷污染严重、水污染治理导向不全面。针对岷江总磷污染负荷分布特征及成因,提出“上游保护优质水体、中游治理重污染水体、下游恢复不达标水体”的分区污染防治对策,统筹流域监管体制机制,强化岷江流域水环境保护和治理。  相似文献   

7.
为研究龙滩水库枯水期溶解态氮、磷营养元素的空间分布特征,在龙滩水库枯水期(2017年1月份)进行分层采样,现场测定水体理化性质及实验室分析水中营养盐浓度。结果表明:龙滩水库水温出现明显垂直分层:0~10m为温跃层;10~60m为混合层;60m以下为底温层;pH值为7.63~7.92,水体呈弱碱性。溶解无机氮(DIN)平均浓度为4.75mg/L。水体溶解性氨氮、硝态氮、亚硝态氮平均值为0.07mg/L、2.62mg/L、2.05mg/L,分别占DIN的1.6%、55.2%、43.2%,硝态氮、亚硝态氮是组成龙滩水库溶解无机氮的主要成分。磷酸盐平均浓度为0.04mg/L。参照潜在性富营养化评价标准,N/P(质量比)比值为73.84,说明龙滩水库枯水期属于磷限制潜在性富营养状态,营养状态空间分布特征:坝前水体双江口红水河镇小马场。  相似文献   

8.
密云水库沉积物中磷的形态和分布特征   总被引:26,自引:3,他引:26       下载免费PDF全文
采用连续提取化学分析技术,对密云水库的柱状沉积物和表层沉积物样品进行了磷形态的提取分析,研究了各种形态磷在表层及垂立方向上的分布特征。分析结果表明,密云水库沉积物中以无机磷为主,有机磷次之,无机磷占总磷的76.88%。95.09%。沉积物中总磷及其不同形态无机磷在垂直方向上的分布变化规律为:总磷、可溶态磷含量随深度增加而降低,Ca—P合量随深度增加而增加,Al—P和闭蓄态磷变化幅度不大,Fe—P、有机磷的垂直方向变化情况较复杂。潮、白河流域总磷与各形态磷在表层及垂直方向上的分布差异在一定程度上反映出近年来水库所受上游流域工业活动和人为污染的影响情况。  相似文献   

9.
黔西北玄武岩风化壳中的稀土矿是一个分布广泛、稀土含量较高的新类型稀土矿。本文主要通过岩相学、矿物学和地球化学的方法,系统研究了该稀土矿层的岩石组构、矿物组合及地球化学特征,探讨了该地区稀土迁移富集机理。结果显示该风化壳稀土矿层厚度大(单层厚度0.1~0.5 m,总厚度约5~15 m)。矿石中主要矿物为高岭石(60%~80%),次要矿物为蒙脱石(2%~8%)、赤铁矿(5%~20%)。稀土总量较高(144~2288×10-6),具轻稀土富集特征,并且稀土含量高的样品均为高岭石粘土岩。稀土配分模式图中显示明显负铕异常(0.22~0.85),铈异常变化较大(0.86~1.63)。综合分析认为玄武岩风化壳中的稀土元素的富集和高岭石的含量密切相关,稀土元素可能在偏还原的环境中被高岭石颗粒吸附。  相似文献   

10.
太湖五里湖表层沉积物中不同形态磷的分布特征   总被引:23,自引:0,他引:23  
利用连续提取法(SEDEX)详细调查了太湖五里湖表层沉积物中不同形态磷的组成和分布特征。结果显示:其中磷的含量较高,受人为污染输入的影响较大,并且已经有了一定的释放。总磷的变化范围为2.05~4.05mg/g。平均约为2.80mg/g。总磷主要由无机磷组成(70%~90%),大多数无机磷为CDB溶液提取的铁结合态磷(75%~85%)。CDB溶液的n(Fe)/n(P)都较小(2.0~5.3)。说明CDB溶液提取的铁主要是以无定形态存在的,并且铁与磷酸盐之间的吸附可能已经达到了平衡状态。除底部个别样品以外。多数样品n(Gorg)/n(Norg)较小(8.8~10.6),所有样品的n(Gorg)/n(Porg)都较大(135~320),表明沉积物在早期成岩作用过程中,湖泊内源自生有机质降解时有机磷优先释放。无机磷,特别是铁结合态磷,在氧化还原条件变化的情况下。能够通过沉积物一水体界面被再次释放到水体中去,这可能对湖泊的水体质量和营养状况有一定的影响。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

15.
PALEONTOLOGY     
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)  相似文献   

16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)  相似文献   

17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)  相似文献   

18.
PETROLOGY     
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,  相似文献   

19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of  相似文献   

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