上海潜水水文地质特征及应用研究前景的初步探讨

潜水是上海地区浅层地下水资源。赋存在第四系全新统地层之中。埋深在1～40米不等。按其成因类型可分为全新世晚期(Q_4~3)河口——滨海相潜水,全新世晚期滨海相潜水,全新世早期(Q_4~1)河口——滨海相微承压——潜水。皆属孔隙潜水,分布广泛,富水性分为三级:100～500立方米/日;10～100立方米/日;<10立方米/日。渗透系数(K)在0.01～4.00米/日,一般<1.0米/日。导水系数(T)为0.02～26.7米~2/日,其中三分之二小于     

渤海菜州湾第四纪晚期以来微体化石组合特征和沉积环境演化

对渤海莱州湾南岸央子镇YZ1钻孔取微体古生物样品18个，通过分析鉴定和地层对比，以及对微体古生物化石进行属种、丰度和分异度分析，共划分出4个化石组合层段。根据化石组合特征分析认为：第Ⅰ、第Ⅱ微体化石组合为全新世海侵的产物。第Ⅰ组合代表了海进序列，沉积环境为潮上带—潮间带；第Ⅱ组合为海退序列，沉积环境为潮间带—潮下带。第Ⅲ、第Ⅳ组合分别是晚更新世2次海侵的产物。第Ⅲ组合为晚更新世末期海侵的产物，海侵规模较大，沉积环境为滨海潮坪—潮间带；第Ⅳ组合海侵规模较小，陆相因素增大，沉积环境为河口—滨岸带或者为海陆交互相。     

从微体化石探讨浙南沿海全新世地层及沉积环境

浙南沿海地区晚更新世顶部(Q_3~3)的陆相地层,岩性以灰黄色粘土质粉砂、粉细砂为主,未见到微体化石,仅含较多的植物碎屑。全新世地层存在两个微体古生物化石层,第二化石层属全新世早期～中期(Q_4~(1 2))的地层。岩性以青灰色粘土为主,微体化石很丰富,为浅海相沉积。第一化石层则属全新世晚期(Q_4~3)地层。岩性以黄灰、黄褐色粉砂质粘土为主,微体化石比较丰富,为海陆过渡相至滨海相沉积。第二化石层比第一化石层海侵程度强,而同一化石层相比,南部又以北部海相性大。     

杭州湾晚第四纪沉积与古环境演变

通过对杭州湾第四系钻孔的年代地层学、沉积学、古环境学等多学科综合分析,认为XZK169孔全新世沉积始于孔深17.35m处(年代约为10～9kaBP),其下至孔深86.40m沉积属晚更新世。整个沉积层中可分出3个海进—海退旋回晚更新世早期以陆相沉积为主,出现河湖相—滨海湖泊相—河湖相沉积,气候为温凉干燥—温暖湿润—温凉干燥;晚更新世中晚期出现河湖相—潮滩湖相—浅海相—河口湾相沉积,气候为温凉干燥—寒冷干燥—温凉—暖热湿润—温热湿润;经历了末次冰期侵蚀后,全新世出现浅海相—河口湾相沉积,气候以暖热湿润—温暖湿润为主。约在5kaBP,杭州湾与长江口分离。     

废黄河三角洲典型钻孔XJ01全新世地层与微体古生物记录

钻孔XJ01位于废黄河三角洲滨淮镇附近,钻孔中上更新统顶部与全新统有4个14C测年数据控制,该孔全新统岩性特征自下而上为潮间带含贝壳砾质砂层、浅海相淤泥质黏土层、三角洲前缘相深灰色粉砂、三角洲平原相黏土质粉砂及粉砂质黏土。全新统微体古生物分析结果详细地反映了废黄河三角洲典型区域各时期的沉积环境,其中,全新统下部见大量的有孔虫与海相介形虫,中部微体古生物略少,上部地层中海相介形虫增多。整个全新世微体生物组合揭示了一个河口变化的水动力控制沉积环境。     

河北白洋淀全新统沉积特征与地层划分

通过对河北白洋淀老河头剖面全新世沉积物岩性特征、地层层序、粒度组成及微体古生物组合等进行综合研究,重建了白洋淀全新世以来的环境演变过程。全新世以来白洋淀沉积特征所反映的气候环境特征表现为早期开始出现湖沼相沉积,气候寒冷偏湿;中期湖泊沉积发育,气候温暖湿润;晚期湖泊退缩,以河流-沼泽相沉积为主,气候向凉干转变。综合沉积特征、环境演变阶段与加速器质谱(AMS)14C测年资料对白洋淀全新统沉积序列进行系统分析,并将全新统划分为三段:下全新统(11000—8500 a)以灰黄色粉砂质粘土、粉砂为主,夹黑色粘土,冲积-湖沼相沉积发育;中全新统(8500—3200 a)为灰黑色粘土夹粘土质粉砂,湖沼相沉积发育;上全新统(3200 a~)以黄色、褐黄色粉细砂、粘土质粉砂为主,冲积-沼泽相沉积发育。白洋淀全新统中段含有黑色粘土沉积和大量微体与腹足、双壳类等古生物化石,为华北地区全新世地层的划分及区域对比提供了依据。     

滦河口北部七里海地区中晚全新世沉积演化过程

滦河口北部七里海地区全新世演化过程是划分滦河三角洲范围的依据,也是认识陆海相互作用的有益补充.通过对七里海地区6个钻孔进行详细的沉积学、微体古生物研究和年代测定,分析了中晚全新世以来的沉积环境演化过程.滦河口北部七里海地区发育中晚全新世冲积扇-湖相三角洲、晚全新世砂坝-潟湖和海相三角洲及近现代砂坝-潟湖地貌沉积体系.6...     

兰州-民和盆地下白垩统河口群沉积序列及沉积相研究

兰州—民和盆地下白垩统河口群是一套厚度巨大的陆相碎屑岩沉积，根据岩性组合和沉积旋回，自下而上将河口群划分为8个非正式的组级单位。通过对河口群基本层序的分析和沉积序列及沉积相的研究，可以识别出冲积扇相、三角洲相和滨浅湖相3类相环境，细分为13种微相。沉积相的演变从整体上反映了整个盆地的演化过程。河口群的沉积环境由冲积扇相→三角洲相→滨浅湖相→三角洲平原相演变，形成了一个完整的序列，反映了盆地从开裂→扩张→萎缩→消亡的不同发展阶段。     

渤海湾西南岸古黄河三角洲全新世地层层序和演化过程

对渤海湾西南岸6个钻透全新统的钻孔进行了详细的沉积学研究和年代测定,利用160个粒度和94个微体古生物样品共同确定沉积相,并利用22个泥炭的常规14C年代,依据层序地层学原理划分了全新世地层层序,恢复了演化过程.渤海湾西南岸全新世黄河三角洲地层主要包括海侵层序、高海面层序和加积层序,海侵层序包括滨海沼泽、滨海砂坝和下切河谷,时代为8.5ka B.P.至全新世底界;高海面层序下段西部为滨海湖沼和积水洼地等滨海相,东部为潮成沙脊、前三角洲和潮下带等海相,时代为7.6～8.5kaB.P.;高海面层序上段西部为河间洼地、沼泽和分支河道等泛滥平原相,东部为河口砂坝、潮间带和潮成沙脊,时代为3.0～7.1ka B.P.;加积层序主要为分支河道、决口扇和河间洼地等沉积相,时代为3.0ka B.P.至今.渤海湾西南岸在9.0ka B.P.开始受海水影响,形成滨海湖沼;7.1～7.6ka B.P.达到最大海侵,位于旧城和盐山之间;海岸线于5.6ka B.P.时位于黄骅苗庄贝壳堤一带,于3.0ka B.P.时位于YS4和NP3孔之间,于2.0ka B.P.时形成现今岸线.古黄河于8.5～9.0ka B.P.时经YS3孔和NP1孔入海;于7.6～8.5ka B.P.时经YS4和NP3孔入海,于1.9～2.6kaB.P.时经YS7和NP1孔入海.5.6～7.1ka B.P.时期,研究区为当时古黄河三角洲的侧翼,形成河口砂坝,废弃之后形成潮成沙脊和苗庄贝壳堤.1.9ka B.P.至今,黄河在研究区外侧入海.     

苏州澄湖SC1孔晚更新世晚期以来的古环境演变研究

通过对苏州澄湖SC1孔沉积物的粒度、磁化率、孢粉和有孔虫等的实验分析,并结合沉积物的岩性构造特征以及AMS 14C测年数据,探讨了晚更新世晚期以来苏州澄湖地区的气候波动特征以及海侵、海退沉积巡回序列。研究发现该区域气候与世界气候波动性一致,具有温暖湿润-冷而略干-温暖湿润-暖热潮湿-温凉略干-温暖湿润的波动变化特征;晚更新世晚期以来具有两个海相沉积地层,一为晚更新世晚期海侵(约为34 kaBP),另一为全新世中期海侵(（6 955±50）aBP);整个剖面缺失硬粘土层,与之对应的则是两海相地层之间的泥砂互层;沉积环境经历了晚更新世晚期海侵期河床、河漫滩相-末次冰期干冷期河流湖沼相-全新世早期河口湾亚相-全新世中期滨浅海相-全新世晚期淡水湖沼相的演变过程。     

长江河口及其水下三角洲晚第四纪地层和环境变迁

笔者系统地研究了长江河口地区的晚第四纪地层。长江三角洲前缘区晚第四纪地层可划分为上更新统上段中部、全新统下部、全新统中部和全新统上部。上更新统顶部地层缺失。前三角洲区晚第四纪地层齐全，无缺失。武木冰期晚期，现今的长江河口和大陆架均出露成陆，古长江在大陆架外缘入海。１５０００ａＢ．Ｐ，海面上升，海水逐渐向大陆架上部侵入；１２０００—１００００ａＢ．Ｐ，海水沿谷地侵入；６０００ａＢ．Ｐ，长江人海口在扬州、镇江附近。随着人类活动的增强，长江流域水土流失加剧，人海河口不断外移，并以南岸边滩推展，北岸沙岛并岸的形式使河口不断束狭，逐渐形成现今长江口三级分汉四口入海的态势。     

江苏南通市四甲镇全新世以来有孔虫动物群的发现及其地质意义

对江苏省南通市四甲镇CSJA6钻孔上部近43m的沉积物岩心进行了沉积学、年代学研究和有孔虫鉴定及组合划分,发现41属77种(含8个未定种)有孔虫。根据有孔虫动物群的垂直分布特征与AMS14C年龄,初步建立了时间被部分标定的全新世有孔虫化石组合,自上而下为Ammonia beccarii vars.-Cribrononion subincertum Asano组合、Ammonia beccarii vars.-Globigerinira glutinata组合和Ammonia beccarii vars.-Elphidium magellanicum组合。组合2、3带的时间界线约为8.1ka cal BP,组合3带的下界至少是10ka cal BP。这3个组合带的特征与以珠海、上海地区为代表的中国东部沿海平原全新世有孔虫组合相似。若将前人全新世海侵的14C年龄做进一步的校正,并结合本文钻孔研究成果可初步推测,在8.5~8ka cal BP时长江三角洲地区达到最大海侵,形成以镇江、扬州为顶点的长江巨大河口湾。     

江苏江都市大桥镇晚更新世晚期—全新世有孔虫动物群的发现及其地质意义

在江苏省江都市ZKA4钻孔孔深4.0～42.6 m岩心段中发现有孔虫化石,鉴定识别出有孔虫38属56种,其中9个未定种,根据有孔虫动物群在钻孔剖面上的分布规律,建立了 3个有孔虫化石组合,自上而下为:Ammonia beccarii Linne)vars.-Orbulina universa组合,Ammonia bec...     

Recent foraminifers from the inner shelf of the central West Coast,India: A reappraisal using factor analysis

Setty and Nigam (1980) had described 72 species of benthonic foraminifers from 25 inner shelf stations off central West Coast of India and the results showed somewhat patchy and anamolous distributions. This paper presents the results ofQ-mode factor analysis, which was applied to reduce the number of variables into assemblages. The analysis reveals 4 important foraminiferal assemblages.Ammonia beccarii—Ammonia annectens assemblage,Nonion boueanum—Florilus scaphum assemblage.Trochammina inflata assemblage andBulimina exilis assemblage. They can be related to freshwater run-off and organic matter contents of the sediment.     

广西铁山港海区表层沉积物与沉积相

本文论述了铁山港海区表层沉积物的沉积类型、碎屑重矿物、贝壳类,有孔虫和介形虫群的分布特征。根据岩芯中微体化石群,岩性特征和14C测定年代数据,确定沉积相及其年代,并讨论沉积物来源和运移。     

中国东部海岸带现代有孔虫碳同位素及其古环境意义

在第四纪海陆过渡相环境研究中,有没有能够确定古盐度的定量标志?本文作者针对中国东部第四纪海陆过渡相地层中常见的两种有孔虫Ammonia beccarii(Linne)vars.和Protelphidium glabrum(Ho, Hu et K. Wang)进行现代样品的碳同位素分析。在现代样品研究的基础上,确定了碳同位素与盐度存在线性关系,运用这一结果于第四纪几个钻孔样,并综合有孔虫化石群其他特征,推导古环境特点。     

Micropaleontological record of Holocene estuarine stages in the Bahía Blanca estuary,Argentina

Holocene paleoenvironmental changes have been interpreted on the basis of benthic foraminifera and calcareous nannofossils recovered in samples from Napostá Grande Stream, Bahía Blanca estuary, southern Buenos Aires Province. Samples are fine sands and clay sediments from a Holocene outcrop and were studied with quantitative techniques. The benthic foraminiferal assemblage is dominated by Ammonia parkinsoniana, Ammonia tepida, Bolivina pseudoplicata, Bolivina striatula, Bolivina sp., Buccella peruviana, and Elphidium spp. The calcareous nannofossil assemblage recovered is a typical cold-water association, dominated by Calcidiscus leptoporus, Coccolithus pelagicus, Emiliana huxleyi and Gephyrocapsa oceanica. A dendrogram classification by cluster analysis was made for each microfossil group. The results of these analyses were coincident, showing a liaison between changes in the assemblages of benthic foraminifera and calcareous nannofossils. Those results, jointly with the sedimentological information, lead to the identification of three different paleoenvironments along the Napostá N1 site. The lower part of the succession represents an estuarine environment with larger marine connection. The middle part represents a gradual passage to a more restricted estuarine environment, and the upper part represents the establishment of the modern continental fresh-water environment.     

Holocene Foraminifera as Indicators of Relative Estuarine–Lagoonal and Oceanic Influences in Estuarine Sediments of the River Murray, South Australia: Volume 53, Number 3 (2000), pages 378–391

In southeastern South Australia, the River Murray debouches through a coastal barrier separating euryhaline estuarine-lagoonal waters from the Southern Ocean. Depending upon the relative freshwater outflow of the river and ingress of the ocean, water salinity varies greatly within the lower estuary. Ammonia beccarii and Elphidium articulatum are euryhaline species of foraminifera that characterize the estuary and back-barrier Coorong Lagoon. The inner-shelf marine environment hosts an assemblage in which Discorbis dimidiatus, E. crispum, E. macelliforme, and various cibicidid species predominate. In cored sediments recovered from the shallow lower estuary, the relative abundance of A. beccarii + E. articulatum was compared with that of D. dimidiatus + E. crispum + E. macelliforme + other species. These data, and AMS radiocarbon ages determined for foraminifera and ostracods, provide evidence of a change from maximum oceanic influence (5255 ± 60 yr B.P.) to maximum estuarine influence (3605 ± 70 yr B.P.). Over this same time interval, sea level fell relatively by about 2 m. However, the event was also contemporaneous with falling water levels in several Victorian lakes, and it is thus attributed to onset of climatic aridity. Reduced precipitation in the River Murray catchment and reduced freshwater outflow enhanced development of the flood-tide delta and constriction of the mouth.     

Trophic structure of macrobenthic communities in the Calcasieu estuary,Louisiana

Trophic groups were used to investigate broad patterns and predict species interactions of macrobenthic assemblages in Calcasieu Estuary, Louisiana. Macrobenthic assemblages of the estuary were numerically dominated by deposit-feeding species. Surface-deposit feeders were the most abundant macrobenthos of the upper estuary, subsurface-deposit feeders dominated the lower estuary, and a trophically well-mixed assemblage inhabited the middle estuary. There were periodic shifts in species dominance within each region, but the shifts were without temporal pattern and seldom led to changes in trophic structure of the region. The macrobenthic assemblages of the upper estuary were dominated by several early-colonizing species which switched feeding modes with changes in water flow, suggesting that disturbances in the upper estuary had a direct effect on macrobenthic communities. Disturbances also may have eliminated macrobenthic species before they could establish a well-mixed community. The presence of trophically mixed communities in the middle estuary probably was indicative of fewer disturbances there. The dominance by subsurface-deposit feeders in the lower estuary probably indicates that sedimentary food in Calcasieu Lake was seldom utilized at the sediment-water interface. Rather, most food became buried and was available only to subsurface-deposit feeders.     

Ostracod palaeoecology and environmental change in the Laptev and Kara seas (Siberian Arctic) during the last 18 000 years

Fossil ostracod assemblages were investigated in five AMS ¹⁴ C‐dated cores from various water depths of the Laptev and Kara seas ranging from the upper continental slope (270 m) to the present‐day shelf depth (40 m). Six fossil assemblages were distinguished. These represent the varying environmental conditions at the North Siberian continental margin since about 18 ka. In the cores from the shelf the ostracod assemblages reflect the gradual transition from an estuarine brackish‐water environment to modern marine conditions since 12.3 ka, as induced by the regional early Holocene transgression. The core from the upper continental slope dates back to c. 17.6 ka and contains assemblages that are absent in the shelf cores. The assemblage older than 10 ka stands out as a specific community dominated by relatively deep‐water Arctic and North Atlantic species that also contains euryhaline species. Such an assemblage provides evidence for past inflows of Atlantic‐derived waters from as early as c. 17.2 ka, probably facilitated by upwelling in coastal polynyas, and a considerable riverine freshwater influence with enhanced surface water stratification owing to the proximity of the palaeocoastline until early Holocene times. In all studied cores, relative increases in euryhaline species dominant in the inner‐shelf regions are recorded in the mid–late Holocene sediments (<7 ka), which otherwise already contain modern‐like ostracod assemblages with relatively deep‐water species. This observation suggests euryhaline species to be largely sea‐ice‐ and/or iceberg‐rafted and therefore may provide evidence for a climate cooling trend.