尤因塔盆地P. R.泉始新统油砂成藏条件及成藏模式

尤因塔盆地P. R.泉位于美国犹他州东北部,油砂资源丰富,油砂矿藏面积约650 km2,油砂储量约6. 76 × 108 t,储层为始新统绿河组湖泊三角洲相砂体。晚白垩世到古近纪拉拉米运动使盆地由海相转变为陆相盆地。古新世末-始新世,尤因塔湖在盆地内分布广泛,并沉积了两套巨厚的绿河组烃源岩。其中绿河组上部的中始新统烃源岩厚达150 m,有机质丰富,且仍处于低熟阶段,约30 Ma 以来,产生了大量的低熟油。P. R.泉油砂矿藏为斜坡降解型成藏模式,发育5 套广布的三角洲砂体,储层物性好。绿河组上部烃源岩生成的低熟油沿着深入烃源岩中的连续砂体经过长距离的运移,进入 P. R.泉绿河组三角洲的砂岩储层中,经过生物降解和水洗作用最终形成油砂矿藏。     

Heteroaromatic moieties in Green River oil shale kerogen

Investigation of the reaction of Green River oil shale kerogen with sodium borohydride in trifluoroacetic acid by infrared spectroscopy has shown the appearance of absorptions representative of lactams. These lactams can be shown to have possible precursors that are heteroaromatic in composition and as such could demonstrate the existence in Green River kerogen of aromatic nitrogen compounds.     

Elemental abundances in Green River oil shale

Spark-source mass spectrometric analysis of pyrolyzed Green River oil shale for trace element distribution showed enhanced concentrations for only lithium and beryllium. In general, trace elemental concentrations were found to be below anticipated crustal amounts. There appears to be no promise of any substantial accumulation of any trace elements within the organic matrix of Green River oil shale.     

长江江苏段生物体内重金属污染调查与评价

分别在3个不同水期采集了长江江苏段鱼类及底栖动物,分析了可食用部分中铅、汞等金属元素。分析结果表明,鱼及螺蛳受到不同程度的金属污染,底栖动物污染程度重于鱼类,主要污染元素为铅。     

The nature of straight-chain aliphatic structures in green river kerogen

Previous studies of the Green River kerogen only provide apparently contradictory conclusions about the size of the straight-chain aliphatic structures as well as the manner in which these structures form part of the kerogen matrix.The present investigation is an attempt to resolve this contradiction. A mild stepwise oxidation procedure was followed so that extensive degradation of kerogen-derived intermediates could be prevented. Products isolated from each oxidation step were analyzed by conventional GLC techniques, GC-MS, and proton-NMR measurements in order to ascertain the significance of the straight-chain aliphatic structures present in the Green River kerogen.The following results were obtained: (a) Green River kerogen contains a substantial portion (ca 2–4 carbons out of every 10) of straight-chain aliphatic structures which are longer than C₄, (b) the kerogen matrix forms a three-dimensional network of non-straight-chain clusters interconnected by long polymethylene cross-links, (c) the ‘core’, in comparison with the ‘periphery’ of the kerogen matrix, contains a greater proportion of straight-chain and branched aliphatic structures which are attached to the kerogen matrix at one terminus, (d) some of the straight-chain structures may exist as physically entrapped components in the kerogen matrix.     

The distribution of shallow water juvenile fishes in an urban estuary: The effects of manmade structures in the lower Hudson River

The objective of this study was to determine what effect, if any, large pile-supported platforms (piers) have on the habitat distribution and abundance of juvenile fishes. Trapping techniques were used in 1993 and 1994 under piers, in pile fields, and in open-water habitat types in shallow areas (<5 m) in the lower Hudson River estuary (40°44′N, 70°01′W). Nearly 1500 fishes, mostly juveniles, representing 24 species were collected in 1865 trap-days from May through October in the 2-yr study. The presence of relatively large numbers of young-of-the-year (YOY) fish during both years lends support to the idea that shallow areas in the lower Hudson River estuary currently function as nursery habitats for a variety of fishes. Two seasonal assemblages were apparent, but their composition varied somewhat between years.Microgadus tomcod andPseudopleuronectes americanus YOY dominated an early summer assemblage (May–July) while large numbers of YOYMorone saxatilis were collected as part of a late summer assemblage (August–September). The effects of habitat type on fish assemblage structure were significant during both years. Fish abundance and species richness were typically low under piers; YOY fishes were rare andAnguilla rostrata accounted for a large proportion of the total catch. In contrast, YOY fishes dominated collections at pile field and open-water stations, where abundance and species richness were high. These results indicate that habitat quality under the platforms of large piers (>20,000 m²) is probably poor for YOY fishes when compared with nearby pile field and open-water habitat types.     

宜居黄河科学构想

黄河问题表象于河,形成于域,根植于地。针对于黄河流域高质量发展面临的地球科学问题特点及挑战,本文提出了“宜居黄河”科学构想,旨在构建一个包括“安全黄河”、“绿色黄河”、“生态黄河”、“和谐黄河”和“智慧黄河”5大核心内容的体系完善的宜居黄河研究科学架构,并对这5个方面的科学内涵和关键研究内容进行了阐述。其中,(1)安全黄河立足于工程地质学,研究黄河流域地质地表过程及其灾害效应,以保障地质安全需求,构建安全黄河体系;(2)绿色黄河立足于水文地质学,研究黄河流域水循环过程及其水土环境变化效应,构建绿色黄河体系;(3)生态黄河立足于环境地质学,研究黄河流域生态系统演化规律及其生态屏障效应,构建生态黄河体系;(4)和谐黄河立足于资源地质学,研究黄河流域资源开发与人地协调的发展模式,构建和谐黄河体系;(5)智慧黄河立足于大数据及信息科学,研究黄河流域地学信息集成与智慧决策平台,构建智慧黄河体系。这5个部分相互支撑融合,共同解决宜居黄河的核心关键问题,从而为保障黄河长治久安、促进全流域高质量发展,最终形成造福中华民族的“幸福黄河”起到科技支撑作用。     

Influence of salt front position on the occurrence of uncommon marine fishes in the Hudson River estuary

Six species of marine fishes, the Atlantic cutlassfish Trichiurus lepturus; planehead filefish, Monacanthus hispidus; guaguanche, Sphyraena guachancho; pigfish, Orthopristic chrysoptera; freckled blenny, Hypsoblenius ionthas; and short bigeye, Pristigenys alta, were observed for the first time in the Hudson River estuary in 1985. Their occurrence was associated with low freshwater runoff and the resulting upstream penetration of the salt front to historic levels. These conditions may have facilitated the dispersal of marine fishes from coastal areas into the lower Hudson River estuary.     

Groundwater–river interaction and management in the context of inter-basin transfers

This study is focused on the management of coupled groundwater–river interaction (GRI) in the context of inter-basin transfers. The semi-coupled models, HEC-RAS and MODFLOW, were utilized in this study to replicate the River Tees experiment that had been conducted in 1976. Then the ‘surrogate’ models were applied to two “what if” scenarios in order to understand and manage GRI behavior and the nature of the reservoir control system. The results on the River Tees showed that the total temporary bankside storage volume was up to 17.5 % of the total reservoir release, given about 22 h of travel time. In addition, zones 4 and 5 of the river model with significant alluvium deposits were the best storage sites with values of 4.5 and 6.7 % of the total reservoir release, respectively, estimated as temporary losses. The final direct runoff received downstream at broken scar was about 95 % of the Cow Green total reservoir release. Furthermore, the closure rate proved to be vital to compute the effective return flow in respect of this study area. Finally, with careful reservoir and groundwater management, the River Tees proved to be an ideal natural aqueduct for inter-basin transfers when used as part of a major regional water resources scheme.     

The nursery role of seagrass meadows in the upper and lower reaches of the Chesapeake Bay

A two-year trawling and gill-netting study of vegetated and unvegetated bottoms near Parson’s Island, Maryland and near the mouth of the York River, Virginia was carried out to assess the nursery function of submerged vegetation for populations of fishes and decapod crustaceans in the Chesapeake Bay. Results revealed that vegetated bottoms supported substantially larger numbers of decapods, but not fishes, than unvegetated substrates. The lower Bay grassbed was an important nursery area for juvenile blue crabs, although neither of the grassbeds functioned as a nursery for commercially or recreationally valuable fishes. Our results suggest that: (1) further decreases in lower Bay Seagrass biomass would result in reduced numbers of adult blue crabs, but should not substantially affect populations of valuable fish species; (2) additional decreases in Upper Bay submerged vegetation should not produce dramatic change in the population sizes of either adult blue crabs or fishes.     

Fish community ecology in an Altered River delta: Spatial patterns in species composition, life history strategies, and biomass

We sampled nearshore fishes in the Sacramento-San Joaquin Delta, California, United States, during 2001 and 2003 with beach seines and gill nets. We addressed three questions. How and why did fish assemblages vary, and what local habitat features best explained the variation? Did spatial variation in assemblages reflect greater success of particular life history strategies? Did fish biomass vary among years or, across habitats? Nonmetric multidimensional scaling showed that habitat variables had more influence on fish assemblages than temporal variables. Results from both gear types indicated fish assemblages varied between Sacramento and San Joaquin River sampling sites. Results from gill net sampling were less pronounced than those from beach seine sampling. The Sacramento and San Joaquin river sites differed most notably in terms of water clarity and abundance of submerged aquatic vegetation (SAV), suggesting a link between these habitat characteristics and fish relative abundance. Among-site differences in the relative abundance of periodic and equilibrium strategist species suggested a gradient in the importance of abiotic versus biotic community structuring mechanisms. Fish biomass varied among years, but was generally higher in SAV-dominated habitats than the turbid, open habitats in which we found highest abundances of striped bassMorone saxatilis and special-status native fishes such as delta smeltHypomesus transpacificus, Chinook salmonOncorhyncus tschawytscha, and splittailPogonichthys macrolepidotus. The low abundance of special-status fishes in the comparatively productive SAV-dominated habitats suggests these species would benefit more from large-scale restoration actions that result in abiotic variability that mirrors natural river-estuary habitat than from actions that emphasize local (site-specific) productivity.     

Epibenthic fishes and decapod crustaceans in northern estuaries: A comparison of vegetated and unvegetated habitats in maine

Species richness and abundance of epibenthic fishes and decapod crustaceans were quantified with day-time beam trawl tows and throw traps to provide information on nekton assemblages inZostera marina and unvegetated sandy habitats in northern latitudes. Sampling at randomly selected stations with a 1.0-m beam trawl occurred in eelgrass (Zostera marina) and unvegetated sandy substrates of two mid-coastal Maine estuaries: Casco Bay and Weskeag River. Random 1.0-m throw trap samples were collected inZostera and adjacent unvegetated sandy substrates in Casco Bay and Weskeag River as well. Species richness and faunal abundances were positively associated with the occurrence ofZostera within Weskeag River and Casco Bay estuaries using both gear types. A total of 17 species of fishes and 6 species of decapods were collected in the two estuaries using both gears. Populations of most species were dominated by young-of-the-year and juvenile life history stages. Number and densities of fishes were higher inZostera, due primarily to the abundances of eelgrass residents such as threespine,Gasterosteus aculeatus, and fourspine sticklebacks,Apeltes quadracus, grubby,Myoxocephalus aenaeus, and cunner,Tautogolabrus adspersus. Crangon septemspinosa dominated decapod catch per unit effort and density in both estuaries and habitats.     

The fluvial and geomorphic context of Indian Knoll,an Archaic shell midden in West‐Central Kentucky

Indian Knoll is the largest Archaic shell midden excavated by WPA archaeologists in Kentucky. Situated in a large alluvial valley, the site is not associated with a known river shoal as might be expected, making its fluvial and geomorphic setting of interest. Based on sediment cores and auger samples, undisturbed portions of the site remain despite extensive excavations. In undisturbed portions, a shell‐bearing layer is overlain by a shell‐free midden layer. Profiles of organic matter and calcium carbonate content for both layers are similar to those of other Green River shell middens. New radiocarbon determinations date the shell deposit at 5590–4530 cal yr B.P. Analysis of mussel species collected from the Indian Knoll indicates that shell fishing took place in a swiftly flowing, shallow to moderately deep setting of the main river channel. Overall, the prehistoric river setting adjacent to Indian Knoll was characterized by deeper water on average with variable but finer‐grained substrate compared to other Green River shell midden sites. © 2002 Wiley Periodicals, Inc.     

Late glacial impacts on dispersal and colonization of Atlantic Canada and Maine by freshwater fishes

Late glacial scenarios of ice retreat and biogeography databases constrain the dispersal routes of obligate freshwater fishes into Atlantic Canada and Maine. Evidence indicates glacial ice covered the present-day mainland and offshore islands at 18,000 ¹⁴C yr before present. Possible refugia for extirpated freshwater fishes were the exposed outer edge of the Grand Banks (east), exposed Georges Bank (south-Atlantic Refugium), and the Mississippi Refugium in the west. It is improbable that the region was recolonized from the offshore refugia. Rather, fishes recolonized from the east via the upper St. Lawrence River valley into the upper Saint John River, Maine (Lake Madawaska) from 11,000 to 12,000 ¹⁴C yr BP. The short period of entry resulted in the low diversity of obligate freshwater species in the region. Lake Madawaska was breached and dispersal continued into the remainder of the region after 8000 ¹⁴C yr BP. By 6000 ¹⁴C yr BP, access routes to the east along low-lying coastal zones were blocked by rising sea levels, which isolated Prince Edward Island, Cape Breton Island, and most probably Nova Scotia. Natural dispersal across the region appeared complete by this time.     

页岩沉积环境对其油气潜力的影响:以中国和北美对比研究为例

页岩油气是当前全球油气勘探和研究的热点,但其潜力评价一直是难点。该文以中国和北美的四套典型页岩为例,包括北美湖相Green River组、内陆海相Niobrara组、中国环境来评价相龙马溪组和济阳坳陷湖相页岩,发现页岩沉积环境与其油气潜力具有密切关系,因此可通过分析发现这四套页岩的沉积环境都具有页岩沉积环境评价其页岩油气潜力。通过微量元素、生物标志化合物、扫描电镜、X-CT和X射线衍射等方法,发现这四套页岩都具有一定的还原性和较高的生产力,且具有差异性。内陆海相Niobrara组页岩具有弱还原的沉积环境,在四套页岩中有机碳含量较低,呈块状沉积构造,裂缝与微裂缝较少,储集空间相对有限。焦石坝海相龙马溪组页岩为还原的沉积环境,岩石以富含有机质的硅质岩为主,可观察到大量的大孔隙与少量的微裂缝。Green River页岩和济阳坳陷页岩形成于陆相咸化的强还原沉积环境,有机碳含量高,页岩以纹层状结构为主,岩石组成脆性矿物含量高,含有大量的裂缝。可见,具有强还原沉积环境的页岩通常具有较好的勘探前景。     

塔里木河下游生态环境整治与生态效应分析

塔里木河(简称塔河)下游生态环境问题十分突出，综合治理势在必行．根据塔河下游现状。针对塔河治理已经实施的一系列措施，运用对比分析方法探讨了各类治理措施的实效，并着重对应急输水工程的实施所带来的生态效应及存在问题进行分析．提出塔河下游生态环境综合治理的几点建议。     

The effect of maturation on the configuration of pristane in sediments and petroleum

The absolute stereochemistry of pristane in a sample of contemporary marine Zooplankton, Messel shale (Germany) and Djatibarang (Java) crude has been determined by gas Chromatographic methods. The relative stereochemistry in Irati shale (Brazil), Green River (U.S.) crude, Halibut (Australia) crude has also been determined, and confirmed for a sample of the Green River shale. The stereoisomer distributions indicate a loss of stereospecificity of the phytol-derived 6(R),10(S) pristane with increasing geological maturation. For example, the least mature geological sample, the Eocene Messel shale, contains solely the 6(R),10(S) isomer, whereas a mature sample, Djatibarang crude, contains 50% of the 6(R),10(S) isomer and 25% of each of the 6(R),10(R) and 6(S),10(S) isomers.     

长江中华鲟栖息地适合度模型研究

对与水生生物生存栖息相关的河流底质、水深、水温、流速、水质等生态因子进行研究。提出水生生物的栖息地适合度模型,从生物生存栖息地影响角度对河流治理工程进行科学的评价。以长江珍稀动物中华鲟为研究对象,通过对影响中华鲟的各种生态因子的统计研究,分析整理出适宜其生存繁殖的河流水温、水深、底质、流速、含沙量及食卵鱼10个因子的临界指标,得出了这些因素的适合度曲线。发展了适合评价长江中华鲟栖息地的适合度方程,并用12组实测数据对模型进行了修改验证,提出了适合评价长江中华鲟栖息地适合度模型。     

Stereochemical studies of acyclic isoprenoid compounds—V. Oxidation products of Green River Formation oil shale kerogen

Gas chromatographic analysis of the major isoprenoid carboxylic acids and the major ketone (6,10,14-trimethylpentadecan-2-one), derived from successive chromic acid oxidations of the kerogen of Green River Formation oil shale, indicates that their stereochemistry is compatible with the hypothesis that phytol or a derivative with the same carbon skeleton and stereochemistry was incorporated into the kerogen matrix.     

绿河油页岩中的开链醇化合物

研究了美国绿河盆地的23个未成熟的露头油页岩样品,其中 13个样品取自Laney组,为半温湿半干燥气候下沉积于较浅的封闭水体的盐湖中心,含有丰富的有机质;另外 10个样品取自LumanTongue组,为潮湿气候下沉积于近岸的水体开放的淡水环境,其有机质含量较低。所有样品均富含从C₁₁至C₂₀ 的同分异构体丰富的饱和类异戊二烯醇类化合物。此外还检出了一整套直链一元仲醇同系物,其碳数从 10至 33,而羟基可在任何理论上可能的碳位上。伯醇含量较低。研究结果表明,绿河油页岩中的有机质分别在沉积过程中和被抬升之后遭受了两次微生物降解。除伯醇的分布有生物来源特征外,其余的开链醇化合物是在绿河层系抬升至地表后微生物对其中烃类化合物降解的产物。文中将绿河油页岩有机质中异常高的氧指数归因于微生物降解,并探讨了其开链醇化合物的分布与物源、沉积环境及微生物降解程度的相关性。盐湖相Laney组的直链醇以低碳数组分为主,反映其有机质以菌藻为主的物源,与干燥的古气候相一致;淡水相LumanTongue组则以高碳数组分为主,有着明显优势的高等植物来源,与其潮湿的古气候相吻合。在沉积过程中,淡水相的LumanTongue组中的有机质遭受了比盐湖相的Laney组中的有机质更强的微生物降解,这意味着盐湖环境。