经济发展影响下我国海洋环境污染压力变化趋势及污染减排对策分析

对20世纪90年代以来我国经济发展影响下的海洋环境污染变化趋势进行了分析,指出近年来我国海洋环境污染防治工作取得了一定成效,但近岸海域污染的总体形势依然严峻,并可能随着经济总量的增长而再次恶化,氮磷营养盐超标导致的海水富营养化是近岸海域的主要污染问题。讨论了我国现行的污染物减排策略对海洋污染防治的局限性,并以国家"十二五"发展规划、沿海区域社会经济发展规划为依据,综合分析"十二五"期间我国海洋环境污染防治面临的压力和主要入海污染源的排污特征,建议应对农业非点源开展源头污染控制、对沿海地区点源加强末端治理,实施流域-河口-海域联动的入海污染物减排策略。     

Fracture detection by Gaussian beam imaging of seismic data and image spectrum analysis

Localization of fractured areas is of primary interest in the study of oil and gas geology in carbonate environments. Hydrocarbon reservoirs in these environments are embedded within an impenetrable rock matrix but possess a rich system of various microheterogeneities, i.e., cavities, cracks, and fractures. Cavities accumulate oil, but its flow is governed by a system of fractures. A distinctive feature of wave propagation in such media is the excitation of the scattered/diffracted waves by the microheterogeneities. This scattering could be a reliable attribute for characterization of the fine structure of reservoirs, but it has extremely low energy and any standard data processing renders them practically invisible in comparison with images produced by specular reflections. Therefore, any attempts to use these waves for image congestion of microheterogeneities should first have a preliminary separation of the scattering and specular reflections. In this paper, the approach to performing this separation is based on the asymmetric summation. It is implemented by double focusing of Gaussian beams. To do this, the special weights are computed by propagating Gaussian beams from the target area towards the acquisition system separately for sources and receivers. The different mutual positioning of beams in each pair introduces a variety of selective images that are destined to represent some selected singular primitives of the target objects such as fractures, cavities, and edges. In this way, one can construct various wave images of a target reservoir, particularly in scattered/diffracted waves. Additional removal of remnants of specular reflections is done by means of spectral analysis of the scattered/diffracted waves' images to recognize and cancel extended lineaments. Numerical experiments with Sigsbee 2A synthetic seismic data and some typical structures of the Yurubcheno‐Tokhomskoye oil field in East Siberia are presented and discussed.     

桂东南射广嶂伸展滑脱韧性剪切带探讨

文章介绍了在桂东南1:5万长山幅、那卜幅区调过程中,首次在射广嶂一带识别出4条规模较大的伸展滑脱型韧性剪切带和一系列小型顺层韧性剪切带,这是该地区地质研究的重要突破.通过野外调研和室内综合分析,详细叙述了这些韧性剪切带的构造样式、岩石组合、显微组构以及韧性变形过程中的岩石转变等,初步探讨了韧性剪切带的应变、形成环境和变形机制.     

山东长岛潮间带大型底栖动物生态特征研究

2015年11月(秋季)、2016年2月(冬季)、2016年6月(春季)、2016年9月(夏季)大潮期间对山东长岛列岛中南长山岛和北长山岛的3个不同底质类型的潮间带采样点进行了系统的大型底栖动物调查,研究了其数量特征和季节变化,包括群落种类组成、密度和生物量、优势种、物种多样性等,结果表明:本次调查共鉴定出大型底栖动物隶属7个门,共81种。其中环节动物门多毛类动物25种,软体动物门25种,节肢动物门22种,棘皮动物门6种,其他类群共3种(包括纽虫、腔肠动物和鱼类各1种)。潮间带大型底栖动物平均密度为118.97 ind./m~2,软体动物和甲壳动物占据了研究区域底栖群落的密度主要成分,两者分别占比为39.58%和36.68%。各采样点平均密度为北长山岛(BCS)(141.17 ind./m~2)避险角(NCS1)(122.33ind./m~2)明珠广场东(NCS2)(93.42ind./m~2);各采样点平均生物量为128.03g/m~2,软体动物和甲壳动物占据了研究区域底栖群落的生物量主要成分,两者分别占比为58.56%和35.32%。平均生物量北长山岛(BCS)(234.95g/m~2)避险角(NCS1)(99.99g/m~2)明珠广场东(NCS2)(49.13g/m~2)。从季节来看,各站点的物种数、平均密度和生物量季节变化的规律性不明显,总体为秋、春季较多,夏、冬季较少。3个站点物种多样性指数(H′)、丰富度指数(D)和均匀度指数(J′)平均值分别为2.30、1.99和0.79,各潮区中,均为中潮带低潮带高潮带,各季节变化不明显。优势种受底质类型和季节变化的影响明显,没有在各站点和季节均为优势种的种类,主要的优势种有平背蜞(Gaetice depressus)、绒螯近方蟹(Hemigrapsus penicillatus)、短滨螺(Littorina brevicula)等。与以往历史资料相比,长岛潮间带生物出现了一定变化,种类和数量减少,与烟台近岸潮间带大型底栖动物种类组成差别很大。     

生态屏障约束下的综合功能区划研究——以云南省昭通市为例

Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reaches of the Yangtze River became one of the most important tasks of Western Development strategy. This article, taking Zhaotong as an example, studies the functional regionalization of ecological shelter zones. The study supplies a case for functional regionalization of small and medium regions whose main tasks are environment reservation. With the guidance of theories of functional regionalization, and based on the analysis of Zhaotong＇s natural, ecological and socioeconomic factors, the paper suggests five principles for factors selection. These principles include： （1） reversing order evaluation; （2） selecting main factors; （3） keeping the integrality of administrative regions of towns; and （4） making the products acceptable by local government. To analyze spatial status of selected factors, LUCC data in 2002, 1：50,000 relief maps and town-unit socioeconomic statistical data in 2004 are used. RS and GIS tools are also applied to melt traditional and modern geographical methods. This would be useful to functional regionalization research in mountainous areas. As a conclusion, the leading functional regions of ecological conservation or economic development are suggested, respectively. Zhaotong city is divided into two-level functional regions. The first-level includes three leading functional regions and they will lead developing direction of sub-regions. The second-level includes eight sub-regions, which are policy implemented regions, and will supply guidance to Zhaotong＇s ecological shelter zones reconstruction.     

云南牟定县戌街晶质石墨矿特征及找矿标志

云南牟定县戌街石墨矿矿体形态多呈层状、似层状,主要赋存于前震旦系苴林群普登组第二段第三层(Pt p2-3)中,矿体产状与地层产状基本一致.矿石工业类型为细鳞片晶质石墨矿,矿床成因属区域(沉积)变质型矿床,地层层位和特征变质矿物组合是主要找矿标志.     

Oxygen minimum zones in the eastern tropical Atlantic and Pacific oceans

Within the eastern tropical oceans of the Atlantic and Pacific basin vast oxygen minimum zones (OMZ) exist in the depth range between 100 and 900 m. Minimum oxygen values are reached at 300–500 m depth which in the eastern Pacific become suboxic (dissolved oxygen content <4.5 μmol kg⁻¹) with dissolved oxygen concentration of less than 1 μmol kg⁻¹. The OMZ of the eastern Atlantic is not suboxic and has relatively high oxygen minimum values of about 17 μmol kg⁻¹ in the South Atlantic and more than 40 μmol kg⁻¹ in the North Atlantic. About 20 (40%) of the North Pacific volume is occupied by an OMZ when using 45 μmol kg⁻¹ (or 90 μmol kg⁻¹, respectively) as an upper bound for OMZ oxygen concentration for ocean densities lighter than σ_θ < 27.2 kg m⁻³. The relative volumes reduce to less than half for the South Pacific (7% and 13%, respectively). The abundance of OMZs are considerably smaller (1% and 7%) for the South Atlantic and only 0% and 5% for the North Atlantic. Thermal domes characterized by upward displacements of isotherms located in the northeastern Pacific and Atlantic and in the southeastern Atlantic are co-located with the centres of the OMZs. They seem not to be directly involved in the generation of the OMZs.OMZs are a consequence of a combination of weak ocean ventilation, which supplies oxygen, and respiration, which consumes oxygen. Oxygen consumption can be approximated by the apparent oxygen utilization (AOU). However, AOU scaled with an appropriate consumption rate (aOUR) gives a time, the oxygen age. Here we derive oxygen ages using climatological AOU data and an empirical estimate of aOUR. Averaging oxygen ages for main thermocline isopycnals of the Atlantic and Pacific Ocean exhibit an exponential increase with density without an obvious signature of the OMZs. Oxygen supply originates from a surface outcrop area and can also be approximated by the turn-over time, the ratio of ocean volume to ventilating flux. The turn-over time corresponds well to the average oxygen ages for the well ventilated waters. However, in the density ranges of the suboxic OMZs the turn-over time substantially increases. This indicates that reduced ventilation in the outcrop is directly related to the existence of suboxic OMZs, but they are not obviously related to enhanced consumption indicated by the oxygen ages. The turn-over time suggests that the lower thermocline of the North Atlantic would be suboxic but at present this is compensated by the import of water from the well ventilated South Atlantic. The turn-over time approach itself is independent of details of ocean transport pathways. Instead the geographical location of the OMZ is to first order determined by: (i) the patterns of upwelling, either through Ekman or equatorial divergence, (ii) the regions of general sluggish horizontal transport at the eastern boundaries, and (iii) to a lesser extent to regions with high productivity as indicated through ocean colour data.     

甘肃省成矿区(带)研究

成矿区（带）是区域成矿学的核心内容,成矿区（带）的划分和研究是成矿规律认识的深化和科学表达,同时是具有矿产资源潜力的成矿单元,是服务于勘查决策的主要载体。文章根据全国成矿区（带）划分意见,对甘肃涉及的4个成矿域、8个成矿省及12个Ⅲ级成矿区带进行分析和研究,依据省内区域矿产空间分布的集中性和区域成矿作用的统一性原则,重点讨论矿床所处的大地构造环境、成矿作用与区域地质演化过程、容矿围岩时空分布一致性或相似性;参考区域地球化学场、地球物理场特征,划分Ⅳ级成矿区（带）26个,Ⅴ级成矿区（带）94个。明确各级成矿区带地质意义及显著特征。文章指出本次对甘肃省成矿区带的划分具有探索性,随着认识不断深化,成矿区带的研究和厘定将更加科学。     

主体功能视角下皖南旅游区乡村多功能演化特征与影响机制

以皖南旅游区为研究对象,通过构建主体功能县域旅游地乡村多功能研究框架及其指标体系,采用多指标综合评价、热点分析、地理探测器等方法,对比分析不同主体功能区乡村多功能差异特征、影响因素、类型模式,并提出提升路径.结果 发现:①2006-2017年,不同功能结构在各类主体功能区差异明显,旅游休闲功能比重不断增长,农业生产和生...     

华北地台五台、中条、集宁区前寒武系铀矿化与找矿方向的讨论

本文首先概述了寒武纪地质发展史。太古代早期只出现小面积古陆核,岩石含铀量低,硅铝壳演化晚。早元古代稳定性差,盖层形成晚。因此,对寻找澳北型铀矿床不利。但中生代地台活化对寻找花岗岩型铀矿床创造了条件。铀矿花分布在古陆核两侧,围绕古陆核划分三个分带:内带——太古代古陆核为钍矿化区,多为花岗伟晶岩型;中带——古陆核边缘凹陷为铀钍混合区,铀多为变质热液型,碱交代型,与硅化带、破碎带、混合岩化及岩体接触带有关;外带——中生代花岗岩分布区为铀矿化区。中生代化岗岩是本区主要成矿岩体。集宁区凤凰山岩体,铀矿化分布于岩体边缘顶盖相,属硅质脉型。五台区盘道岩体,铀矿化主要产于岩体外接触带,有萤石型与玉髓型两种。上述共同特点:富硅、富钾、铝过饱和岩石,成矿类型与岩石化学成分都可与华南花岗岩对比。铀矿找矿方向:主要在古陆核外带中生代花岗岩呈北东向展布区,特别是围绕花岗岩内外接触带,寻找硅质脉型是最有远景的。其次是在中条区西侧山前大断裂复背斜核部,特别是断裂拐弯处和混合岩化强烈地段,寻找变质热液型、碱交代型是比较有利的。