Topography, exhumation, and drainage network evolution of the Apennines

The present-day topography of the Italian peninsula results from the interactions between crustal-mantle and surface processes occurring since the Late Miocene. Analysis of exhumation and cooling of crustal rocks, together with Quaternary drainage evolution,helps to unravel the tectonic-morphologic evolution of the Apennines by distinguishing end-member models,and hence describing the orogenic belt evolution. The pattern of regional topography, erosional history and present-day distribution of active deformation suggests that the eastward migrating extensional-compressional paired deformation belts may still control the topogra-phy of the northern Apennines, albeit at slower rates than in the past. Conversely, Quaternary drainage evo-lution in the central and southern Apennines suggests that the topography of these regions underwent a Quaternary regional arching, which is only partly con-sistent with the persisting migration of the compres-sional-extensional pair.     

地面沉降——一地面沉降类型

地面沉降是地面由于地下物质运移而发生的渐进下陷或急剧下沉。这是一个全球性问题，仅在美国，已经有遍及45个州，超过44030km0的土地受到了地面沉降的影响，相当于新汉布什尔州与佛蒙特州的总和。由此引发的经济损失更是惊人：仅在圣克拉拉山谷，沉降所造成的直接经济损失，在1979年大约为1．31亿美元，而到了1998年则高达3亿美元。造成这一灾害的原因主要有含水层的压实、有机质土的疏干排水、地下采矿、自然压实、溶坑以及永冻土的解冻等。     

Evolution of mine-pool chemistry at the Sydney Coalfield, Nova Scotia, Canada, and its implications for mine decommissioning

The Sydney Coalfield is the largest in Atlantic Canada in which about 100 coal mines with varied lifespan have been opened since 1720. In the Glace Bay sub-basin, coal seams subcrop close to the Atlantic coast and dip seaward. Coal has been mined at 〉1200 m depth and 11 km from the coastline. Deposited possibly under a marine influence, the coals are enriched in pyrite. During mining abundant acidic sulfates such as melanterite, rozenite, copiapite and halotrichite have accumulated in the underground workings due to pyrite oxidation. The dissolution of these efflorescent salts upon mine flooding at closure gives rise to acidic mine pools wherever insufficient acid-neutralizing materials are present. A major challenge of mine decommissioning in the area is to prevent the discharge of this acidic water into the open ocean. Water monitoring in the 1B Hydraulic System, which consists of ten mines connected at various depths by natural or man-made conduits, shows that the mine pool chemistry varies with the mining practice employed. Although coal has invariably been mined by the room and pillar method, the extent of pillar removal varies from mine to mine. In mines with minimal pillar removal, coal extraction could be as low as 45%, leaving much pyrite for oxidation prior to eventual flooding and an acidic mine pool occurs. In contrast, in mines with extensive pillar removal, coal extraction could amount to 85%, leaving much less pyrite for oxidation. Moreover, the extensive pillar removal caused the collapse of the overlying strata which in some areas include limestone. The infilling of mine workings with carbonate-rich material offsets the effects of acidic effiorescent salts and a mine pool with near-neutral pH results. Geochemical modeling has affirmed the control of local water chemistry by the prevalent mineral assemblage.     

Moessbauer and XRD characterization of contaminated sediments by coal mining drainage in Neath Canal, South Wales, UK

Sediment cores were collected from the upstream of the Neath Canal in South Wales and characterized for their mineral compositions and iron speciation in order to understand the influence of sedimentary properties on the contaminants of heavy metals. The sediments in the canal have been polluted by ocherous precipitate with heavy metals such as arsenic since a major mine water discharge in spring 1993. The sediment core was obtained just from the discharge point in the canal and distinguished into three layers in the field regarding to their physical properties including visible color, sediment particle composition and dryness. X-ray diffraction （XRD） and M6ssbauer spectroscopy revealed vertical variations of minerals and iron species in depth of the sediment profile. The upper layer, reddish-brown, is wet muddy precipitant and is very fine in particle size, consisting mainly of iron oxide and hydroxide. Arsenic is rich in this layer; probably the sorption on iron oxide surface is the main mechanism. The middle layer, 22.0-27.0 cm, is soft deposit in a yellow color and contains sheet silicate, calcite and goethite. The lower part below 27.0 cm is gray to dark gray in color and contains quartz, pyrite, coal particles that are much more similar to normal aquatic sediment. The upper two layers in brown and yellow colors as newly precipitated mud from AMD contain high concentrations of As, Ni under oxic conditions. The lower part as the old canal sediments under reducing conditions contains high Cu and Zn. Chromium is enriched in the limited part of the low layer, just beneath the boundary between the middle and low parts of the sedimentary column, where the redox conditions shifted from oxic to anoxic. It is clear that the distribution of these heavy metals is closely associated with the redox condition reflected in the iron speciation. Thus different treatments are necessary for each layer of the sediment since different mineral and geochemical properties of the sediment will give different impacts on the heavy metals.     

Water quality evolvement from Huangpu River, Shanghai, China

The Huangpu River supplies eighty percent of daily water used for life and industry for about 20 million people in Shanghai, China. Industry and domestic sewerage from the metropolis is mainly released into the Huangpu River, which flows through the Shanghai City area. The pollution caused by city life and production in the Huangpu River has occurred for years. In this paper, the contents of heavy metals （Cu, Pb, Cr, Cd, and Hg）, total organic carbon （TOC）, and polynuclear aromatic hydrocarbons （PAHs） in the Huangpu River are studied. Data from environmental monitoring from 1991 to 2002 are compared to understand the variation and trends of the pollution. Results indicate that metals have been reduced efficiently, but organic pollutants develop in an aggravating trend as domestic sewage increases. The variation of the organic pollutant concentrations, which are lower than those of other similar rivers of China, US, and Canada,     

招远市金矿采、选废水的利用与管理

主要介绍招远市金矿矿坑外排废水水质、利用现状及金矿洗选废水对环境的污染问题。多年监测结果表明,招远市金矿矿坑水二次污染程度较轻,外排水水质全部符合农田灌溉和选矿用水的水质标准,部分还可作生活饮用水利用;区内金矿选矿废水中,氰化废水CN、Cu严重超标,浮选外排废水虽实现了达标排放,但总硬度、矿化度、Ca^2＋及硫酸盐等成分含量普遍较高,对地下水仍有一定的污染作用。现场浸染试验结果反映出废水排放后在自然环境下的自然降解过程较短,对地下水影响局限于较小的范围内。     

矿山尾矿矿物学研究进展

矿山尾矿由于产生大量酸性排水和释放重金属，污染地下水和地表水，破坏生态环境而成为人们关注的焦点。尾矿引起的环境问题是地表条件下，水一气一矿物复杂反应的综合结果。近年来尾矿矿物学的研究已经揭示出尾矿中矿物分解和形成的规律，水一气一矿物反应的机制和影响因素，酸性排水和重金属迁移规律，为尾矿环境危险性评价和尾矿污染防治提供了基础资料和新的思路。     

《地下水》编委简介

方生—河北省水利科学研究院教授级高级工程师。水资源与灌溉排水专家,《地下水》杂志编委。1928年1月出生于山东青岛市。1945、1947肄业于天津工商学院建筑工程系、河北工学院水利工程系。水利部地下水专家组成员、世界银行国际灌溉排水技术研究计划(IPTRID)专家组成员、全国地下水信息网顾问。曾任水利部土壤调查总队副总队长,河北省水利厅勘测设计院试验室、综合设计室、科研室主任,河北省水利科学研究所所长,中国水利学会农田水利专业委员会委员、中国土壤学会盐碱土专业委员会副主任、河北省农业系统工程学会副理事长等。上世纪50年代参与水利部与中国科学院合作组织华北平原、内蒙古河套、宁夏青铜峡引黄灌区及山西河谷盆地土壤地下水调查。为黄河中下游灌区开发、根治海河、旱涝盐碱综合治理提供科学依据。参加编著《华北平原土壤》,获全国科学大会奖。60年代组织海滦河平原防治土壤盐碱化调查与科学实验。在河北深县组建后营旱涝盐碱综合治理试区,解决了灌区次生盐碱化防治问题。十年实现人均千斤粮,二十年粮食总产翻两番。后营试区获河北省科技工作先进集体先进个人代表会议奖。70年代主持国家河北黑龙港地区地下水合理开发利用的研究,《综合治理旱涝碱咸》...     

铜陵矿山酸性排水及固体废弃物中的重金属元素

在调查中国铜陵凤凰山铜矿和新桥硫铁矿两种不同类型矿山固体废弃物特征的基础上,研究了矿山尾矿和废石产生酸性排水的可能性及其差异以及矿山固体废弃物中重金属元素的赋存形式。结果表明,凤凰山铜矿的尾矿基本不产生矿山酸性排水,而新桥硫铁矿采矿废石产生矿山酸性排水,并且凤凰山铜矿的尾矿和新桥硫铁矿采矿废石中重金属元素的赋存形式也有差异,前者重金属Cu、Pb、Zn、Cd、As、Hg主要赋存于硅酸盐态中,而后者在还原态中有较高的含量,这反映了在地表条件下尾矿中大量重金属元素已经发生了迁移,而采矿废石已经开始氧化,且酸性排水的存在更有利于废石中重金属元素的迁移和扩散,进而导致矿区周围环境的污染。