浙江缙云老虎头—天王背古火山机构与沸石—珍珠岩矿床

缙云老虎头矿区是首次在我国发现的沸石岩矿产地。近年来,通过对中国东南部火山岩区的地质勘查工作,又发现了为数众多的缙云式沸石-珍珠岩矿床。因此,对该矿床进行典型解剖,具有特别重要的意义。本文着重阐述老虎头-天王背古火山机构及其沸石-珍珠岩矿床的地质特征。 一、老虎头—天王背古火山机构 老虎头-天王背古火山机构的区域构造位置隶属于北北东向丽水—余姚断裂火山喷发带,处于靖岳-舒洪构造火山盆地的北部边缘。是盆地内以马鞍山主火山口为中心的     

内蒙古鄂伦春旗库伦迪铅锌矿床矿石特征研究

大兴安岭成矿带是我国重要的有色金属成矿带之一,库伦迪铅锌矿床是近年来在该带北段中发现的中型矿床之一。本文在系统的野外地质调查的基础上,对该矿床的矿石开展详细的矿石特征研究。结果表明:库伦迪矿床矿石可划分为锌铅矿石、锌铅铜矿石、铜锌矿石和铅矿石等4种类型;各矿石类型矿物共生组合分析表明,按成因该矿床矿石结构可分为结晶结构、交代结构、固溶体分离结构和压碎结构;矿石构造以细脉状构造、浸染状构造、块状构造和团块状构造为主,条带状构造次之。综合矿物学特征,将成矿期次划分为两期:第一成矿期为闪锌矿—黄铜矿成矿期,并划分为辉钼矿—磁铁矿成矿阶段、黄铁矿—闪锌矿成矿阶段、闪锌矿—黄铜矿成矿阶段;第二成矿期为方铅矿成矿期,主要有方铅矿、黄铁矿、闪锌矿、黄铜矿等。     

广东长埔锡矿床锡石标型特征

长埔锡矿床锡石的结晶习性、物理性质、化学成分和稀土元素地球化学特征等研究表明,①矿床中多数锡石表现为锡石—石英型,应属于锡石—石英型矿床。②锡石明显可分为两种,这两种锡石是矿床两期矿化的具体表现。③锡石稀土元素地球化学特征等反映成矿物质主要来自地层。     

江西省广丰县李家膨润土矿床成因及找矿标志

广丰县李家膨润土矿床赋存于白垩系上统南雄组第二岩性段酸性火山岩的顶底部.膨润土的主要矿物成分为蒙脱石,矿石结构构造与成矿原岩有关.矿石化学成分与酸性熔岩相近,矿体形态及空问分布受酸性熔岩流相带的控制.因此认为,膨润土矿床成矿原岩为酸性玻质熔岩,矿床是由酸性玻璃质熔岩经水解脱玻化而形成,其成因类型为风化淋滤蚀变岩型矿床.膨润土可自然改型,由原来的钠基膨润土改型成钙基膨润土和偏镁的钙基膨润土.对时代较新的酸性火山岩,在玻质熔岩发育处都有可能找到有利用价值的膨润土矿.由于膨润土常由珍珠岩、沸石脱玻化形成,三者常共生出现,是很好的找矿标志.     

江西修水县梅子坑钼矿床地质特征及成因初探

梅子坑钼矿位于九岭钨钼成矿带,为中型石英脉型钼矿床.矿区内地层和岩浆岩钼元素含量分别是克拉克值的43倍和21倍.矿体赋存于双桥山群修水组浅变质岩系中及北西向断裂控制的裂隙密集带中;矿石主要类型为石英脉型,矿石有益组分为辉钼矿,形成于石英-黄铁矿-辉钼矿-黄铜矿早期矿化阶段.矿床可能与隐伏的燕山期细粒花岗岩、花岗斑岩岩脉有成因关系,属与燕山期岩浆活动有关的中-高温热液矿床.北西向断裂密集带,硅化、云英岩化、黄铁矿化围岩蚀变,燕山期花岗岩类及双桥山群浅变质岩系,是其主要找矿标志.     

川滇地区密西西比河谷型铅锌矿床成矿地质背景及成因探讨

川滇地区密西西比河谷型铅锌矿床具有明显的层控性和岩控性 ,大多数矿床都赋存于灯影组白云岩中。矿床的形成温度比较低 ,主成矿阶段的温度为 140～ 2 0 0℃ ,而且各矿床的形成温度十分接近。矿床发育大规模的白云石化。本区的地质演化经历了双层基底、连续盖层 ,以及前陆盆地 -造山带耦合几个主要演化阶段。这些阶段分别为矿床的形成提供了物质基础、流动通道以及流体驱动力 ,从而在燕山期 -喜山期由于成矿流体的大规模流动 ,形成了川滇地区大面积分布的密西西比河谷型铅锌矿床。     

江西修水花山洞钨矿床同位素年代学研究及其意义

江西修水花山洞钨矿床是近年来新发现的钨矿床,与华南地区大量钨矿床与燕山期岩浆活动相关的传统认识不同,该矿床形成于晋宁期,成矿作用与晋宁期岩浆作用密切相关。本文通过对该矿区与成矿作用关系密切的花岗闪长岩和矿体矿石中辉钼矿同位素年代学研究,获得了花岗闪长岩LA-ICP-MS锆石U-Pb同位素加权平均年龄为863±18 Ma(MSWD=0.024)、辉钼矿Re-Os同位素加权平均年龄为805±5 Ma(MSWD=1.01)。结果表明,花山洞钨矿床成矿年龄略晚于矿区花岗闪长岩,显示了成矿作用与花岗闪长岩分异演化一致,花山洞钨矿床成矿时代为晋宁期,是晋宁期岩浆活动的产物。     

论长江中下游地区含铜黄铁矿型矿床成因

本义从产于石炭纪地层小的含银黄铁矿矿床的土要地质特征、侵入岩与成矿关系以及稳定冈位索特征等人面的研究提出，该类矿床具有明显的沉积特征；成矿元素流主要来自石炭纪海水，成矿金属元素主要来自下优地层，成矿流体以大气降水为主，成矿热动力主要是岩石中积累的热能和穿切地壳易透区下面而来的热能（包括海西期火山活动所形成的地热场）；矿床属海底喷气（热水）沉积成国．燕山期侵入岩对其有不同程度的叠加改造。同时阐述了该类矿床的成因机制。     

浙江省妙西多金属矿床成矿模型及找矿标志

笔者通过大量地质、地球化学、球物理和矿床(点)资料研究,提出浙江省妙西多金属矿床成矿模型,该模型正在为普查项目所证实.妙西多金属矿矿床是典型的岩浆期后热液矿床,矿体主要受本区的三级构造即岩体接触带构造和地层不连续界面构造控制.地球物理测量提供的深部信息和地质构造标志是本区多金属矿直接找矿标志,地表物化探资料在普查工作中可以起辅助作用.     

云南墨江金矿床的同位素地球化学及成因探讨

墨江金矿的同位土地球化学特征、成矿元素组合和包裹体成分表明：成矿物质主要未源于金厂蚀变起基性岩体，成矿热液是深源流体、岩浆水和大气降水混合的产物。成矿期深部富矿化剂流体沿断裂上升并与地下水混合，从侵入体及围岩中淋滤出了成矿物质。在迁移过程中，随着地球化学条件的改变，金在有利部位沉淀富集形成矿床。墨江金矿床底混合热液改造型矿床。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.