长江口吴淞-浏河滨岸带沉积物AVS和SEM含量的空间分布特征   总被引：1，自引：0，他引：1  

孙玮玮  王东启  陈振楼  毕春娟  胡蓓蓓  刘耀龙  李九发  许世远 《地球化学》2009,38(2):140-146

对长江口吴淞-浏河滨岸带37个站位沉积物中酸可挥发性硫化物（AVS）和同时可提取态重金属（SEM）含量及其空间分布特征进行了研究。结果表明,SEM在37个站位沉积物中浓度范围为0．20～1．37μmol／g,平均值为0．74μmol／g;AVS的浓度范围为0．20—0．80μmol／g,平均值为0．23μmol／g;沉积物中AVS含量与总有机碳（TOC）和含水率呈显著正相关关系,而SEM分别与TOC和含水率呈显著正相关关系,与沉积物中值粒径呈显著负相关关系。依据SEM／AVS比值评价方法以及美国EPA（SEM—AVS）差值评价方法对沉积物中重金属的生物有效性的判断表明,除了B2站点无显著生物毒性外,吴淞-浏河滨岸带沉积物中重金属对水生生物均处于中等毒性水平。  相似文献   

He, Ne and Ar isotope compositions of fluid inclusions in hydrothermal sulfides from the TAG hydrothermal field Mid-Atlantic Ridge   总被引：7，自引：2，他引：7  

ZENG ZHIGANG  QIN Yunshan  ZHAI Shikui 《中国科学D辑(英文版)》2001,44(3):221-228

Helium, neon and argon isotope compositions of fluid inclusions have been measured in hydrothermal sulfide samples from the TAG hydrothermal field at the Mid-Atlantic Ridge. Fluid-inclusion³He/⁴He ratios are 2.2—13.3 times the air value (Ra), and with a mean of 7.2 Ra. Comparison with the local vent fluids (³He/⁴He=7.5—8.2 Ra) and mid-ocean ridge basalt values (³He/⁴He=6—11 Ra) shows that the variation range of³He/⁴He ratios from sulfide-hosted fluid inclusions is significantly large. Values for²⁰Ne/²²Ne are from 10.2 to 11.4, which are significantly higher than the atmospheric ratio (9.8). And fluid-inclusion⁴⁰Ar/³⁶Ar ratios range from 287 to 359, which are close to the atmospheric values (295.5). These results indicate that the noble gases of fluid inclusions in hydrothermal sulfides are a mixture of mantle- and seawater-derived noble gases; the partial mantle-derived components of trapped hydrothermal fluids may be from the lower mantle; the helium of fluid inclusions is mainly from upper mantle; and the Ne and Ar components are mainly from seawater.  相似文献   

我国南方早古生代聚煤过程中硫的生物地球化学行为及成矿效应   总被引：1，自引：0，他引：1  

姚素平  丁海  胡凯  焦堃 《地球科学进展》2010,25(2):174-183

我国早古生代煤主要蕴藏在煤炭资源贫乏的南方各省,因坚硬似岩石又称之为石煤,储量极为丰富,仅浙江至广西就分布有长约1 600 km的石煤矿,石煤中含有或富集了多种金属元素,目前已发现的伴生元素达60多种,如钒、钼、磷、钡、镍、铀、金、银等,局部可形成工业矿床而作为某种矿物资源单独开采,是我国有待系统开发的潜在的多矿产资源。研究表明:石煤形成于以菌藻类为主的生物堆积和浅表海或古陆边缘的海相还原环境,含有大量的菌藻类(如蓝绿藻和褐藻)、古孢子、海绵骨针及一些分类尚不明确的原始动、植物等生物化石,具有低碳、高灰、高硫的特点,海相沉积环境和藻类对硫的机械富集与捕集是造成含石煤岩系中硫含量高的主要因素。石煤中富集的金属元素绝大多数是亲硫元素,早期聚煤作用过程是石煤中伴生元素富集的重要阶段,多金属硫化物是石煤中金属元素最重要的赋存形式,主要有硫磺、黄铁矿、黄铜矿、闪锌矿、方硫镍矿、辉镍矿、辉砷镍矿、针镍矿、含镍黄铁矿和硫钼矿等,大量实验及同位素研究资料揭示了细菌还原硫酸盐作用是导致大规模金属硫化物矿化最可能的生物营力,也是石煤和金属硫化物矿床主要的成煤和成矿机制,硫的生物地球化学行为直接影响了金属元素的富集与赋存状态,但早...  相似文献   

市县防震减灾信息服务系统   总被引：1，自引：0，他引：1  

吴微微 《世界地震工程》2011,27(1)

城市防震减灾信息服务系统是面向城市建设、社会管理和灾害应对辅助决策等的多元服务系统,是GIS在震害防御和应急救援体系的综合应用。目前,我国一级城市都建立了比较完善的地震监测预报、地震灾害预防和地震紧急救援三大工作体系,但急剧扩张的市县二三级城市的防震减灾特殊需求却缺少足够重视,其城市震防与公共服务职能也相对滞后。因此,文中阐述了建立市县防震减灾系统的重要意义,分析设计了基于服务器端.Net平台开发的WebGIS应用系统,以实例介绍系统开发过程中的关键问题,最终实现功能完善的市县防震减灾服务系统并通过测试达到预期效果。应用实例表明,该市县防震减灾信息服务系统能满足社会需要和行业需求。  相似文献   

紫金山金铜矿二元铜硫化物成分特点的初步研究   总被引：6，自引：3，他引：3  

刘羽  刘文元  王少怀 《矿床地质》2011,30(4):735-741

文章在电子显微成分分析的基础上,结合XRD、振动光谱等研究手段,对高硫型浅成热液形成的紫金山金铜矿床中铜硫化物的成分、物相特点进行了研究.首次在该区找到了久辉铜矿(Cu1.97S)、雅硫铜矿(Cu1.25S)等铜硫二元组分系列矿物,并发现了铜蓝被蓝辉铜矿明显交代的现象,进而推断它们基本上是同期形成的,但其所处的氧化-还...  相似文献   

两株异化铁还原菌与蒙脱石交互作用实验研究     

曹维政  朱云  鲁安怀  李艳  王清华  张虓雷  王浩然  杨晓雪  王长秋  董海良 《矿物岩石地球化学通报》2011,30(3):311-316

本文选用采自辽宁某矿的天然钠基蒙脱石与两株异化铁还原菌模式菌株Shewanella putrefaciensCN32和She-wanellaoneidensisMR-1,研究了蒙脱石与微生物之间的交互作用。结果表明这两株菌均能还原蒙脱石晶格中的三价铁,使微生物作用于蒙脱石之后的反应体系中二价铁离子浓度明显升高,反应悬浊液颜色由无色变为浅绿色。透射电子显微镜晶格条纹像显示微生物作用后的粘土矿物微结构发生明显变化,其层间距d001值从1.29 nm分别减小为1.06 nm(CN32)和1.02nm(MR-1)。上述结果综合指示这两株异化铁还原菌能够通过还原天然蒙脱石结构中的三价铁促进矿物发生物相转变。  相似文献   

化学激发酸性矿渣粉胶砂性能试验研究          下载免费PDF全文

袁俊航  隆威 《探矿工程》2015,42(8):71-74

以28天最优配方激发酸性矿渣粉为胶凝材料进行试验,分析了质量浓度、灰砂比、减水剂掺量、搅拌时间4个因素对砂浆流动度、失水率、干缩率、抗压强度的影响规律,并且针对灰砂比这一因素将水泥与矿渣粉胶凝材料浆液性能进行了对比。最后选取了合适的比例进行正交试验来优化各因素组合,使砂浆综合性能达到最优。  相似文献   

福建上杭紫金山高硫化型铜矿床矿化分带特征   总被引：3，自引：0，他引：3  

陈可  邱小平  邓俊斌 《福建地质》2013,(4):255-263

通过矿相学,系统分析铜硫化物以及脉石矿物的结构构造、形态特征以及嵌布特征,主要铜硫化物为铜蓝、斜方蓝辉铜矿;通过电子探针,分析铜硫化物各种元素含量,尤其是主量元素Cu/S比值垂向变化规律在钻孔浅部无明显规律,随着深度增加Cu/S比值逐渐减小,最后趋近于一个常数约为1.3。铜矿成矿影响因素:(1)火山机构的温度影响范围有限,并未改变铜硫化物的矿物组合特征,只是影响铜硫化物Cu/S比值分配,表现为越远离火山机构Cu/S比值越高;(2)高氧逸度条件是形成稳定铜硫化物的重要条件。氧逸度垂向由上至下先是具有高氧逸度,随着深度增加氧逸度逐渐减小,最后增加为高氧逸度。Cu/S比值变化规律为今后紫金山铜矿深部找矿提供重要的矿化信息。  相似文献   

The nature and origin of pigments in black opal from Lightning Ridge,New South Wales,Australia     

J. R. Herrmann  R. Maas  P. F. Rey  S. P. Best 《Australian Journal of Earth Sciences》2013,60(7):1027-1039

Abstract

Black opal (opal-AG) owes its dark coloration to a fine-grained pigment commonly inferred to be mainly carbon, yet chemical compositions for black opals suggest there may be additional components. Here we search for such components in pigment concentrates prepared by dissolving black opal nodules (nobbies) from Lightning Ridge (NSW) in hydrofluoric acid, using electron microscopy (scanning electron microscopy, transmission electron microscopy), X-ray diffraction and laser-ablation ICP-MS. The results demonstrate the presence of sulfides—predominantly pyrite and chalcopyrite, with minor galena and Ti-oxide phases, as additional components of the pigment. ATR-FTIR analysis indicates the presence of C=O and C–H groups, consistent with an organic origin. Transmission electron microscopy images of pigment show variously deformed, originally spherical ～100?nm particles rich in sulfide and carbon, which are interpreted as thin coatings of pigment on now dissolved opaline silica spheres. Laser-ablation ICP-MS analysis identifies remnant silica in pigment concentrates, which may be interpreted as opaline silica surviving HF treatment protected as inclusions in sulfides. When examined within the context of petrographic observations from more than 1000 opal nodules (nobbies) at Lightning Ridge, these new results suggest that pigment carbon and sulfides in the nodules formed microbially under initially anoxic groundwater conditions, within pre-existing cavities concurrently being filled with silica sol ultimately derived from chemical weathering of feldspar-rich volcaniclastic sediment. Intensely black pigment layers observed at the floor of many nodules indicate settling of dark, high-density (sulfide–Ti-oxide-rich) pigment within cavities, with the implication that sulfate-reducing bacterial (SRB) activity commences early during the silica sol-gel ripening process. Microbial activity may persist until after the cavity has completely filled with the silica sol, as illustrated by abundant black opals with uniformly distributed pigment. Pigment formed at this stage may no longer be able to settle out within the ripening and increasingly viscous silica gel, thus forming pigmentation throughout the opal cavity. The existence of ‘amber’, pigment-poor opal with intensely black basal pigment layers is interpreted as signalling a lack of sulfate to sustain further SRB activity, or a change to more oxidising conditions, possibly related to interaction with surface waters within a downward-penetrating weathering front. A change in redox conditions would shut off activity of SRB and thus sulfide pigment production and allow development of aerobic microbial activity as described by others.  相似文献   

Hydrothermal Activity Events at Kairei Field,Central Indian Ridge 25°S     

Yejian WANG  Xiqiu HAN  Xianglong JIN  Zhongyan QIU  Zhibang MA  Haili YANG 《Resource Geology》2012,62(2):208-214

The Kairei hydrothermal field is located on the Central Indian Ridge at 70°02′E, 25°19'S, which was discovered in 2000. Eight representative hydrothermal product samples including massive sulfide, sulfide chimney and mineralized rock breccia samples collected from this field were age‐dated using the ²³⁰Th/²³⁴U and ²¹⁰Pb/Pb methods. Four episodes of hydrothermal activity were determined: 94.5 to 96.3 ka (event I), 56.6 to 61.2 ka (event II), 8.4 to 10.6 ka (event III), and <180 a to present (event IV). Among them, event I is the oldest and is characterized by the low‐temperature mineralization of rock breccias which probably represents for the onset of the hydrothermal activity of the field. Events II to IV represent the episodic high‐temperature hydrothermal activities characterized by Cu and Zn‐rich sulfides. The recent hydrothermal activity has lasted for at least 180 a.  相似文献