Magnetic properties of airborne particulate matter in Shanghai during dust storm events and the implications for heavy metal contaminant sources     

Peng Qian  Limin Zhou  Xiangmin Zheng  Yan Dong  Yongjie Wang 《Environmental Earth Sciences》2014,72(10):4167-4178

Airborne particulate samples (including dust storm period samples) were collected from the Putuo, Qingpu and Minhang districts of Shanghai city from October, 2009 to October, 2010, and also tracked the dust transporting pathways from NW (Northwest) to SE (Southeast) including the cities of Xi’an, Beijing, Zhengzhou and Nantong, as a means of sampling the dust storm particulate matter in the spring of 2010. After measuring the magnetic parameters and the concentrations of particles and heavy metals, their magnetic properties were analyzed to track the source locations of heavy metal pollution during dust storm events, and then combined for backward trajectory analysis. It was found that the slightly polluted dust particles carried many contaminants during dust storm periods when the dust palls were transported by winter monsoon winds from the NW desert region towards the SE. The contaminants were further increased by contributions of fine SP&SD grains derived from local automobile exhausts in Shanghai as well as being enriched also in Northern cities during non-dust storm periods. A significantly positive linear relation was found between the χ_lf and SIRM of loess and the storm dust, indicating a similar material source for these two kinds of samples. A higher χ_lf and SIRM in storm dust content compared to loess suggests that storm dust contains not only materials from natural sources, but also those from partly anthropogenic sources. Backward trajectory analysis indicates intuitively the source region of the Shanghai storm dust. These conclusions have important scientific significance for research on long-distance transportation of contaminants (such as heavy metals) adsorbed onto airborne particulate matter during dust storm events.  相似文献   

断层输导作用与油气充注作用关系分析   总被引：2，自引：0，他引：2       下载免费PDF全文

刘震  张旺  曹尚  刘明洁  张威  董冬 《地质科学》2014,49(4):1302-1313

断层是控制油气藏形成的重要因素之一;断层的开启及闭合影响到油气运移与聚集的效率。但油气在断层中的运移与在砂层中的充注存在差异性这一问题长期被忽视。一般认为;只要发育断层;其断开的渗透层就会被油气充注;极少关注地层水和石油的压缩特性对充注的影响。本文提出;地下单断层活动时;深部油气在超压作用下以涌流方式难以快速充注进入中浅层被切割的砂体;因此;单砂体至少要存在一条断层作为泄水出口;石油才能通过其余断层充注进入砂体;即单砂体要发育两条及两条以上断层;石油才能注入砂体。在断层静止期;油气通过渗流方式沿特定深度范围断面垂向运移;对油气垂向运移距离影响较小。本文运用4个大型盆地的典型油气藏与断层分布关系讨论了本文观点。该观点对油气成藏规律研究及成藏目标评价有较重要参考意义。  相似文献   

胶东新城金矿床控矿构造变形环境：显微构造和EBSD组构约束   总被引：3，自引：3，他引：0  

李瑞红  刘育  李海林  郑小礼  赵海  孙政 《岩石学报》2014,30(9):2546-2558

新城金矿床是典型的"焦家式"破碎带蚀变岩型金矿,矿体形态和规模都严格受到断裂破碎带控制,是探讨复杂构造-流体耦合成矿系统控矿构造变形环境研究的理想选区。断裂破碎带中构造岩既是构造变形行为的载体,也是相应变形环境的受体。论文在新城金矿详细露头构造解析的基础上,系统采集该矿床控矿断裂破碎带定向构造岩样品,进行显微构造和EBSD组构分析。研究区构造岩显微构造特征主要表现为韧性变形和脆性变形。韧性变形有波状消光、带状消光、亚晶粒、动态重结晶、核幔构造、丝带构造、碎(残)斑系、扭折带、变形纹、机械双晶、蠕英结构、云母鱼等;脆性变形有书斜构造和显微裂隙等。长石(残)斑系、扭折带、变形纹、蠕英结构和石英颗粒边界迁移动态重结晶、丝带构造等矿物变形特征表明断裂带成矿前以高温韧性变形为主;石英波状消光、亚晶粒、亚颗粒旋转和膨凸动态重结晶、方解石机械双晶、长石显微裂隙充填物等矿物变形反映成矿期兼有中低温韧性变形和脆性变形;压剪性穿晶裂隙则反映出成矿后主要是低温脆性变形。根据差应力、应变测量和EBSD组构分析,将新城金矿床控矿构造变形环境可以分为3个构造期:成矿前在NW-SE向挤压作用下发生韧-脆性左行剪切变形,600~700℃,差应力61.37~111.09MPa,应变测量轴比a/c为2.295~3.978,动态重结晶石英颗粒边界分维值为1.466~1.599,反映矿区为高温中高压高应变带变形环境,应变速率较大;成矿期为NW-SE向逐渐NEE-SWW向转变的挤压作用,发生压剪性脆性变形,200~500℃,差应力65.91~135.68MPa,应变测量轴比a/c为1.403~2.204,动态重结晶石英颗粒边界分维值为1.321~1.378,反映矿区成矿期为中低温中高压低应变带变形环境,反应速率较小;成矿后在NWW-SEE向挤压作用下发生压剪变形,150~300℃,反映低温低压脆性变形环境。  相似文献   

太阳活动周与全球大震          下载免费PDF全文

林云芳  林泊宁  陈维升  白志强  郑吉盎  曾小苹 《地球科学》2014,39(12):1857-1863

为研究太阳活动与全球大震的关系, 引入一个无量纲的"地震能量函数√G", 并分析研究了1681—2011故年间全球M≥7.0大震的能量释放的时间序列.由此发现全球大震在太阳活动周4个阶段的分布和活动度, 随震级的强度而异.提出地壳对太阳风暴加卸载响应模式, 用于解释此现象: 通过考察最近331 a, 得出全球共发生了10个M≥9.0超级巨震的时空分布特征, 特别是太阳活动峰年期间没有发生过超级巨震.该研究结果可为判断全球大震提供参考.   相似文献   

云南罗平复杂地层煤矿勘查泥浆体系的研究与应用          下载免费PDF全文

徐铮  陈礼仪  章述  王新华  管强盛  邹杰 《探矿工程》2014,41(3):29-32

云南省曲靖市罗平县红丫口煤矿勘探项目临近大断裂带,受多期构造地质作用影响,走向逆断层发育,且发育有横向平移断层和少量正断层。地层受挤压变形严重,岩层倾角普遍较大,局部直立至倒转,地层破碎。上部漏水严重,下部钻遇多条断层破碎带以及煤系地层,造成钻进效率低下,钻孔事故频繁,甚至钻孔报废,严重影响勘查工作的顺利进行。针对这一系列的施工难题,经过多次研究和反复试验,探索出一种适合该矿区煤矿勘察复杂地层钻进的泥浆,保障了勘查项目的顺利完成。  相似文献   

扬子克拉通东南缘新元古代陆缘弧型TTG的厘定及其构造意义   总被引：4，自引：0，他引：4  

姜杨  赵希林  林寿发  Donald W DAVIS  邢光福  李龙明  段政 《地质学报》2014,88(8):1461-1474

在扬子克拉通东南缘的江山-绍兴结合带沿线多处出露新元古代深成杂岩,以往被认为是沿扬子克拉通和华夏地块碰撞缝合带侵入的板内型深成岩类。本文选择其中的浙江金华罗店中酸性深成杂岩进行了系统的岩石学、年代学和地球化学研究,提出它们属TTG岩石组合,包括英云闪长岩-奥长花岗岩-花岗闪长岩组合(T1T2G1)和二长花岗岩-花岗岩组合(G2QM)两类,普遍以明显富集Rb、Ba、K、Pb等大离子亲石元素而强烈亏损Nb、Ta、Ti、P等高场强元素为特征,δCe为弱负异常或无异常,属典型的弧岩浆岩类。T1T2G1组合富钠贫钾,εNd(t)值=+2.6~+9.4,Mg#值为41.5~63.1,推断由玄武质俯冲板片脱水部分熔融而成,并受到地幔楔橄榄岩熔体的混染。G2QM组合与T1T2G1组合地球化学特征类似,但又明显富K2O(2.75%~5.08%)、LILE和LREE,低Mg#值(27.2~52.31)和εNd(t)值(+1.7~+2.0),应是T1T2G1源区继续部分熔融的产物,可能未受到明显的地幔楔橄榄岩混染。测得花岗闪长岩(G1)锆石SHRIMP U-Pb年龄为841±10Ma,奥长花岗岩(T2)锆石LA-ICPMS U-Pb年龄为793±13Ma,前人报道之花岗岩(G2)年龄为832±44Ma,结合上述地球化学特征,说明T1T2G1和G2QM组合是由新元古代古华南洋向扬子东南缘持续俯冲形成的。综合区域地质资料及前人研究结果,提出金华罗店与诸暨璜山、绍兴平水等地的深成杂岩共同构成了扬子克拉通东南缘一条长达200km的青白口纪(930~793Ma)陆缘弧型深成杂岩带,反映迟至793Ma前仍存在强烈的洋壳俯冲,扬子克拉通尚未与华夏地块发生碰撞拼合,且T1T2G1-G2QM组合的出现指示洋壳俯冲正处于早-中期阶段。  相似文献   

Geochemistry of mafic rocks and melt inclusions and their implications for the heat source of the 14.0°S hydrothermal field,South Mid-Atlantic Ridge     

Bing Li  Xuefa Shi  Yaomin Yang  Jun Ye  Jingjing Gao  Wenqin Zheng 《中国地球化学学报》2014,33(4):325-335

Fresh rocks sampled from the 14.0°S hydrothermal field of the South Atlantic Ridge can be divided into two categories： olivine-gabbro and basalt. The olivine-gabbro is composed mainly of three types of minerals： olivine, clinopyroxene and plagioclase, while a multitude of melt inclusions occur in the plagioclase phenocrysts of the basalts. We analyzed the whole-rock, major and trace elements contents of the basaks, the mineral chemistry of phenocrysts and melt inclusions in the basalts, and the mineral chemistry of olivine-clinopyroxene-plagioclase in the olivine-gabbro, then simulated magma evolution within the crust using the COMAGMAT program. The whole-rock geochemistry shows that all the basalts exhibit typical N-MORB characteristics. In addition, the mineral chemistry characteristics of the olivine-gabbro （low-Fo olivine, low-Mg# clinopyroxene, high-TiO2 clinopyroxene, low-An plagioclase）, show that strong magma differentiation occurred within the crust. Nevertheless, significant discrepancies between those minerals and phenocrysts in the basalts （high-Fo olivine, high-An plagioclase） reflect the heterogeneity of magma differentiation. High Mg# （-~0.72） melt inclusions isobaric partial crystallization simulations suggest that the magma differentiation occurred at the depth shallower than 13.03 km below the seafloor, and both the vertical differentiation column shows distinct discrepancies from that of a steady-state magma chamber. Instead, a series of independent magma intrusions probably occurred within the crust, and their corresponding crystallized bodies, as the primary high-temperature thermal anomalies within the off-axis crust, probably act as the heat source for the development of the 14.0°S hydrothermal system.  相似文献   

Geochemical process of fluorine in soil     

Xiaojing Liu  Binbin Wang  Baoshan Zheng 《中国地球化学学报》2014,33(3):277-279

Fluorine is in the dynamic balance of two geochemical processes, enrichment and leaching, reflecting the adsorption and desorption of fluoride by clay minerals, respectively. The two geochemical processes of fluorine in soil are influenced by factors including geochemical characteristics of soil and clay minerals, pH and sanity of soil solutions, climate, grazing and agriculture activities. Main factors controlling enrichment and leaching process of fluorine in soil can be found with interaction consideration.  相似文献   

吉林省梅河口市张家沟区金矿床成矿地质特征及找矿方向     

王高峰  王政  常玉玺  蒋卫明 《吉林地质》2014,(4)

吉林省梅河口市张家沟区金矿床矿体位于槽台过渡带靠近台区一侧,且基底岩系金丰度值高。区域构造结点有隐爆角砾岩筒存在,岩筒内有硫化物-石英细脉、网脉出现。找矿重点区域应为靠近烟筒桥子一侧的火山角砾岩筒之中。  相似文献   

江苏淤泥质潮滩剖面演变现场观测   总被引：1，自引：0，他引：1       下载免费PDF全文

龚政  靳闯  张长宽  李欢  辛沛 《水科学进展》2014,25(6):880-887

为探究江苏中部沿海双凸型剖面演变特性,在江苏盐城川东港南侧潮间带布设了10个水准观测站,2012年9月至2013年11月对该潮滩剖面演变过程开展了现场观测.结果表明:该潮滩剖面呈现出双凸型特征,平均高、低潮位线附近的滩涂形成淤积率较高的地形凸点;潮间上带受潮流影响小,滩面高程相对稳定;平均高、低潮位之间的区域滩面高程季节性变化明显,总体呈现冲刷状态;潮间下带冲刷显著,滩面坡度增大.全剖面自岸向海呈现"稳定—淤积—稳定—淤积—冲刷"的双凸型剖面特征.  相似文献