痕量金属孔隙水取样技术比较

痕量金属孔隙水取样技术比较ＳｔｅｖｅｎＥ．ＢｕｆｌａｐＨｅｒｂｅｒｔＥ．Ａｌｅｎ刘新华译王洪艳校采集和分析孔隙水已经成为许多环境计划的一个重要方面，并且已用于化学物质在水体中扩散的研究。因此了解孔隙水化学物质的浓度，在沉积物污染估价和沉积物对水体表面...     

美国蒙大拿州朱迪斯山碱性侵入岩特征与吉斯金—银碲化物…

蒙大拿州朱迪斯山吉斯金－银碲化物矿床产生晚白垩世到古新世碱性斑岩侵入体与中寒武世到晚古新世沉积岩之间的接触带附近，呈陡倾斜石英脉，微量元素地球化学表明，这些侵入体可能来源于正在俯冲的缓倾斜费拉隆重板块岩石圈或上覆的软流圈地幔。吉斯矿床的脉矿化可分为四个阶段，主要矿物组合是：Ｉ．石英－黄铁矿－钒云母－碳酸盐；Ⅱ．石英－黄铁矿－贱金属硫化物－碳酸盐－少量碲化物－钒云母；Ⅲ石英－碲化物－黄铁矿－钒云母－     

河南鲁山太华群两类斜长角闪岩地球化学对比及其构造环境

河南鲁山早前寒武纪太华群中分布着两类斜长角闪岩：一类为正常斜长角闪岩,主要产于晚太古代下太华群荡泽河组;另一类为富钠斜长角闪岩,产于古元古代上太华群雪花沟组。两类岩石外表特征和矿物成分相近似,但化学成分明显不同。正常斜长角闪岩具较低的Na2O（1．96％－2．86％）、K2O（0．24％－0．64％）、Ti、Y、Zr、Hf和REE含量,而富钠的斜长角闪岩以较高的Na2O（3．31％－5．50％）、K2O（0．47％－1．41％）、Ti、Y、Zr、Hf和REE含量为特征。通过对比研究,认为前者为拉斑玄武岩,成分与现代洋壳中发现的低钾拉斑玄武岩相似;后者主要为富钠的基性火山岩,与陆内裂谷或地槽区产出的细碧岩相似,表明本区Pt／Ar转变过程中的构造环境发生了重大变化。这一转变过程初步认为是本区晚太古代地壳上升所引起的长期风化剥蚀作用的结果。     

余震：是地震,还是多余物？

我们易于把余震看成在科学和社会方面均不重要的多余物。新闻媒介常这样向地震学家发问:“这只是一次余震吗?”“只是”两字意味着余震几乎不被关心。地震学家自己也常忽略那些紧跟着大地震之后发生的事件的重要性。即使是足够大的余震,     

Fine sediment and nutrient dynamics related to particle size and floc formation in a Burdekin River flood plume, Australia

The extreme 2010-2011 wet season resulted in highly elevated Burdekin River discharge into the Great Barrier Reef lagoon for a period of 200 days, resulting in a large flood plume extending >50km offshore and >100km north during peak conditions. Export of suspended sediment was dominated by clay and fine silt fractions and most sediment initially settled within ～10km of the river mouth. Biologically-mediated flocculation of these particles enhanced deposition in the initial low salinity zone. Fine silt and clay particles and nutrients remaining in suspension, were carried as far as 100km northward from the mouth, binding with planktonic and transparent exopolymer particulate matter to form large floc aggregates (muddy marine snow). These aggregates, due to their sticky nature, likely pose a risk to benthic organisms e.g. coral and seagrass through smothering, and also by contributing to increased turbidity during wind-induced resuspension events.     

花岗质岩石新地球化学分类介绍及有关问题评述

Frost等主要依据花岗岩类常量元素分析,考虑铁镁指数,修改的碱钙指数(MALI)和铝饱和指数三个参数,将花岗岩类岩石划分为16个成分组,即16种类型。该分类方案能对岩浆来源和大地构造背景提供信息,基本上保留了以前一些花岗岩分类方案的最佳品质。本文对这个分类方案进行了详细介绍,并对各种花岗岩类分类方案进行了简要评述。     

Utilizing gamma isotope tracers to determine sediment source at reef sites near the Charleston Ocean Dredged Material Disposal Site

The Charleston, South Carolina Ocean Dredged Material Disposal Site (ODMDS) has been heavily utilized as a disposal site for dredged material resulting from maintenance and channel deepening in the Charleston Harbor. Continuous monitoring by the South Carolina Department of Natural Resources at the ODMDS has indicated the presence of fine-grained sediment within the monitoring zones. However, since the Charleston Harbor is formed by the conjunction of three rivers, it has been suggested that some of the fine-grained sediment surrounding the ODMDS could be due to river transport rather than solely by disposal activities. In order to trace the outflow of sediment from the harbor, natural and man-made isotopes were utilized. (7)Be (natural cosmogenic isotope) and (137)Cs (man-made isotope) are often associated with estuarine sediments. Both isotopes were used as tracers in an attempt to determine the extent of density driven sediment flow from the Charleston Harbor. (7)Be was detected in many of the offshore sampling stations indicating a direct correlation to the harbor. (137)Cs was only found in one sediment trap sample offshore, but none the less indicated some transport from the harbor. Further study for utilizing isotopic tracers in determining offshore sediment transport is still being conducted at the disposal site. It is anticipated that further (7)Be and (137)Cs isotopic monitoring offshore Charleston will aid in determining the role that tidal and density driven sediments play in the sediment budgets at the hard bottom reef sites.     

新墨西哥州林肯县诺加尔矿区与碱性岩有关的成矿作用

已知沿落基山最东边缘的碱性岩内赋存许多种矿床，包括大型金矿床（〉１，０００，０００盎司）。新墨西哥州林肯县有１１个这样的碱性岩中心，其中最大的碱性岩中心赋存诺加尔矿区的各种矿床。该矿区位于新墨西哥中－南部谢拉布兰卡山，矿床分４种类型：（１）含Ａｕ矿脉和角砾岩；（２）Ａｇ－Ｐｂ－Ｚｎ矿脉；（３）Ｍｏ－Ｃｕ矿点；（４）砂金矿。矿区岩石以安山岩流和塑流角砾岩占优势，有３个浅成碱性岩株侵入其中。本文通过对     

海南岛西南几个金矿床成矿流体与稳定同位素地球化学

二甲、抱板、不磨三个金矿床位于海南岛西部，沿北东向戈枕断裂带分布，含金脉体产于中元古代抱板群中，受韧性剪切带控制。其成矿流体是中温（２５０－３５０℃）、低盐度（４ｗｔ％－１０ｗｔ％Ｎａｃｌ）、较富ＣＯ２＋ＣＨ４的流体，氢、氧、硫同位素研究证明主要为变质－混合岩化热液矿床，成矿物质大多来自抱板群矿源层。雅亮伴生金矿位于海南岛南部，沿东西向九所－陵水深断裂分布，同位素研究表明该矿床为一低温（１５０－２