矾山磷铁矿床稀土元素地球化学特征

矾山磷铁矿床赋存于矾山杂岩体内 ,呈层状产出 ,是由深源富钾铁镁质岩浆演化而形成的晚期矿床。矾山杂岩体由三期侵入岩和脉岩组成 ,矿床产于第一期侵入岩中。第一期侵入岩较其它期次侵入岩REE含量高 ,按辉石岩—黑云母辉石岩—磷灰石岩的顺序增加。矿床稀土元素地球化学特征及主要元素含量表明 :在岩桨演化晚期 ,在贫硅和缺少足够“Ca2 +”的条件下 ,稀土元素极易代替“Ca2 +”而进入磷灰石晶格形成补尝类质同象。这对于研究矿床形成的物理化学环境和岩桨的演化具有重要意义。     

环境水样中铬形态分析方法研究

研究了水体中几种形态铬的存在状态,分离条件。提出离子交换为主的铬形态分离流程。结合二苯碳酰二肼光度法可测定水样中总铬,溶解态铬,颗粒态铬,六价态铬,无机态和有机态三价铬。已用所拟流程于水样及药物中铬的形态分析,水样加标回收率在９２％－９７％,药物分析结果与标量相符。     

The Origin of the Proterozoic Bidjovagge Gold-Copper Deposit, Finnmark, Northern Norway, as Deduced from Rare Earth Element and Nd Isotopic Evidences on Calcites

Abstract: The Bidjovagge gold-copper deposit, northern Norway occurs in the lower Proterozoic Kautokeino greenstone belt, and consists of ten ore bodies in albite felsite, graphite schist and meta-diabase sills, along with a series of syenodiorite dykes. Calcite is one of the most important gangue minerals occurring within the ore veins. The early primary calcite samples from A, C and D ore bodies (copper–rich) show almost flat chondrite-normalised REE curves, and slightly positive Eu anomalies. A Sm-Nd isotope age of 1858 ± 72 Ma (2ρ) has been given based on fifteen primary calcite samples. The Sm-Nd age of calcite is in well agreement with previously published U-Pb davidite age of 1885 ±18 Ma (2ρ) and Sm-Nd davidite age of 1886 ± 88 Ma (2ρ). All these isotopic age data indicate that the gold-copper mineralisation may occur during or slightly after the peak of the Svecokarelian orogeny. Two late primary calcite samples from C and D ore bodies have flat chondrite-normalised LREE curves, positive HREE curves, and negative Eu anomalies. In contrast, most of the early primary calcite samples from B ore body (gold–rich) show an overall negative chondrite-normalised REE slope and negative Eu anomalies. Sm-Nd data on seven primary calcite samples from the B ore body are relatively scattered, and gave an isochrone age of 1809 ± 150 Ma (2ρ), identical to the age of the calcite samples from A, C and D ore bodies. Two late primary calcite samples from the B ore body have almost flat chondrite-normalised REE slope and negative Eu anomalies. REE patterns and eNd (T) values of calcites suggest that the ore fluids for the calcites from the A, C and D ore bodies derived their metals from mafic igneous rocks (diabase sills). For the secondary calcites from the C ore body, their relative high initial Nd (T) values at 1858 Ma imply that much more radiogenic Nd-component were incorporated during calcite crystallisation when another ore fluid emplaced. Combined Nd isotope data and REE geochemical features suggest that the isotopically more evolved source such as albite felsite and syn-genetic high level syenodiorite dykes were probably metal source for these calcites in the B ore body. Three samples of secondary calcite from the B ore body, which obviously deviated from 1809 Ma isochron are easily explained as products of post-ore hydrothermal events.     

天然水化学组分存在形式的研究理论基础及其应用进展

天然水化学组分存在形式是多种多样的,而在实际的化学分析中,仅给出某化学组分存在形式含量之和,不考虑元素的存在形式,不足以判断天然水组成的控制机理。论述了天然水化学组分存在形式计算的理论基础和方法,并进一步讨论了天然水化学组分存在形式的重要性及其应用进展,指出了这一领域当前存在的问题和今后的研究方向。     

用氢氧化物共沉淀法研究热液体系REE（Nb,Ti）2O6型矿物的形成机理

作者进行了稀土铌钛氢氧化物共沉淀实验,对共沉淀物及其高温灼烧产物进行了XRD、IR、DTA和Raman研究,结合前人高温高压实验结果以及野外地质事实,提出了热液体系复杂氧化物矿物易解石和黑稀金矿的络合物高温水解、氢氧化物共沉淀、脱水去羟、聚合成核和结晶的成因模式。     

东胜煤田侏罗系延安组煤中稀土元素地球化学特征

采用中子活化分析方法（INAA）测定了鄂尔多斯盆地东北部东胜煤田侏罗系延安组煤中稀土元素（REE）的含量,绘制了稀土元素分布类型曲线并计算了多种化学参数.在对REE的地球化学环境和地球化学特征分析的基础上,得出以下结论：①侏罗纪低灰低硫煤中REE的含量较低,且普遍低于华北盆地石炭二叠纪低灰低硫煤中的REE含量.②侏罗纪煤中的REE主要来自于物源区的陆源碎屑.东胜煤田北部靠近物源区,因此REE含量较南部高,且REE含量与灰分产率和SiO2含量有一定的相关性.③侏罗纪煤中REE的分布类型主要取决于母岩.除两个样品外,其他煤样普遍存在Eu负异常,无正Ce异常存在.④与其他岩石相比,煤中REE的分布类型极其复杂,原因在于开放盆地体系的煤中物质不断的改变和再分配.     

Geochemical characteristics of the niobium-rich arfvedsonite granites, Younger Granites province of Nigeria

Arfvedsonite granites are most prevalent in the northern sector of the Nigerian anorogenic ring-complex province wherein they form the main granitic rocks at Kudaru and Fagam and are important components of Kila-Warji, Ririwai and Dutsen-Wai ring-complexes. The albitized variety of these rocks hosts pyrochlore to varying extents depending on the degree of albitization and are, therefore, important targets for niobium investigation. Geochemical data of the granites reveal that niobium has a mean concentration of 111 ppm in the arfvedsonite granite, increasing to 168 ppm in the aegirine arfvedsonite granite and reaching 1568 ppm in the albite arfvedsonite granite. Niobium is thus enriched in the albite arfvedsonite granite by a factor of 8-11 relative to its mean value in the aegirine arfvedsonite and arfvedsonite granites, respectively. Uranium contents show a sympathetic trend with niobium, being also enriched in the albite arfvedsonite granite relative to its abundance in both the aegirine arfvedsonite granite and arfvedsonite granite by a factor of 15. The uranium abundance in the albite arfvedsonite granite is more than 48 times higher than the mean background values in low-calcium granite.The REE fractionation patterns in all three arfvedsonite granite varieties are characterized by enrichment of both the light (La-Sm) and heavy (Gd-Lu) rare earth elements and a significant negative Eu anomaly. The albite arfvedsonite granite is, however, preferentially more enriched in the heavy REE relative to the aegirine arfvedsonite and the arfvedsonite granites. A plot of the ∑REE against Na₂O and niobium reveals positive correlation in the arfvedsonite granites. There is also a linear relationship and strongly positive correlation between Nb and Na₂O because the pyrochlore is most abundant in the most extensively albitized variety of the arfvedsonite granites.     

云南剑川—老君山地区新生代岩浆岩稀土元素特征及构造环境分析

剑川－老君山地区新生代岩浆岩尾轻稀土富集型，各岩类稀土元素标准化配分曲线显示相互平等的特点，稀土含量大致同步变化，表明它们是由地壳硅铝层物质重熔形成的同源岩浆结晶分异而成。岩浆在上侵之前曾发生过分异作用，轻重稀土发生了一定程度的分馏，并导致了铕的轻微亏损。各单元岩石具同源性，岩浆活动发生在板块会聚区造山晚期和造山后阶段。     

庐枞盆地泥河铁矿床中硬石膏微量元素特征、沉淀机制及其对铁成矿作用的制约

泥河铁矿床是长江中下游成矿带庐枞火山岩盆地中典型的磁铁矿-磷灰石型铁矿床。硬石膏是矿床中的主要脉石矿物,在矿床的各个阶段均有发育。本文在详细的野外地质工作和岩相学观察基础上,系统的对矿床各成矿阶段硬石膏开展LA-ICP-MS分析测试工作对硬石膏形成机制进行了分析,初步探讨了硬石膏在铁成矿过程中的作用及意义。矿床中的硬石膏分为三类:与透辉石、磁铁矿、黄铁矿、磷灰石等矿物共生的紫色板状硬石膏(Type Ⅰ);与黄铁矿共生的白色板状硬石膏(Type Ⅱ)以及呈独立脉状产出的白色糖粒状硬石膏(Type Ⅲ)。Type Ⅱ和Type Ⅲ硬石膏REE含量远低于Type Ⅰ硬石膏,Type Ⅱ和Type Ⅲ硬石膏的稀土配分模式相似,二者与Type Ⅰ硬石膏具有很大差别。泥河铁矿床硬石膏中REE含量受结晶学因素的影响较小,主要影响因素为温度、流体的演化过程以及络合物阴离子的类型和数量。早期高温热液中REE主要以Cl络合物形式迁移,矿床中较早沉淀的富稀土矿物捕获了大量REE,使体系中REE含量大幅度减少,致使Type Ⅱ和Type Ⅲ硬石膏稀土含量偏低。晚期流体盐度的降低导致了Cl-/SO42-比值变低,热液中稀土元素的减少以及络合物配位体的改变导致了Type Ⅱ和Type Ⅲ硬石膏稀土配分模式趋于平滑。此外Type Ⅲ硬石膏个别点显示出轻稀土富集的特征,说明热液晚期可能存在硬石膏的溶解再沉淀过程,该过程会改变硬石膏中的稀土配分模式。硬石膏的加入可以提高体系氧逸度,提高热液中铁元素的形成磁铁矿的比率从而利于形成大规模铁矿体。     

珠江口盆地番禺低隆起稀土元素配分模式和重矿物组合特征的分析与应用

利用稀土元素配分模式和重矿物组合特征,结合构造背景、沉积物源分析以及测井、井壁取心等资料,对珠江口盆地番禹低隆起的前古近系基底、珠海组、珠江组下段提出了新的分层方案,这一分层与已有的其他资料符合性更好。分析了研究区内铕、铈异常的特征与原因,认为除了不同物源的影响以外,较强的化学分化作用和沉积时的氧化环境也是造成本区铕、铈异常的直接原因。