轻稀土矿城市路尘中重金属含量的粒径分布与空间分异

以典型轻稀土矿尾矿坝附近的工业区和居民区为研究区,首先通过分析不同粒径城市路尘中重金属元素的质量载荷,讨论了路尘中重金属元素含量的粒径分布和空间分异;然后通过主成分分析及稀土特征参数计算,识别了路尘中金属元素的来源。研究结果表明,稀土尾矿坝路尘中重金属元素变异系数较大,空间差异显著,工业区路尘中的金属含量和质量载荷通常高于居民区;重金属元素Cr在8种不同粒径路尘中质量载荷均较大;粒径0.075 mm的路尘中金属质量载荷最大,随路尘粒径增大金属质量载荷显著减小;尾矿坝路尘中重金属元素的主要人为来源是工业源、燃烧源和交通源,主要自然来源是成土母质;稀土元素主要来自于土壤扬尘、矿源以及工业源。     

离子型稀土原地浸矿废弃地中残存稀土分布规律及配分特征

以定南县某原地浸矿废弃地为研究对象,采集不同空间位置、不同深度的土壤样品,分析了废弃地中残存稀土元素的垂直分布规律及稀土配分特征。研究结果显示,废弃地中残存稀土及其配分在矿体内部的空间变异性及空间分布差异性很大,废弃地的腐殖层和残坡积层稀土元素丰度较高,局部区域浓度达1821.54 mg/kg,全风化层稀土丰度受成土母岩与矿层风化程度共同耦合作用影响。对废弃地稀土配分研究分析,发现浸取后残存稀土配分整体上仍呈现分馏效应,且Ce的配分值较未开采原生矿床出现显著增加。对某采样点样品与原生矿床样品对比分析,发现重稀土配分随着深度的增加,在整体上呈现下降的趋势。     

花岗岩中稀土元素的赋存状态及质量平衡研究

本文对花岗岩中稀土元素的赋存状态与质量平衡进行了深入研究,提出应根据岩浆体系成分特征区别对待副矿物和造岩矿物对岩浆演化过程中稀土元素分馏的影响。首次引入描述矿物的蜕晶化程度的物理参数—α衰变辐射剂量D来考查其在地表风化条件下的稳定性,矿物的D值越大、蜕晶作用越强,其抗风能力则越弱,越易在风化条件下分解、释放出稀土离子,极大地控制了花岗岩风化壳的稀土元素配分特征。研究了花岗岩演化过程中的稀土(含稀土)副矿物组合变化特征。     

稀土微肥对苹果中稀土含量的影响

通过连续三年采集稀土微肥实验田和对照区苹果样本,采用电感耦合等离子质谱法测定样品中稀土元素的含量,通过分析发现施加稀土微肥的样品中各稀土元素的含量要略高于对照区的样品,但从三年的连续测定数据来看,又没有递增的趋势。稀土微肥的配分相比,苹果果皮、果肉、果核中铈的配分降低,而土壤中铈的配分有所增高。结果表明,稀土元素在苹果果皮中富集现象明显,与其它稀土元素相比铈元素经叶-茎-根迁移至土壤的速度更快。     

贵州下寒武统黑色页岩稀土元素地球化学特征

研究了贵州开阳、织金等地碳质页岩系岩石化学特征及稀土元素特征.样品中K2O含量大于Na2O,与我国南方类型岩石K2O＞Na2O特征相一致.黑色页岩的稀土元素地球化学特征表明,贵州开阳、织金等地区下寒武统牛蹄塘组黑色岩系中稀土元素总量ΣREE为227.47×10-6～623.18×10-6,黑色页岩系稀土均值为532.69×10-6,其稀土总量偏高.黑色页岩系Y含量范围在122.02×10-6～188.40×10-6,均值为155.26×10-6,反映了富集钇的基本特征.黑色页岩中Dy元素发生一定程度富集.LREE/HREE比值为1.35～1.67,表明黑色页岩系稀土含量组成属于轻重稀土相对集中型.与织金磷块岩稀土组成类似,反映了稀土元素形成具有一定渊源性.稀土组成模式及稀土元素配分模式图表明是较典型的海相沉积物稀土配分模式.综合分析得出本区黑色页岩系属正常海相沉积成因.     

越城岭岩体稀土元素分带特征及其对岩体成因的指示意义

以《湖南省越城岭地区稀有稀散金属矿产调查评价》项目为依托,通过数据对比、图解分析等方法,对该区500余件岩石、土壤样进行统计,分析了不同岩相带、土壤垂直分带中稀土元素含量特征及配分模式,讨论了稀土元素对越城岭岩体成因的指示意义。研究结果表明,越城岭岩体各岩相带内稀土元素含量具有明显的差异性,且分带性明显;土壤中稀土相对岩石更富集;该区稀土元素曲线配分右倾;轻稀土相对重稀土较富集;普遍具Eu中等负异常;稀土元素特征指示该岩体具有重熔型花岗岩的特征。     

河南卢氏官坡—五里川锑矿带稀土元素特征及与成矿的关系

为了研究河南省卢氏县官坡—五里川锑成矿带成矿机制,对其稀土元素地球化学特征进行分析。锑矿带内锑矿石及其他类型岩石轻、重稀土元素比值较高,且都呈现为Eu负异常,稀土元素配分模式总体上表现为轻稀土富集型。锑矿带内各种类型岩(矿)石中稀土总量分布表现出一定规律性,大理岩、锑矿石中稀土元素总量较高,构造带岩石及附近围岩的稀土元素总量偏低,说明锑矿带的锑及成矿热液主要来自于下地壳和上地幔,热液上升过程中锑矿床经历了多阶段的分馏、交代作用,导致稀土元素从围岩中大量迁出,并富集于锑矿床内。     

钢铁中稀土总量和轻重稀土分量的测定

随着稀土在冶金中应用的发展,要求有相应的稀土总量与轻重稀土分量的测定方法。 我国稀土资源丰富,矿源轻重比例各不相同,这就反映到加入钢铁中的稀土元素轻重比例也各不相同。尽管以前测定稀土总量的灵敏显色剂很多,但大多数对轻稀土的发色能力强、摩尔吸光系数较大;而对重稀土含量高的样品,测其总量就存在着因轻重稀土比例不同而检量线不同的问题。     

冀东-辽西金矿床稀土元素特征及其成矿作用探析

针对冀东-辽西主要金矿床成矿地质特征的差异性,选取了金厂峪、峪耳崖、二道沟和排山楼金矿20件金矿石样品的稀土元素和微量元素测试分析数据,其稀土配分模式图整体右倾-轻稀土富集型,显示了相似的成矿物质来源,Au-Bi的紧密相关性表明形成于中高温热液环境,部分样品稀土配分曲线的反倾和跳跃反映了该区矿床多因复成的特点,且稀土总量随金矿化的增强而逐步降低,可作为一种新的含矿性评价指标。     

广东和寮铅锌矿稀土元素地球化学特征及其地质意义

对广东和寮铅锌矿不同岩石样品进行稀土元素地球化学特征的测试对比分析,结果表明,四种岩石样品稀土元素总量存在差异,矿石稀土元素总量介于混合岩和大理岩之间,且更接近于这两种岩石,表明了铅锌矿的形成与混合岩和大理岩关系可能更为密切;铅锌矿矿石的稀土元素配分模式曲线与混合岩和大理岩极为相近,轻重稀土的富集程度介于混合岩和大理岩之间,这也反映了区内铅锌矿的形成与混合岩和大理岩有着密切的关系;混合岩和大理岩为铅锌矿的主要矿源层,在混合岩化作用形成混合岩的过程中,混合岩化作用产生的热液与围岩大理岩发生反应,生成了富含铅锌矿的矿石。所以,在研究区今后进行矿产勘查时,应更加关注混合岩和大理岩的接触地段。     

Geochemistry of rare earth elements in cobalt-rich crusts from the Mid-Pacific M seamount

Rare earth elements (REEs) and major elements of 25 cobalt-rich crusts obtained from different depths of Mid-Pacific M seamount were analyzed using inductively coupled plasma-atomic emission spectrometer and gravimetric method. The results showed that they were hydrogenous crusts with average ∑REE content of 2084.69 μg/g and the light REE (LREE)/heavy REE (HREE) ratio of 4.84. The shale-normalized REE patterns showed positive Ce anomalies. The total content of strictly trivalent REEs increased with water depth. The Ce content and LREE/HREE ratios in Fe-Mn crusts above 2000 m were lower than those below 2000 m. The change in REE with water depth could be explained by two processes: adsorptive scavenging by setting matters and behaviors of REE in seawater. However, the Ce abundance took no obvious correlation with water depth reflects the constant Ce flux. The Ce in crusts existed mainly as Ce(IV), implying that the oxidative-enriching process was controlled by kinetic factors.     

Geochemical Characteristics and Significance of Major Elements, Trace Elements and REE in Mineralized Altered Rocks of Large-Scale Tsagaan Suvarga Cu-Mo Porphyry Deposit in Mongolia

The alteration types of the large-scale Tsagaan Suvarga Cu-Mo porphyry deposit mostly comprise stockwork silicification, argillization, quartz-sericite alteration, K-silicate alteration, and propylitization. The mineralized and altered zones from hydrothermal metallogenic center to the outside successively are Cu-bearing stockwork silicification zone, Cu-beating argillized zone, Cu-Mo-bearing quartz-sericite alteration zone, Cu-Mo-bearing K-silicate alteration zone, and pro- pylitization zone. The K-silicate alteration occurred in the early phase, quartz-sericite alteration in the medium phase, and argillization and carbonatization （calcite） in the later phase. Ore-bearing-altered rocks are significantly controlled by the structure and fissure zones of different scales, and NE- and NW-trending fissure zones could probably be the migration pathways of the porphyry hydrothermal system. Results in this study indicated that the less the concentrations of REE, LREE, and HREE and the more the extensive fractionation between LREE and HREE, the closer it is to the center circulatory hydrothermal ore-forming and the more extensive silicification. The exponential relationship between the fractionation of LREE and HREE and the intensity of silicification and K-silicate alteration was found in the Cu-Mo deposit studied. The negative Eu anomaly, normal Eu, positive Eu anomaly and obviously positive Eu anomaly are coincident with the enhancement of Na2O and K2O concentrations gradually, which indicated that Eu anomaly would be significantly controlled by the alkaline metasomatism of the circulatory hydrothermal ore-forming system. Therefore, such characteristics as the positive Eu anomaly, the obvious fractionation between LREE and HREE and their related special alteration lithofacies are suggested to be metallogenic prognostic and exploration indications for Tsagaan Suvarga-style porphyry Cu-Mo deposits in Mongolia and China.     

Accumulation and Fractionation of Rare Earth Elements in Soil-Rice Systems

Rare earth elements(REEs)have been widelyapplied in agriculture as micro-fertilizer in China,andit has become an urgent taskto understand their cont-ents,distribution,translocation and accumulation inthe soil-crop systems and their ecological effects,inor…     

西华山钨矿床流体包裹体的稀土和微量元素特征

为探讨西华山钨矿床流体的稀土元素和微量元素特征,明确热液和成矿物质的来源,揭示成矿流体性质,采用高精度电感耦合等离子质谱（ICP—MS）方法对该矿石英脉流体包裹体的微量和稀土元素进行了分析测试。结果表明,流体包裹体中稀土元素总量变化大,主要表现为轻稀土富集,轻、重稀土内部分异程度不均一,轻稀土分馏程度明显大于重稀土分馏程度;δEu变化范围比较大,大部分样品表现为δEu的负异常;微量元素之间的比值反映出西华山钨矿床成矿物质从深源到浅源,主要来源于岩浆,同时又有少部分来源于大气水循环作用淋滤围岩地层所产生的矿物质,成矿流体处于流体演化的晚期热液低温阶段。     

Distribution of rare earth elements in sewage-irrigated soil profiles in Tianjin, China

The concentrations of rare earth elements(REEs)in the soil extracts and soil solutions from two different alluvial soil profiles irrigated with sewage were measured using inductively coupled plasma-mass spectrometry.The results showed that the REE concentrations in the soil extracts from soil samples affected by sewage irrigation were much higher than those in virgin soil samples.The REE concentrations in the soil extracts of the rhizophere soil were higher than those of the non-rhizophere soil.The shale-normalized REE patterns in the soil extracts from the upper soil layer affected by sewage irrigation shown middle REE(MREE)enrichment relative to light REE(LREE)and heavy REE(HREE).This result was attributed to the MREE-rich organic colloidal material,REE-HM(humic and fulvic acids)and phosphate-REE complexations.The REE patterns in the soil extracts from deep soil little-affected by sewage irrigation showed HREE enrichment relative to LREE,which might have been caused by the preferential complexation of HREE with carbonate.The normalized La/Yb ratios in the soil extracts increased with the decrease in depth.The sewage irrigation did not affect the total REE contents and REE pattern in the soil profiles.     

REEs fractionation and sedimentary implication in surface sediments from eastern South China Sea

To get features of rare earth elements(REEs)fractionation,106 surface sediment samples from eastern South China Sea were determined for REEs combined with major and trace elements by ICP-MS.The distribution pattern of REEs,strong correlation between REEs and Al,North American shale composite(NASC)normalization all suggest a dominant crustal source for REEs in the research area.However, distinct fractionation among REEs was observed in surface sediment from area with water depth over 2000 m,confirmed by the strong positive correlation among light rare earth elements(LREEs)and among heavy rare earth elements(HREEs)but weaker relationship between LREEs and HREEs.Eluviation by Cl – might be a key role on the fractionation of REEs,comparing with factors such as grain size,co-precipitation with Fe and Mn hydroxide,calcareous and siliceous biogenic precipitation.The fractionation among REEs could be used as index to illustrate the sedimentary environment in reverse.     

Geochemical Study of Rare Earth Elements on Four Attapulgite Clay Deposits in Jiangsu and Anhui Provinces, China

This paper discussed in detail about the BEE component and the characteristics of the different kinds of attapulgite clay ores as well as basalts, weathered basalts in four localities of attapulgite clay deposits of Jiangsu and Anhui Provinces of China. It is concluded that the half-weathered basalts have not distinct REE fractionation and strong weathered basalts have HREE loss in the process of the basalts weathered to form smectite group minerals. And the latefitic montmorillonite clays that formed from the basalts weathering have a distinct Ce positive anomaly, a little MREE loss and LREE and HREE renew enrichment. That reflects the particular oxidation condition in the Earth‘‘ s surface and the adsorption of the colloid solution of the lake water in the basin of the continent in the time of the clays formed. The attapulgite clays produced by the reaction between basahs with lake water in the original place of the basin have same REE characteristics as that of the basalts and the weathered basahs. This shows that REE does not transfer heavily in the progressive chemical weathering process. The sedimentary attapulgite clays have also a similar REE component and characteristic parameters to the basalts and the weathered basalts, and have a distinct Eu negative anomaly and a big value of LREE/HREE, which shows that the sedimentary clay came from the weathered basalts, and BEE partitioning patterns characters of the clays are controlled by the residual material of the weathered basalts.     

乌云盆地林海花岗岩体地球化学特征及其与成矿的关系

通过对乌云盆地林海花岗岩体地质地球化学特征的调查研究,认为它是印支期岩浆活动形成的岩体,岩石类型为二长花岗岩。岩体SiO₂ 含量为68.17%~76.23%、Al₂O₃ 含量为12.41%~14.41%、Na₂O+K₂O 为9.24~10.98、K₂O/Na₂O 为1.65~2.14、A/CNK 介于0.923~0.965 之间。ΣREE 为55.26×10^-6~88.02×10^-6,总量偏低;LREE/HREE 为2.71~10.27;Eu 为0.28~0.32;δCe 为0.81~0.91;（La/Yb）N为1.79~11.12,轻稀土富集、铕亏损、铈富集且轻重稀土分馏较明显。过渡元素原始地幔标准化蛛网图曲线总体呈“W”型。研究表明,乌云盆地二长花岗岩属低铝高钾亚碱性I 型花岗岩,形成于后造山拉张性大地构造环境,形成深度为地壳,形成位置是板块内部。     

Diffusion Wave Model for Simulating Storm-Water Runoff on Highway Pavement Surfaces at Superelevation Transition

On a curved section of highway, the cross slope of the road is often designed to be superelevated to balance the centrifugal force and gravity applied on vehicles. The accumulation of storm-water runoff (sheet flow) near superelevation transitions may significantly increase due to the extended flow path and converging flow lines. A two-dimensional finite-volume-based diffusion wave model is developed to simulate the sheet flow on these geometrically complex surfaces. Both Dirichlet- and Neumann-type boundary conditions are developed for open boundaries based on kinematic wave theory. Results show that the distribution of sheet flow is closely related to the cross slope, longitudinal slope, rainfall intensity, and the width of the road. The analysis of sheet flow characteristics on superelevation transition areas suggests that the optimal longitudinal slope in the range of 0.3–0.4% minimizes the depth of storm-water runoff on the road surface.     

Rare earth elements in tropical surface water,soil and sediments of the Terengganu River Basin,Malaysia

The 14 stable rare earth element(REE) concentrations and distribution patterns were investigated for surface waters(n=51),soils(n=52) and sediments(n=42) from the tropical Terengganu River basin,Malaysia.The chondrite normalized REE patterns of soils developed on four geological units showed enrichment of LREE,a pronounced negative Eu,and depletion of HREE with an enrichment order granite>>metasedimentary>alluvium>volcanic.The REE patterns in sediments reflected the soil REE patterns with an overall order o...