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1.
西藏隆子县恰嘎锑矿床流体包裹体及H、O、S同位素组成特征 总被引：1，自引：0，他引：1
西藏隆子县恰嘎锑矿位于藏南喜马拉雅特提斯造山带的中东部,属藏南江孜-隆子金锑多金属成矿带。综合研究该矿床的石英流体包裹体特征和H-O-S同位素的组成,发现其流体成矿过程包括:黄铁矿-石英阶段发育富液相包裹体(W型),均一温度集中在170～180℃,盐度w(NaCleq)为2.86%～7.17%,成矿压力平均为47.15MPa,成矿深度平均为1.57 km;石英-硫化物阶段主要发育富液相包裹体(W型),其次为CO2-H2O三相包裹体(C型),均一温度位于200～220℃区间,盐度w(NaCleq)为2.20%～5.11%,成矿压力平均为47.46 MPa,成矿深度平均为1.58 km。矿区总体上流体属含微量CO2气体的中低温、低盐度的NaCl-H2O热液体系。H-O和S同位素结果表明存在地幔流体参与成矿,其赋矿浅变质沉积岩地层也为成矿提供了部分成矿流体,以上研究证明,恰嘎锑矿属于多来源流体浅层中低温矿床。 相似文献
2.
云南南秧田钨矿床流体包裹体特征及其意义 总被引：3，自引：0，他引：3
对南秧田矽卡岩型钨矿床的石英和石榴石流体包裹体的岩相学特征研究表明,与成矿有关的包裹体主要有3类:富液相、富气相和含子晶的多相包裹体。石英包裹体均一温度范围为232～337℃,盐度w(NaCl)=0.53%～9.98%;石榴石包裹体的均一温度范围为228～306℃,盐度w(NaCl)=6.45%～14.04%。激光拉曼探针分析表明,南秧田白钨矿的成矿流体中气相成分以H2O为主,含少量CO2、CH4、H2S和N2等气体,液相成分以H2O为主,属NaCl-H2O流体体系。成矿溶液的密度为0.72～0.87g/cm3,表明形成这种矽卡岩型矿床的成矿流体均属于中温、低盐度、低密度的流体。成矿压力为18～32MPa,成矿深度约为0.6～1.2km。石英包裹体水的δD为-72.16‰～-65.10‰,δ18O为7.98‰～8.45‰,钨矿床中硫化物δ34S为6.6‰。成矿流体主要来自燕山晚期的岩浆热液作用。 相似文献
3.
新疆萨热阔布金矿床流体包裹体研究及矿床成因 总被引：2，自引：0，他引：2
新疆萨热阔布金矿床位于阿尔泰造山带南缘克兰火山-沉积盆地内,矿体呈脉状产于康布铁堡组上亚组地层中(D1k2)。不同成矿阶段石英脉中广泛发育流体包裹体,可划分为H2O-CO2包裹体(C型)、纯CO2包裹体(PC型)、水溶液包裹体(W型)及含子矿物多相包裹体(S型)四类。测温结果显示,成矿早阶段主要发育C型和PC型包裹体,均一温度范围为271～446℃,流体盐度介于5.9%～8.4%NaCleqv之间;中阶段主要发育C、PC、W和S型包裹体,均一温度低于早阶段,为236～374℃,流体盐度介于4.8%～15.0%NaCleqv之间;晚阶段主要发育W型包裹体,均一温度范围为139～264℃,流体盐度介于1.1%～6.9%NaCleqv之间。对成矿压力和深度的估算表明,成矿压力为90～330MPa,成矿深度为9～12km。综上所述,萨热阔布金矿成矿流体具有富CO2、中低盐度的变质流体特征,流体沸腾导致了成矿物质的沉淀。结合矿床地质特征,萨热阔布金矿床属于造山型金矿床。 相似文献
4.
对南秧田层状矽卡岩型白钨矿石中石榴石及电气石石英脉型白钨矿石中石英流体包裹体岩相学特征研究表明,与成矿有关的包裹体主要有富液相、富气相和含子晶的流体包裹体3种类型.矽卡岩型矿石中石榴石及共生石英的包裹体均一温度为128～250℃,盐度w(NaCl) =0.7％ ～8.1％;电气石石英脉型白钨矿石中石英的流体包裹体均一温度范围为181～ 325℃,盐度w(NaCl)=1.57％ ～ 15.76％.两种类型矿石成矿溶液密度为0.75～0.95g/cm3,表明形成这两种类型矿石的成矿流体均属于中温、中-低盐度、低密度的流体.氢氧同位素结果显示其主要来源于地层水(变质水),后期受到了岩浆水的叠加改造作用.硫同位素落入沉积岩、变质岩及蒸发硫酸盐的硫同位素组成范围内. 相似文献
5.
综合研究广西栗木矿田香粉厂、老虎头、牛栏岭、金竹源矿床矿石中的石英流体包裹体,结果表明,成矿热液矿物中的原生流体包裹体类型主要为纯液相包裹体,其次为气液两相包裹体。香粉厂矿床流体包裹体的均一温度平均值为203.5℃,盐度为5.54wt%NaCl,密度0.885g/cm3,压力为55.31MPa,成矿深度为5.94km;老虎头矿床流体包裹体的均一温度平均值为168℃,盐度为6.50wt%NaCl,密度0.934g/cm3,压力为46.72MPa,成矿深度为5.42km;牛栏岭矿床流体包裹体的均一温度平均值为187℃,盐度为5.03wt%NaCl,密度0.919g/cm3,压力为46.00MPa,成矿深度为5.37km;金竹源矿床流体包裹体的均一温度平均值为178℃,盐度为5.54wt%NaCl,密度0.913g/cm3,压力为48.42MPa,成矿深度为5.51km,总体属中低温度、低盐度、中等密度的体系;表明该矿床形成于中深成环境。 相似文献
6.
云南哈播斑岩铜(-钼-金)矿床流体包裹体研究 总被引：3，自引：3，他引：0
哈播斑岩Cu-(Mo-Au)矿床产于哀牢山富碱斑岩带的南段,形成于青藏高原后碰撞阶段构造转换环境,属于陆-陆碰撞型斑岩矿床.根据脉体的交切关系,确定哈播矿床各种脉的演化序列为早期石英脉→石英-黄铜矿脉→石英辉钼矿脉.脉中流体包裹体的岩相学、显微测温和激光拉曼光谱分析等研究结果显示,各期脉中均有富气相包裹体、富液相包裹体和含子矿物多相包裹体,各种包裹体的气相均含有CO2、SO2、H2O等气体.各期脉中多种包裹体并存并具有相似的均一温度范围,富液相包裹体均一温度149～427℃,盐度ω(NaCleq)6.0％～15.0％;富气相包裹体均一温度205～405℃,盐度ω(NaCleq) 3.4％～19.0％;含子矿物多相包裹体均一温度305～516℃,盐度w(NaCleq) 33.5％～61.0％.哈播矿床的初始成矿流体由稳定共存、不混溶的低盐度流体和高盐度流体组成,高盐度流体是哈播矿床成矿元素迁移的主要载体.成矿流体在400℃左右发生“二次沸腾”、分相,温度下降和挥发分持续逃逸可能是Cu-Au成矿的诱因.Mo元素在成矿流体多次沸腾、分相过程中,持续优先分配进入高盐度流体中而逐步富集;温度下降,使含钼硫化物在流体中溶解度降低、沉淀,形成石英-辉钼矿±黄铜矿脉. 相似文献
7.
北京万庄金矿床流体包裹体研究 总被引：2，自引：0，他引：2
对北京万庄金矿床流体包裹体的研究发现,同一石英样品中原生流体包裹体的均一温度存在三个明显不同的温度区间,即90.8～169.7,276.8～298.8,335.2～376.4°C,各温度区间对应流体的平均盐度w(NaCl)分别为4.39%,7.13%,12.83%,流体包裹体温度和盐度的特点反映在石英生长过程中捕获了不同来源的流体;稳定同位素的研究结果表明,前、后两种流体分别代表了大气降水和岩浆水的特点,中间为两者的混合体,说明万庄金矿床在成矿过程中有大气水和岩浆水两种流体的参与;利用流体包裹体特征,计算出成矿压力,由压力值估算成矿深度为2.00～2.42 km,从而确定该矿床属造山型金矿床中的浅成金矿床. 相似文献
8.
哈图金矿床位于新疆北部准噶尔盆地西缘哈图断裂和安齐断裂夹持的狭长地带中。矿床受安齐断裂及其周围伴生的次一级断裂的控制,主要产出石英脉型和蚀变岩型2种金矿体。根据矿物共生关系和脉体穿插关系,将哈图金矿床从早到晚划分为3个成矿阶段。石英脉流体包裹体研究显示,矿体存在3种类型的流体包裹体,分别为Ⅰ型:富液相L+V两相包裹体;Ⅱ型:富气相L+V两相包裹体;Ⅲ型:CO2-H2O型三相包裹体。早阶段发育Ⅰ型、Ⅱ型和Ⅲ型包裹体,均一温度293～379℃,流体盐度为1.0%～5.7%。中(主)阶段发育Ⅰ型、Ⅱ型和Ⅲ型包裹体,均一温度213～291℃,流体盐度为0.5%～5.9%。晚阶段只发育Ⅰ型包裹体,均一温度148～216℃,流体盐度为1.4%～4.0%。经过压力和深度计算,成矿压力为49～97 MPa,对应深度在4.8～9.4 km。根据哈图金矿石英的δ18OV-SMOW值为20.4‰～21‰,计算得到平衡水的δ18OH2O值在8.6‰～14.7‰,同时测得石英包裹体水的δ18DH2O为-77.2‰～-64.5‰。和前人研究结果对比,认为哈图金矿床为造山型中-低温热液金矿床,成矿流体是以大气降水为主体受岩浆和变质影响的低盐度CO2-H2O体系。 相似文献
9.
一六钨矿大地构造位置位于南岭成矿带中段南缘,粤北曲仁盆地西南缘,是粤北地区近年来重要的找矿勘查成果之一。矿床为典型的矽卡岩矿床,矿体赋存于上泥盆统帽子峰组矽卡岩以及NWW向钾长石-石英-白钨矿脉和云母石英脉中。通过野外观察和镜下研究,本文将成矿过程分为矽卡岩期(A)和热液期(B),矽卡岩期可以分为早期矽卡岩阶段(A1)、晚期矽卡岩阶段(A2)、钾长石英白钨矿阶段(A3),热液期可以分为云母石英脉阶段(B1)和石英碳酸盐阶段(B2)。矿区包含4种类型的包裹体:含子矿物三相包裹体(Ⅰ型)、气液两相水溶液包裹体(Ⅱ型)、CO_2水溶液三相包裹体(Ⅲ型)、纯CO_2包裹体(Ⅳ型),Ⅰ型包裹体仅见于A3阶段;Ⅱ型、Ⅲ型以及Ⅳ型包裹体在A3和B1阶段石英中均有发育,在A3和B1阶段白钨矿中还发育Ⅱ型包裹体。A3阶段Ⅰ型包裹体完全均一温度为162~381℃,盐度为30.1%~45.4%(wt%NaClequiv,下同省略),Ⅱ型包裹体完全均一温度为154~363℃,盐度为1.49%~11.0%,Ⅲ型包裹体完全均一温度为290~390℃,盐度为2.20%~6.88%;B1阶段Ⅱ型包裹体完全均一温度为152~381℃,盐度为1.65%~9.32%,Ⅲ型包裹体完全均一温度为281~378℃,盐度为2.00%~8.82%。激光拉曼探针分析表明,A3阶段和B1阶段流体中存在H_2O、CO_2、CH_4和少量CO_3~(2-),指示流体处于还原的环境。包裹体完全均一温度—盐度关系图表明,数据点主要集中于三个区域:a区对应早期出溶成因的高盐度流体,b区反映流体发生了不混溶作用,c区反映早期高盐度流体与低盐度地下水混合特征。各区包裹体代表了岩浆期后残余原始流体不同阶段的演化产物。通过Ⅰ型包裹体计算得出的成矿压力范围为86.0~415.8MPa,用Ⅱ、Ⅳ型包裹体对成矿压力进行校正得出,A3阶段成矿压力范围为86~115MPa,成矿温度为176~279℃;B1阶段成矿压力范围为55~93 MPa,成矿温度为160~228℃,估算成矿深度范围为3.62~4.26km。研究认为,流体在演化早期存在局部高压,流体不混溶作用要比外来流体混入更早发生,而流体混入促进了流体的不混溶作用。流体物理化学条件的改变、外来流体混入以及流体不混溶作用是引起钨矿沉淀的主要原因。 相似文献
10.
南岭东段岩前矽卡岩型钨矿成矿流体研究 总被引：3，自引：0，他引：3
南岭东段以石英脉型钨矿集中产出而闻名于世,岩前钨矿是该地区新近发现的中型矽卡岩型钨矿。本文在详细矿床地质和成矿期次研究基础上,对矽卡岩型矿体各成矿阶段的代表性矿物石榴子石、白钨矿、石英、方解石及矽卡岩附近白钨矿 黑钨矿石英脉中石英的流体包裹体进行了系统的岩相学、显微测温、激光拉曼光谱分析和氢氧同位素地球化学研究。岩前钨矿流体包裹体类型主要为富液相两相水溶液I型包裹体和含CO2三相水溶液Ⅳ型包裹体,石榴子石和石英中I型包裹体中偶见子晶。白钨矿 黑钨矿石英脉中的石英相比矽卡岩型矿体中的石英具有更多的Ⅳ型包裹体。早期矽卡岩阶段的流体参数为温度300~510℃、压力32~108 MPa、平均盐度7.64%、平均密度0.69g/cm3,白钨矿主成矿阶段(晚期矽卡岩阶段)的流体参数为温度230~300℃、压力21~64 MPa、平均盐度6.99%、平均密度0.87g/cm3,石英 硫化物 碳酸盐阶段的流体参数为温度100~230℃、压力10~62 MPa、平均盐度5.81%、平均密度0.95g/cm3。白钨矿 黑钨矿石英脉的形成温度集中于110~320℃,其上限高于矽卡岩型白钨矿的温度上限,推断石英脉型黑钨矿形成温度更高。岩前钨矿成矿流体在从高温至低温的演化过程中,盐度逐渐降低、密度逐渐增大、压力逐渐降低,整体为低盐度、低密度的流体。氢氧同位素分析表明,成矿流体来源主要为岩浆水,晚期有少量大气水的加入。岩前钨矿成矿机制主要包括流体不混溶作用、流体与围岩相互反应、流体自然冷却、流体混合和压力下降,其中以CO2逸失为特征的流体不混溶作用为重要的成矿机制。岩相学观察、显微测温、激光拉曼光谱分析证实了矽卡岩型矿体及白钨矿 黑钨矿石英脉中石英的包裹体中都含有CO2。I型包裹体与Ⅳ型包裹体共存、高盐度包裹体与低盐度包裹体共存及部分I型包裹体中含子晶证明岩前钨矿成矿过程中存在流体不混溶作用。成矿过程为：成矿初期,岩浆上侵分异出富钨岩浆热液,热液与碳酸盐质围岩发生了剧烈的接触交代作用,引起了围岩中Ca2+的释放以及pH和氧逸度的升高,同时发生了大规模隐爆作用并导致了CO2流体不混溶作用。CO2参与形成了可作为W运移载体的碱金属水溶液,另外其逸失导致pH升高和氧逸度降低。成矿初期的含矿热液为高温、高压、高盐度、富钨、富钙、富挥发份、pH相对较高、偏还原之后偏氧化的流体,在温压下降及氧逸度降低的条件下白钨矿大量沉淀。白钨矿 黑钨矿石英脉由于靠近矽卡岩,所以热液中含Ca2+,但Ca2+的含量还不足以形成单一的白钨矿,所以出现了白钨矿和黑钨矿共存。对岩前钨矿成矿流体的研究进一步厘定了该区矽卡岩型钨矿的成因机制,同时有益于拓展南岭东段钨矿的找矿方向。 相似文献
11.
S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
12.
奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
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E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
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Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
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Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km2 and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world. 相似文献
19.
岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
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《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population). 相似文献