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1.
The Huangsha Ag-rich tungsten deposit is genetically related to a buried granite which shows apparent vertical zoning in alteration.Greisen-type W(Mo) ores coccur at the top or the intrusive and sulfide-wolframite-quartz veins developed at the major stage of mineralization are present in low-grade metamorphic rocks in the outer-contacts.The veins exhibit a reversed zonation in the vertical section with silver concentrated in the lower part in association with sulfides.Micas,characterized by high Si and low Al.are extensively developed both in the granite and in the veins.They have similar cell parameters.belonging to 2M1 type,but those in the veins are understanding of the petrogenesis, evolution and mineralization of the granite. 相似文献
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The total rare-earth element values(ΣREE)of loess in the Xinjiang region vary over a range of 128-200 ppm ,with an average of 153ppm .The average REE content of loess lies between the earth‘s crust (155ppm) and sedimentary rocks(151ppm).The Xinjiang loess,with the REE distribu-tion patterns characterized by negative slopes ,is rich in the Ce-family elements, and has a distribu-tion pattern characteristic of sedimentary rocks.The North Xinjiang loess is relatively depleted in Tb,but rich in Yb and Lu.The South Xinjiang loess is relatively rich in light rare-earth elements.This is full proof that the Xinjiang loess comes partly from weathered materials(clay rock,sandstone)in the region studied.The REE distribution patterns in the Xinjiang loess are similar to those in the precipitated dust and Aeolian sand,indicating the same material source.The REE distribution pat-terns in the Xinjiang loess are also similar to those in loess from the middle Yellow River Valley,China and Taskent,the former USSR.This implies that loesses of the three locations(Xinjiang,the mid-dle Yellow River Valley and Taskent) come from a common material source.But the REE patterns in the Xinjiang loess are different from those in wall rocks (volcanic rock,K-bearing volcanic rock).Generally ,LREE/HREE,Eu/Eu* and Ce/Ce* ratios reflect the features of parent materials of loess,indicating that the parent rocks were probably in the early stage of alkaline weathering and the weathered materials existed in an oxidation environment with basic mediums under arid-climatic conditions before transport.As a result,the migration ability of the REE is weak. 相似文献
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Please?refer?to?the?attachment(s)?for?more?details. 相似文献
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Henrik Friis Adrian A. Finch C. Terry Williams John M. Hanchar 《Physics and Chemistry of Minerals》2010,37(6):333-342
The photoluminescence properties of synthetic zircon, ZrSiO4, doped with REE3+ (REE = Pr, Sm, Eu, Gd, Dy, Ho, Er) were investigated using combined excitation and emission spectroscopy. All samples showed
luminescence characteristics of intra-ion energy transitions, similar to other lanthanide-doped materials. However, the relative
intensities were dependent on the energy of excitation and the presence of charge-transfer bands were inferred from excitation
spectra. From the data, we conclude that the lanthanides in zircon occur in more than one type of coordination. Energy transfer
between different lanthanides was observed in some co-doped samples and emissions that were unassigned in previous studies
have been assigned to specific lanthanides based on excitation spectroscopy. 相似文献
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REE Geochemistry of Fluorite from the Maoniuping REE Deposit, Sichuan Province, China: Implications for the Source of Ore-forming Fluids 下载免费PDF全文
HUANG Zhilong XU Cheng Andrew McCAIG LIU Congqiang WU Jing XU Deru LI Wenbo GUAN Tao XIAO Huayun 《《地质学报》英文版》2007,81(4):622-636
Fluorite is one of the main gangue minerals in the Maoniuping REE deposit,Sichuan Province,China.Fluorite with different colors occurs not only within various orebodies,but also in wallrocks of the orefield.Based on REE geochemistry,fluorite in the orefield can be classified as the LREE-rich,LREE-flat and LREE-depleted types.The three types of fluorite formed at different stages from the same hydrothermal fluid source,with the LREE-rich fluorite forming at the relatively early stage,the LREE-flat fluorite in the middle,and the LREE-depleted fluorite at the latest stage.Various lines of evidence demonstrate that the variation of the REE contents of fluorite shows no relation to the color.The mineralization of the Maoniuping REE deposit is associated spatially and temporally with carbonatite-syenite magmatism and the ore-forming fluids are mainly derived from carbonatite and syenite melts. 相似文献
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Zhaozhou ZHU Congqiang LIU Zhongliang WANG Bo GAO Zhihua ZHOU Jun LI 《中国地球化学学报》2006,25(B08):150-150
The rare-earth elements (REEs) are a series of elements including lanthanides with atomic numbers from 57 to 71, as well as Y with an atomic number of 39. The REEs are commonly used as geochemical tracers in the study of many geologic processes because of their unique and chemically coherent behavior. The main purpose of this research is to understand the effect of water-particle interaction on trace metal transport, the distribution and chemical species of the REEs in water through case studies on geochemical behavior of the REEs in the Chaohu and Longgan lakes, eastern China. Concentrations of the dissolved REEs were detected by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry). Before ICP-MS measurement, REEs were concentrated from water samples by using solvent extraction and back extraction with a mixture 65% HDEHP (2-etheylhexyl hydrogen phosphate) and 35% H2MEHP (2-ehtylhexyl dihydrogen phosphate). The results showed that the average concentrations of dissolved REEs in summer are higher than in winter for Chaohu Lake: they were 162.6 ng/kg and 86.5 ng/kg, respectively. On the country, the REE contents of winter samples were higher than those of summer water samples for Longganhu Lake: they were 111.1 ng/kg and 44.0 ng/kg, respectively. The contents of suspended particulate matter and pH are the two important factors controlling the concentrations of dissolved REE in the lakes. The contents of the REEs decrease with increasing pH in the Longgan and Chaohu lakes. The suspended particulate matter shows different sorption/desorption toward the dissolved REEs in the two water bodies. Most lake water samples have a fiat NASC-normalized REE pattern, and the others have heavy REE-enrichment patterns relative to NASC, which may imply that the dissolved REEs were mainly present in the form of fine colloids in the Chaohu and Longgan lakes. 相似文献
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Please refer to the attachment(s) for more details. 相似文献
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Warm and humid climate and gentle hilly topography have provided favourable conditions for the devel-opment of the weathering crust of the granite intrusions in the Longnan area, Jiangxi Province. REE is mostlyconcentrated in an adsorption state in clay in the wholly weathered zone. The rare-earth minerals enriched inthe parent rocks provided the source material for the REE enrichment. Exchangeable REE accounts for48-86%. Extraction experiments and stable isotopic study of clay minerals suggest that the downward infiltra-tion of meteoric water and increasing gradient of pH values have played an important role in the enrichment ofREE during the progressive weathering. Slight fractionation of individual REE can not change their distribu-tion patterns in the profiles. which are inherited from the parent rocks. 相似文献
10.
REE Geochemical Characteristics of Two Granite-Derived Weathering Profiles, Guangxi, South China: Implications for the Formation of the Ion Adsorption Type REE Deposit 下载免费PDF全文
Please refer to the attachment(s) for more details. 相似文献
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REE and Trace Element Geochemistry of Yinachang Fe-Cu-REE Deposit, Yunnan Province, China 总被引:3,自引:0,他引:3
1IntroductionThebehaviorsoftherare earthelements (REE)duringmagmatism ,metamorphismandmeta somationareofgreatgeologicalinterestbecauseoftheirapplicationsingeochronologyandgeochemi caltracing (e .g .reviewsbyFaure ,1 986;LipinandMckay ,1 989) .Becauseoftheirsimilargeo chemicalbehaviorsandlowsolubilitiesinwater,theREEshaveprovedthemselvestobeapowerfultoolforthecharacterizationofprovenanceswhenappliedtosedimentaryrocks (McDanieletal.,1 994) .Althoughtheirbehaviorsunderhydrothermalconditionsar… 相似文献
13.
Qiu Ruilong 《《地质学报》英文版》1987,61(1):105-115
This paper presents REE abundance pattern and REE geochemistry of granodiorite porphyry, skarns, as well as late hydrothermal alterations in the Tongshan copper deposit, Guichi County and, in the light of their similarities and variations, deals with the genesis of the skarns and the transformation process of the post-skarn hydrothermal alterations. On such a basis, the inference is drawn that the skarn-forming solution was produced by further fractionation of residual magma, thus belonging to a transitional fluid between residual magma and hydrothermal solution which, with the continuous variation of its components during the metasomatism, tended to become a hydrothermal solution. 相似文献
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1 Introduction Alunite [KAl3(SO4)2(OH)6] is a very important non-ferrous metal resource, so many countries throughout the world have made great investments in research on the mechanism of its formation, its geological characteristics and applications. O… 相似文献
16.
REE Geochemical Evolution and Its Significance of Early Precambrian Metamorphic Terrain,Wuyang,Henan
The supracrustal rocks of the Wuyang metamorphic terrain are divided into the Zhao anzhuang,Tieshanmiao and Yangshuwan Formations.These three Formations were dated at 3000-2550Ma,2550-2300Ma and 2300-2200Ma,respectively.∑REE and La/Yb)n of the Zhao anzhuang Formation volcanic rocks are obviously higher than those of the Tiesanmiao Formation equivalents,suggesting a sedimentary gap(2550 Ma boundary)between these two formations,The Zhao‘anzhuang Formation is older than the Tieshanmiao Formation.The sediments of these two Formations show no obvious differences in REE and are generally characterized by low ∑REE and positive Eu anomalies.On the contrary,the sediments of the Yangshuwan Formation are characterized by high ∑REE and negative Eu anomalies.Detailed discussions demonstrate that the Yangshuwan Formation was deposited in an oxidizing environment whereas the other two formations were formed in a reducing environment.At the end of the evolution of the Tieshanmiao Formation about 2300 Ma ago,the sedimentary environment was transformed from reducing to oxidizing .On the basis of the SHAB (soft/hard acid and base)theory,an oxidation-reduction model for sedimentary REE evolution has been established .It is proposed that the mantle tends to become gradually depleted in REE.especially in LREE,and the indices ∑REE and La/Yb) n of mantle-dervived volcanic rocks also tend to become lower and lower. 相似文献
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The accessory minerals apatite and sphene are the main carriers of REE in alkaline rocks.Their chondrite-normalized REE patterns decline sharply to the right as those of the host rocks,In the patterns an obvious negative Eu anomaly and a positive Ce anomaly can be seen in apatite and sphene,respectively.Zircon from alkaline rocks is different in REE pattern,I,e,. a nearly symmetric“V“-shaped pattern with a maximum negative Eu anomaly.Compared with the equivalents from granites,apatite,sphene and zircon from alkaline rocks are all characterized by higher (La/Yb)N ratio and less Eu depletion,As to the relative contents of REE in minerals,apatite,sphene and zircon are enriched in LREE,MREE and HREE respectively,depending on their crystallochemical properties. 相似文献
18.
REE Compositions of Lower Ordovician Dolomites in Central and North Tarim Basin, NW China: A Potential REE Proxy for Ancient Seawater 总被引:2,自引:1,他引:1
ZHANG Xuefeng HU Wenxuan JIN Zhijun ZHANG Juntao QIAN Yixiong ZHU Jingquan ZHU Dongya WANG Xiaolin XIE Xiaomin 《《地质学报》英文版》2008,82(3):610-621
Rare earth element compositions of Lower Ordovician dolomites in the Central and Northern Tarim Basin are studied. Most dolomite samples are more or less contaminated by clay minerals. Their rare earth element compositions have been consequently changed, showing both seawater-like and non-seawater-like features. The clay contamination should be disposed before the REE data are used. Through ICP-MS and ICP-AES analyses, the REE features are well documented. The clay contamination is quantitatively determined by microscopic investigation, trace elements and REE contents. The dolomites, at least in the Tarim Basin, are thought to be pure when their total LREE contents are less than 3×10^-6. Through comparison, the pure dolomites show similarities in REE patterns but differences in REE contents with co-existing pure limestone, which indicates that dolomitization may slightly change the REE compositions. Nevertheless, whatever the change is, the pure dolomites may act as a potential REE proxy for Ordovician seawater, which would be significant for ancient massive dolomite strata that lack limestone. 相似文献
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黔西北地区的织金、威宁、毕节、大方、纳雍、赫章等县均出现REE矿床或矿化,可分为2类:一类是寒武系底部的海相沉积磷块岩磷-REE矿床,如织金新华;另一类是与峨眉山玄武岩有关的古风化壳粘土岩REE矿化。本文主要介绍后一类。黔西北地区在大地构造上位于扬子准地台黔北台隆。区内峨眉山玄武岩广泛分布,主要为大陆溢流玄武岩,呈岩被产出,假整合于上二叠统茅口组灰岩之上,其上覆地层主要为上二叠统宣威组含煤岩系。玄武岩最厚处在西部威宁附近,厚达1249m。区内,在宣威组与玄武岩之间及玄武岩内部,产有多层呈似层状、透镜状的粘土岩,以高岭石… 相似文献
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REE示踪沉积物物源研究进展 总被引:101,自引:0,他引:101
REE作为一种重要的沉积物物源示踪剂运用很广。在介绍了REE性质的基础上,对海水、河水、沉积岩、河流及边缘海沉积物中的REE元素丰度与配分模式特征进行了深入综述,概述了影响和控制REE丰度、模式及分馏特征的主要因素;论述了REE的物泊示踪意义以及在国内外应用情况与存在问题:源岩风化对REE分馏的影响;颗粒运及沉积时水动力分选对REE分馏可能造成的影响,即不同粒级中的REE不同的丰度与配分模式和碎屑 相似文献