磷矿石中磷、钙、镁、锶、氟测定方法评述   总被引：2，自引：0，他引：2  

孙琳 《贵州地质》2007,24(4):322-324

本文系统分析了磷矿石高含量磷、钙、镁、锶、氟诸元素存在时对其测定的相互影响及其测定中存在的问题,比较全面地总结了国内分析工作者针对该问题,对诸难测元素在常规分析方法方面的工作进展。  相似文献   

Oscillatory zoning in garnet from the Willsboro Wollastonite Skarn, Adirondack Mts, New York: a record of shallow hydrothermal processes preserved in a granulite facies terrane     

C. C. Clechenko  J. W. Valley 《Journal of Metamorphic Geology》2003,21(8):771-784

Oscillatory zoning in low δ¹⁸O skarn garnet from the Willsboro wollastonite deposit, NE Adirondack Mts, NY, USA, preserves a record of the temporal evolution of mixing hydrothermal fluids from different sources. Garnet with oscillatory zoning are large (1–3 cm diameter) euhedral crystals that grew in formerly fluid filled cavities. They contain millimetre‐scale oscillatory zoning of varying grossular–andradite composition (X_Adr = 0.13–0.36). The δ¹⁸O values of the garnet zones vary from 0.80 to 6.26‰ VSMOW and correlate with X_Adr. The shape, pattern and number of garnet zones varies from crystal to crystal, as does the magnitude of the correlated chemistry changes, suggesting fluid system variability, temporal and/or spatial, over the time of garnet growth. The zones of correlated Fe content and δ¹⁸O indicate that a high Fe³⁺/Al, high δ¹⁸O fluid mixed with a lower Fe³⁺/Al and δ¹⁸O fluid. The high δ¹⁸O, Fe enriched fluids were likely magmatic fluids expelled from crystallizing anorthosite. The low δ¹⁸O fluids were meteoric in origin. These are the first skarn garnet with oscillatory zoning reported from granulite facies rocks. Geochronologic, stable isotope, petrologic and field evidence indicates that the Adirondacks are a polymetamorphic terrane, where localized contact metamorphism around shallowly intruded anorthosite was followed by a regional granulite facies overprint. The growth of these garnet in equilibrium with meteoric and magmatic fluids indicates an origin in the shallow contact aureole of the anorthosite prior to regional metamorphism. The zoning was preserved due to the slow diffusion of oxygen and cations in the large garnet and protection from deformation and recrystallization in zones of low strain in thick, rigid, garnetite layers. The garnet provide new information about the hydrothermal system adjacent to the shallowly intruded massif anorthosite that predates regional metamorphism in this geologically complex, polymetamorphic terrane.  相似文献   

Geology and Genesis of the Ta'ergou Skarn - Quartz Vein Tungsten Deposit in the North Qilian Caledonian Orogenic Belt, Northwest China     

Zuoheng Zhang    Jingwen Mao    Jianmin Yang    Zhiliang Wang  Zhaochong Zhang 《Resource Geology》2003,53(2):101-114

Abstract. The Ta'ergou tungsten deposit in Gansu province, northwestern China, is located in the western part of the North Qilian Caledonian orogen, and consists of scheelite skarn bodies and wolframite quartz veins. The tungsten‐bearing skarn developed by the replacement of carbonate layers intercalated in the Precambrian schist and amphibolite whereas wolframite‐quartz ore veins developed along a group of fractures that cut through horizontal skarns. The Ta'ergou tungsten deposit is genetically related to the Caledonian Yeniutan granodiorite intrusion and occurs ca. 500 m wide in the exo‐contact zone 300 ～ 500 m apart from the intrusion. The granodiorite displays a lower grade of differentiation, low content of SiO₂ and high contents of mafic components. There are three types of fluid inclusions in the wolframite‐quartz vein systems, i. e. aqueous, CO₂‐H₂O and CO₂‐rich. The homogenization temperature of aqueous inclusion ranges from 140 to 380d?C and their salinities from 6.4 to 17.4 equivalent wt% NaCl. Laser Raman spectroscopy shows that the inclusions contain a relatively high content of CO₂. The δ³⁴S values of skarn type sulfides range from +8.1 to +12.7 per mil and those of quartz vein sulfides from +9.3 to +14.9 per mil, similar to sulfides of the granodiorite with from +6.0 to +11.7 per mil. The δ¹⁸O values of quartz are between +10.5 and +13.3 per mil and those of wolframite between +3.4 and +5.1 per mil. The δ¹⁸O water values of ore forming fluids range from +0.6 to +6.4 per mil and suggest the mixture of magmatic fluids with meteoric water formed the ore‐forming fluids. It has been proved that Precambrian strata in the west sector of North Qilian region are enriched in tungsten. We propose the strata were remelted to be tungsten‐granitoid during subduction. The polymetallic tungsten was gradually accumulated into the roof pendants of the granite intrusion by fractional crystallization and then was deposited by hydrothermal fluids during metasomatism and infilling along fractures. On the other hand, the granite intrusion also acted as “heating machine” to make hydrothermal fluids leach out the metals from Precambrian strata and these metals joined the ore‐forming hydrothermal system.  相似文献   

河北寿王坟铜矿碳-氧同位素地球化学特征及其意义   总被引：3，自引：0，他引：3  

张瑞斌  刘建明  叶杰  李永兵 《矿产与地质》2003,17(2):122-126

系统研究寿王坟矿区矽卡岩型矿石和斑岩型矿石中热液成因碳酸盐矿物的碳免同位素组成，结合矿区蚀变白云质围岩地层碳免同位素组成特征，提出：1)尽管矽卡岩矿床产在碳酸盐地层与中酸性侵入体的接触带上，是碳酸盐地层受热液交代作用的产物，但矽卡岩矿石中热液碳酸盐矿物的碳同位素组成却主要反映了深部岩浆(甚或地馒)来源碳的特征，基本可以排除沉积碳酸盐的碳大规模加入的可能性。2)寿王坟矿田对应着一个与高侵位岩浆岩有关的热液成矿系列，其浅部的下渗大气降水加热环流体系和深部上升的岩浆热液体系，均能在不同部位通过系统的碳免同位素地球化学研究加以揭示。作为矿山开采主体的矽卡岩型矿体和部分斑岩型矿体都是上升岩浆热液(甚或更深的馒源流体)的产物。  相似文献   

层控夕卡岩型矿床成矿系统的元素活动性及质量迁移--以铜陵冬瓜山铜矿床为例   总被引：7，自引：0，他引：7  

凌其聪  刘丛强 《矿物学报》2003,23(1):37-44

应用改善了的质量平衡方程研究冬瓜山层控夕卡岩型铜矿床成矿系统的元素活动性及质量迁移，结果表明：系统中Zr,Hf,Y和Nb为不活动元素，其余均为活动元素。主量元素中仅CaO为迁出组分，其质量迁移量为84％，其余均为带入组分，带入量最大的SiO2的质量迁移量高达2384％；稀土元素均为带入组分，其中，中稀土较轻稀土和重稀土的活动性更强；其它微量元素中，带入序列由强到弱为：Cr→Ta→Sn→Th，迁出序列由强至弱依次为：U→Sb→Ni—Sr→Ba→Bb→Co→W；成矿元素Cu和Ag为带入组分，其中Cu的带入量最大，质量迁移量高达1200％。本文还得出两点具普适性认识：①稀土元素较其它微量元素对体系条件的变化更为敏感，且往往表现出明显的规律性变化，能更好地示踪地质地球化学过程。②不同元素在不同体系中的行为特征差异极大，仅凭经验判定某一元素为不活动元素往往不可靠。因此，在开展质量平衡研究时，首先采用适当方法确认体系的不活动元素是一项不可或缺的前提工作。  相似文献   

Rb2Ca[B4O5(OH)4]2·8H2O溶解及相转化过程的研究   总被引：2，自引：0，他引：2       下载免费PDF全文

王奖  朱黎霞  李淑妮  王波  夏树屏 《盐湖研究》2005,13(1):25-30

利用IR光谱和Raman光谱等实验手段,对25℃时Rb2Ca[B4O5(OH)4]2·8H2O的溶解及相转化过程进行了初步探索,结果表明,Rb2Ca[B4O5(OH)4]2·8H2O溶于水后,硼在溶液中主要以B(OH)3和[B(OH)4]-的形式存在,残留固相由开始的无定形水合三硼酸钙,最终部分转变为Ca2[B3O3(OH)5]2·8H2O晶体。  相似文献   

新疆尼勒克县哈勒尕提铜铁矿地质特征及找矿前景   总被引：1，自引：0，他引：1  

曹景良 《地质找矿论丛》2005,20(Z1):120-124

文章介绍了新疆尼勒克县哈勒尕提铜铁矿成矿地质背景和矿区地质特征、矿体特征、矿物成分、微量元素分布特征等,指出该矿具备大型矿床的成矿条件,有较大的找矿前景.  相似文献   

广东省藤铁铁矿成矿地质特征     

武金阳 《地质找矿论丛》2005,20(Z1):131-133

藤铁铁矿位于鱼鹿岩枝东接触带中段,该矿体为铁、铜、锡共(伴)生矿床.受断裂带、岩体侵入接触带、夕卡岩带和鱼鹿岩枝控制.据此总结出该区"三带一体"的成矿特征.  相似文献   

A Reflection on Mg, Cd, Ca, Li and Si Isotopic Measurements and Related Reference Materials   总被引：6，自引：1，他引：6  

Jean Carignan  Damien Cardinal  Anton Eisenhauer  Albert Galy  Mark Rehkamper  Frank Wombacher  Nathalie Vigier 《Geostandards and Geoanalytical Research》2004,28(1):139-148

This contribution aims to report the reflections we had with the scientific community during two international workshops on reference materials for stable isotopes in Davos (2002) and Nice (2003). After evaluating the isotopic homogeneity of some existing reference materials, based on either certificates, literature data or specific inter-laboratory rounds, we confirm these as primary reference materials or propose new ones relative to which stable isotope compositions should be reported. We propose DSM-3 for Mg, NIST SRM 915a for Ca, L-SVEC for Li and NBS28 for Si. Cadmium does not yet have a well identified delta zero material, although three commercial mono-elemental Cd solutions have yielded the same isotopic composition relative to one another. In order to scale the linearity of any mass spectrometer, some secondary reference materials are also proposed: Cambridge-1 solution for Mg, the "Münster-Cd" and JEPPIM Cd solutions for Cd and the "Big Batch" silicate for Si. The team from Nancy propose to prepare a mixed spike solution for Li isotopes. Well-characterised natural samples such as ocean or continental waters, diatoms, sponges, rocks and minerals are needed to validate the entire analytical procedure, particularly to take into account the effect of sample mineralisation and of chemical manipulations for elemental separation prior to analysis.  相似文献   

从赋矿岩系岩石类型的多样性论羊拉铜矿的成因   总被引：17，自引：0，他引：17  

曲晓明  杨岳清  李佑国 《矿床地质》2004,23(4):431-442

通过野外调查和室内工作，将羊拉铜矿床按矿石的矿物成分和组构分出9种类型，包括矽卡岩型、大理岩型、砂板岩型、角岩型、凝灰质流纹岩型、玄武岩-辉绿岩型、花岗质碎裂岩-花岗斑岩型、安山岩型和绢英岩型。矽卡岩型矿石是构成矿体的最主要矿石类型，但在不同矿段可由碳酸盐岩(里农)和凝灰质火山岩(贝吾)两种原岩形成。矿体在赋矿岩系中有3种产出形态：顺层呈层状．似层状；沿花岗岩与沉积岩接触面呈透镜状；贯穿岩体和沉积岩呈大脉状。它们均与后期构造密切相关，矿体无确定的顶、底板岩石，围岩蚀变以矿体为中心呈环带状分布。研究表明，矿床相对赋矿岩系显示出明显的后成性，属于印支期花岗岩-花岗斑岩与古生代混杂岩通过强烈的接触交代作用形成的矽卡岩型铜矿床。  相似文献