电感耦合等离子体发射光谱法测定富镁铁橄榄岩类矿石中铜镍铁和氧化镁   总被引：2，自引：2，他引：0  

张旺强  王春妍  李瑞仙  巨力佩  陈月源  余志峰  毛振才 《岩矿测试》2011,30(2):195-199

样品经氢氟酸-盐酸-硝酸-高氯酸混合酸一次加入冷浸直接溶解,在5%(体积分数)的盐酸介质中,用电感耦合等离子体发射光谱法测定富镁铁橄榄岩类矿石中的铜、镍、铁、氧化镁,克服了传统分析方法操作繁琐、周期长、成本高,而过程难以控制等缺点。方法检出限为铜2.0μg/g,镍3.0μg/g,铁10μg/g,氧化镁20μg/g;精密度(RSD,n=12)为0.8%～4.1%。经国家一级标准物质分析验证,测定值与标准值吻合,结果准确可靠。对于富镁铁岩类矿石中含量较高的硫化物的测定,采用一次加混合酸冷浸除硫后,再加热分解样品,结果令人满意;其中含量较高的铁和氧化镁,采用分取稀释测定,减小基体干扰。建立的方法样品处理程序简单快速,线性范围宽,分析重现性好,适用于地质部门批量样品的分析。  相似文献   

金平阿德博铜镍矿区王家寨矿段矿床成因探讨     

韦文彪  肖元元  沈良 《云南地质》2011,30(3):285-288

矿床与华力西期超基性一基性一中性岩浆杂岩关系密切,成矿专属性明显。先期矿浆在杂岩体中初步熔离富集,后期矿浆在压力作用下沿断裂贯入,经期后热液改造再富集成矿。  相似文献   

云南金平亚拉寨镍矿矿石组份及其综合利用     

朱启金 《云南地质》2011,30(3):289-293

亚拉寨镍矿属岩浆熔离型与晚期岩浆结晶分异型复合的硫化物矿床。矿体赋存于基性～超基性杂岩体底部,有用元素镍平均0.44ω%,伴生铜、钴等。对矿石组份及其赋存状态研究后,提出综合利用建议。  相似文献   

The Catalão I niobium deposit, central Brazil: Resources, geology and pyrochlore chemistry     

Pedro Filipe de Oliveira Cordeiro  José Affonso Brod  Matheus Palmieri  Claudinei Gouveia de Oliveira  Elisa Soares Rocha Barbosa  Roberto Ventura Santos  José Carlos Gaspar  Luis Carlos Assis 《Ore Geology Reviews》2011,41(1):112-121

The Catalão I alkaline–carbonatite–phoscorite complex contains both fresh rock and residual (weathering-related) niobium mineralization. The fresh rock niobium deposit consists of two plug-shaped orebodies named Mine II and East Area, respectively emplaced in carbonatite and phlogopitite. Together, these orebodies contain 29 Mt at 1.22 wt.% Nb₂O₅ (measured and indicated). In closer detail, the orebodies consist of dike swarms of pyrochlore-bearing, olivine-free phoscorite-series rocks (nelsonite) that can be either apatite-rich (P2 unit) or magnetite-rich (P3 unit). Dolomite carbonatite (DC) is intimately related with nelsonite. Natropyrochlore and calciopyrochlore are the most abundant niobium phases in the fresh rock deposit. Pyrochlore supergroup chemistry shows a compositional trend from Ca–Na dominant pyrochlores toward Ba-enriched kenopyrochlore in fresh rock and the dominance of Ba-rich kenopyrochlore in the residual deposit. Carbonates associated with Ba-, Sr-enriched pyrochlore show higher δ¹⁸O_SMOW than expected for carbonates crystallizing from mantle-derived magmas. We interpret both the δ¹⁸O_SMOW and pyrochlore chemistry variations from the original composition as evidence of interaction with low-temperature fluids which, albeit not responsible for the mineralization, modified its magmatic isotopic features. The origin of the Catalão I niobium deposit is related to carbonatite magmatism but the process that generated such niobium-rich rocks is still undetermined and might be related to crystal accumulation and/or emplacement of a phosphate–iron-oxide magma.  相似文献   

2009/2010年El Ni(n)o事件变化特征及其机理   总被引：3，自引：2，他引：1  

陈锦年  王宏娜  王东晓  左涛 《海洋学报》2011,33(6):29-38

应用TAO (Tropical Atmosphere Ocean project)热带太平洋实测海温和风场资料,分析研究了发生在2009/2010年的El Ni(n)o事件的变化特征,讨论了此次El Ni(n)o事件发生过程中,赤道东、西太平洋次表层异常海温的变化特征及其传播过程,特别是对赤道太平洋次表层异常海温变化的...  相似文献   

Influence of ENSO variability on sinking-particle fluxes in the northeastern equatorial Pacific     

Hyung Jeek Kim 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(8):865-874

A time-series sediment trap was operated from July 2003 to July 2008 at a station located in the 10°N thermocline ridge of the northeastern equatorial Pacific (10°30′N, 131°20′W), with the aim of understanding variations in natural background sinking-particle flux and the influence on such fluxes of ENSO (El Niño-Southern Oscillation). Each one of weak El Niño, moderate El Niño and moderate La Niña were observed during the monitoring period. During non-ENSO periods, total mass fluxes varied from 4.1 to 36.9 mg m⁻² d⁻¹, with a distinct seasonal variation, ranging from an average flux of 14.0 mg m⁻² d⁻¹ in the warm season (June-November) to 25.3 mg m⁻² d⁻¹ in the cold season (December-May). This seasonal fluctuation was characterized by a distinct difference in CaCO₃ flux between the two seasons. The enhanced particle fluxes during the cold season are attributed to the supply of nutrient-enriched subsurface water by wind-driven vertical mixing, supported by a simultaneous reduction in sea surface temperature and enhanced trade winds. The weak El Niño event occurred in the monitoring period had no recognizable effect on particle fluxes in the study area, but the moderate El Niño event was accompanied by a significant reduction in particle fluxes to 60% of the average background value in the warm season. In contrast, particle fluxes during the moderate La Niña increased to a maximum value of 129.9 mg m⁻² d⁻¹, almost three times the average background value. Organic carbon and biogenic silica fluxes were most sensitive to the El Niño and La Niña conditions. The observed variations of particle fluxes are synchronized with those of chlorophyll-a, suggesting primary productivity for the main cause of flux change. The present data indicate that marked seasonal variability in background fluxes commonly exceeds the variability associated with ENSO and post-ENSO signals, which should be taken into account when evaluating the influence of ENSO on sinking particle fluxes in the 10°N thermocline ridge area.  相似文献   

Varicolored and vesiculated tuffs from La Fossa volcano,Vulcano Island (Aeolian Archipelago,Italy): evidence of syndepositional alteration processes   总被引：1，自引：0，他引：1  

B. Capaccioni  S. Coniglio 《Bulletin of Volcanology》1995,57(1):61-70

Chemical and mineralogical data for samples collected from a surge sequence from La Fossa cone (Vulcano Island, Italy) show a wide variety of alteration states between adjoining beds, the macroscopic features of which are expressed by various degrees of reddening. The effects of the alteration processes on pyroclastic rocks are as follows: hydration and oxidation of each component of the pyroclastic rocks to varying degrees; formation of authigenic smectite; precipitation of a large variety of soluble salts; and corrosion on the surface of glass fragments (pitting). Dry surge beds, emplaced from a two-phase, dry steam + solid, suspension do not show significant alteration. By contrast, wet surge deposits, suggesting an emplacement from free water-bearing turbulent flows, show an increasing degree of alteration, passing from grey to red coloured beds. The strict relationship between the present alteration state and the depositional unit rules out any post-depositional processes. The occurrence of alteration in wet surge beds and the lack of alteration in dry beds shows that the main controlling agent was water condensed from the eruptive cloud and suggests a syn-depositional character to the alteration itself. These observed differences can be ascribed to the different chemical reactivities of the water, probably related to the amounts of acidic species carried by the eruptive cloud and/or by the efficiency of their capture during the condensation of the water vapour.  相似文献   

六棱山北麓断裂新活动特征   总被引：6，自引：1，他引：6  

段瑞涛  方仲景 《地震地质》1995,17(3):207-213

通过对六棱山北麓活动断裂的几何结构、分段活动特征及段落边界等方面的地质地貌调查与研究，认为该活动断裂可分为４段，除东段在早更新世有过活动外，其他３段均为晚更新世晚期～全新世活动段，段落长度１０～３９ｋｍ。该断裂在晚中生代表现为逆冲性质，至新生代随区域构造应力场的变化而转变为倾滑正断层。各段落上垂直位移量分布呈包络线状，而且各段平均滑动速率不同，西大东小，显示断裂新活动强度自西向东变弱  相似文献   

广宁深层次推覆构造前缘陡倾带变形构造研究   总被引：6，自引：0，他引：6  

张伯友  俞鸿年 《地震地质》1995,17(4):405-415

河台含金韧性剪切带是广宁深层次推覆构造前缘的一个陡倾带，它又是继推覆剪切之后再行右旋走滑剪切的复合带。首先解析了河台带中推覆与走滑两期构造变形的存在，并研究了带中的变形特征和运动规律及估算了几个主要糜棱岩带的水平走滑距离。通过显微镜和透射电镜，还研究了糜棱岩的显微、超显微构造，估算了变形的差异应力和应变速率  相似文献   

日食与厄尔尼诺、拉尼娜现象   总被引：2，自引：0，他引：2  

赵佩章  陈健等 《沙漠与绿洲气象(新疆气象)》2001,24(1):1-4

由资料分析出厄尔尼诺、拉尼娜现象是由日食形成的受迫振荡，以日食形成的有效位能说明日食改变大气环流，从而形成厄尔尼诺、拉尼娜的机制。  相似文献