scholarly journals Chemical Evolution of Nb-Ta Oxides and Cassiterite in Phosphorus-Rich Albite-Spodumene Pegmatites in the Kangxiwa–Dahongliutan Pegmatite Field, Western Kunlun Orogen, China

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 166 ◽  
Author(s):  
Yonggang Feng ◽  
Ting Liang ◽  
Xiuqing Yang ◽  
Ze Zhang ◽  
Yiqian Wang
Keyword(s):  
Trace Element ◽  
Optical Microscopy ◽  
Chemical Evolution ◽  
Major Element ◽  
Sector Zoning ◽  
Icp Ms ◽  
Western Kunlun ◽  
Compositional Variations ◽  
Mineral Scale ◽  
Western Kunlun Orogen

The Kangxiwa–Dahongliutan pegmatite field in the Western Kunlun Orogen, China contains numerous granitic pegmatites around a large granitic pluton (the Dahongliutan Granite with an age of ca. 220 to 217 Ma), mainly including barren garnet-, tourmaline-bearing pegmatites, Be-rich beryl-muscovite pegmatites, and Li-, P-rich albite-spodumene pegmatites. The textures, major element contents, and trace element concentrations of columbite-group minerals (CGM) and cassiterite from three albite-spodumene pegmatites in the region were investigated using a combination of optical microscopy, SEM, EPMA and LA-ICP-MS. The CGM can be broadly classified into four types: (1) inclusions in cassiterite; (2) euhedral to subhedral crystals (commonly exhibiting oscillatory and/or sector zoning and coexisting with magmatic cassiterite); (3) anhedral aggregates; (4) tantalite-(Fe)-ferrowodginite (FeSnTa2O8) intergrowths. The compositional variations of CGM and cassiterite are investigated on the mineral scale, in individual pegmatites and within the pegmatite group. The evolution of the pegmatites is also discussed. The variation of Nb/Ta and Zr/Hf ratios of the cassiterite mimics the Nb-Ta and Zr-Hf fractionation trends in many LCT pegmatites, indicating that these two ratios of cassiterite may bear meanings regarding the pegmatite evolution.

Combined Major and Trace Element LA-ICP-MS Analysis of Compositional Variations in Simple Solid Solutions through Cross Correlation with an EPMA-Characterized Working Standard

2012 ◽  
Vol 18 (4) ◽  
pp. 852-859 ◽  
Author(s):  
Georg F. Zellmer ◽  
Peter Dulski ◽  
Yoshiyuki Iizuka
Keyword(s):  
Trace Element ◽  
Solid Solutions ◽  
Inductively Coupled Plasma ◽  
Cross Correlation ◽  
Beam Diameter ◽  
Relative Uncertainty ◽  
Working Standard ◽  
Epma Data ◽  
Icp Ms ◽  
Compositional Variations

AbstractDetermining correlated major and trace element zoning profiles is an important goal in modern microanalysis and is critical to some geospeedometric applications. We show that a precise determination of relative variations in major element compositions of simple solid solutions is possible by LA-ICPMS, and that low accuracy (analytical bias) can be corrected for through cross correlation with electron problem microanalyzer (EPMA)-characterized working standards. Further, the relative uncertainties on binary or quasibinary solid solution endmember proportions are always lower than the relative uncertainties on the ratio of the principle substituting elements by at least a factor of 2. In calcic plagioclase, for example, the relative uncertainty on XAn is a factor of (1 − XAn) smaller than the relative uncertainty on Ca/Na. Using a well-characterized, concentrically zoned bytownite crystal as an example, we compare reproducibilities of FE-EPMA and W-EPMA analyses with 2 μm beam diameter and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with 16 μm beam diameter. While the accuracy of LA-ICP-MS analyses is low (analytical bias), the precision of LA-ICP-MS analyses is slightly higher than that of FE-EPMA data and comparable to that of the W-EPMA data. EPMA-corrected LA-ICP-MS data can thus be used to characterize major oxide compositional variations and potential covariations with trace elements within individual crystals.

TRACE ELEMENT ANALYSIS OF PYRITES IN GAS SHALES BY LASER ABLATION ICP-MS: IMPLICATIONS FOR MOBILITY

2017 ◽  
Author(s):  
Amy K. Plechacek ◽  
◽  
Madeline E. Schreiber ◽  
John A. Chermak ◽  
Tracy L. Bank
Keyword(s):  
Laser Ablation ◽  
Trace Element ◽  
Trace Element Analysis ◽  
Element Analysis ◽  
Icp Ms ◽  
Gas Shales

LA-ICP-MS U Pb columbite ages and trace-element signature from rare-element granitic pegmatites of the Pampean Pegmatite Province, Argentina

Lithos ◽  
2021 ◽  
Vol 386-387 ◽  
pp. 106001
Author(s):  
Miguel Ángel Galliski ◽  
Albrecht von Quadt ◽  
María Florencia Márquez-Zavalía
Keyword(s):  
Trace Element ◽  
Rare Element ◽  
Granitic Pegmatites ◽  
Icp Ms ◽  
Trace Element Signature

scholarly journals Accumulation of Elements in Biodeposits on the Stone Surface in Urban Environment. Case Studies from Saint Petersburg, Russia

2020 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Katerina V. Sazanova (nee Barinova) ◽  
Marina S. Zelenskaya ◽  
Vera V. Manurtdinova ◽  
Alina R. Izatulina ◽  
Aleksei V. Rusakov ◽  
...  
Keyword(s):  
Microbial Community ◽  
Optical Microscopy ◽  
Elemental Composition ◽  
Urban Environment ◽  
Microbial Metabolites ◽  
Stone Surface ◽  
Saint Petersburg ◽  
Icp Ms ◽  
Living Organisms ◽  
Selective Accumulation

The pattern of elements accumulation in biodeposits formed by living organisms and extracellular products of their metabolism (biofouling, primary soils) on different bedrocks (of the monuments of Historical necropoleis in Saint Petersburg) were studied by a complex of biological and mineralogical methods (optical microscopy, SEM, EDX, XRD, ICP MS, XRFS). The content of 46 elements in biodeposits with various communities of microorganisms is determined. The model recreating the picture of the input and selective accumulation of elements in biodeposits on the stone surface in outdoor conditions is assumed. It is shown that the main contribution to the elemental composition of biodeposits is made by the environment and the composition of the microbial community. The contribution of leaching under the action of microbial metabolites of mineral grains, entering biodeposits from the environment, is significantly greater than that of the underlying rock.

scholarly journals Geochemical signatures of mineralizing events in the Juomasuo Au–Co deposit, Kuusamo belt, northeastern Finland

2021 ◽  
Author(s):  
Mikael Vasilopoulos ◽  
Ferenc Molnár ◽  
Hugh O’Brien ◽  
Yann Lahaye ◽  
Marie Lefèbvre ◽  
...  
Keyword(s):  
Trace Element ◽  
Sulfur Isotope ◽  
Mineral Chemistry ◽  
Chemical Compositions ◽  
Metasedimentary Rocks ◽  
Metavolcanic Rocks ◽  
Icp Ms ◽  
Stage 1 ◽  
Host Rocks ◽  
Relationship Of

AbstractThe Juomasuo Au–Co deposit, currently classified as an orogenic gold deposit with atypical metal association, is located in the Paleoproterozoic Kuusamo belt in northeastern Finland. The volcano-sedimentary sequence that hosts the deposit was intensely altered, deformed, and metamorphosed to greenschist facies during the 1.93–1.76 Ga Svecofennian orogeny. In this study, we investigate the temporal relationship between Co and Au deposition and the relationship of metal enrichment with protolith composition and alteration mineralogy by utilizing lithogeochemical data and petrographic observations. We also investigate the nature of fluids involved in deposit formation based on sulfide trace element and sulfur isotope LA-ICP-MS data together with tourmaline mineral chemistry and boron isotopes. Classification of original protoliths was made on the basis of geochemically immobile elements; recognized lithologies are metasedimentary rocks, mafic, intermediate-composition, and felsic metavolcanic rocks, and an ultramafic sill. The composition of the host rocks does not control the type or intensity of mineralization. Sulfur isotope values (δ34S − 2.6 to + 7.1‰) and trace element data obtained for pyrite, chalcopyrite, and pyrrhotite indicate that the two geochemically distinct Au–Co and Co ore types formed from fluids of different compositions and origins. A reduced, metamorphic fluid was responsible for deposition of the pyrrhotite-dominant, Co-rich ore, whereas a relatively oxidized fluid deposited the pyrite-dominant Au–Co ore. The main alteration and mineralization stages at Juomasuo are as follows: (1) widespread albitization that predates both types of mineralization; (2) stage 1, Co-rich mineralization associated with chlorite (± biotite ± amphibole) alteration; (3) stage 2, Au–Co mineralization related to sericitization. Crystal-chemical compositions for tourmaline suggest the involvement of evaporite-related fluids in formation of the deposit; boron isotope data also allow for this conclusion. Results of our research indicate that the metal association in the Juomasuo Au–Co deposit was formed by spatially coincident and multiple hydrothermal processes.

Sign in / Sign up

Export Citation Format

Share Document