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This annual review of secondary ion mass spectrometry (SIMS) highlights significant progress in the application of the technology for the following areas: U-Pb geochronology (notably in the fields of reference material zircons), sources of uncertainty during analysis and secondary ion yields. Major publications introduced a new zircon reference sample and dealt with an intercomparison study of a suite of established calibrators, some of which have been shown to have certain limitations. Another publication claimed that the principal uncertainty in U-Pb dating is related to variations in the Pb and U relative emission yields over a complete analytical session. 2003 saw the introduction of an automated particle identification procedure applied to the analysis of a chondritic meteorite, as well as new geometries of SIMS hardware (NanoSIMS) and techniques (time-of-flight SIMS). NanoSIMS allows a two to three order of magnitude reduction in sampling volume as a result of a reduced beam diameter, and time-of-flight SIMS allows the study of sample surfaces, and can provide data for elements concurrently. 相似文献
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Edward S. Grew Nikolai N. Pertsev Stanislav Vrána Martin G. Yates Charles K. Shearer Michael Wiedenbeck 《Contributions to Mineralogy and Petrology》1998,131(1):22-38
Kornerupine, (□,Fe,Mg)(Mg,Fe,Al)9(Si,Al,B)5 (O,OH,F)22, has been reported with talc in rocks from six localities worldwide, but only at Chilapila Hill in the Lufilian Arc, Zambia
do textural relationships imply that kornerupine (Krn) equilibrated with talc (Tlc) during a prograde metamorphic event at
T≈ 640 °C, P≈ 13 kbar; a prograde Krn + Tlc assemblage has also been reported from Mautia Hill, Tanzania (P ≤ 13 kbar). In order to estimate possible constraints on the stability range for the kornerupine + talc paragenesis in nature,
we constructed a P-T diagram in the model system MgO-Al2O3-SiO2-H2O (MASH) for seven phases quartz (Qtz), B-free kornerupine sensu stricto, anthophyllite (Ath), chlorite (Chl), cordierite
(Crd), kyanite (Ky), and talc. The minimum pressure for Krn + Tlc + Ky stability in MASH is close to that for Ky + Tlc stability,
i.e., 6–8 kbar, at T≤ 780 °C. However, in the natural system, B2O3 and Na2O are major constituents in Krn and orthoamphibole (Oam), respectively, and dravitic tourmaline (Tur) is widespread. The critical
assemblage alternative to Krn + Tlc in nature is Tur + Oam. The upper pressure limit of Tur + Ath is determined by the upper
pressure for anthophyllite: 7.7–10.5 kbar at 682–794 °C in the MgO-SiO2-H2O system (Chernosky et al. 1985, Am Mineral 70:223–236), and is undoubtedly higher in the presence of Na2O, CaO, and Al2O3. At three of the six localities, talc is a retrograde phase; nonetheless, it possibly equilibrated with kornerupine on the
retrograde path or during a later metamorphic event at P-T conditions appropriate for Ky + Tlc. At the sixth locality (Mulvoj, southwestern Pamir Mountains, Tajikistan), Krn is found
in the same thin section as talc and kyanite and all three minerals formed during a prograde metamorphic event at T≥ 650 °C, P near 7 kbar. However, Krn is restricted to a lens 4 to 6 mm thick of phlogopite + anthophyllite + Tur and it does not touch
either talc or kyanite. A reaction relating the Mulvoj and Chilapila Hill (Krn + Tlc + Ky + Qtz + Tur) parageneses is calculated
from compositions in the Mulvoj rock to be 0.40Tur + 2.55Ath + 1.33H2O + 0.27F = Krn + 2.16Tlc + 0.36B2O3 + 0.02Rutile + 0.19Na2O + 0.17CaO. Given the difference in metamorphic pressures estimated for Mulvoj and Chilapila Hill, Krn + Tlc is inferred
to be favored by increasing pressure as well as by low Na2O and CaO contents. Some FeO, F, Fe2O3, and BeO are present in measurable amounts in at least one of the phases in the Mulvoj and Chilapila Hill whiteschists (e.g.,
Krn contains 0.24–0.67 wt% BeO), but the effect of these constituents is subordinate to that of Na2O, CaO and B2O3. The Krn + Tlc could be a more important assemblage in B-bearing whiteschists than has been reported to date, particularly
at pressures where orthoamphibole is no longer stable.
Received: 21 April 1997 / Accepted: 13 October 1997 相似文献
23.
Sonia Tonarini Maddalena Pennisi Alessandra Adorni-Braccesi rea Dini Giorgio Ferrara Roberto Gonfiantini Michael Wiedenbeck Manfred Gröning 《Geostandards and Geoanalytical Research》2003,27(1):21-39
In 1999 the Istituto di Geoscienze e Georisorse (IGG), with the support of the International Atomic Energy Agency (IAEA), undertook the collection, preparation and distribution of eight geological materials intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials came from Italian sources and consist of three natural waters (Mediterranean seawater and two groundwaters) and five rocks and minerals (tourmaline, basalt, obsidian, limestone and clay). The solid materials were crushed, milled and mixed, in preparation for distribution. Extensive assays performed at the IGG on these materials demonstrated that their boron isotopic and chemical compositions are homogeneous.
Additional homogeneity tests were carried out on solid material fragments at the GeoForschungsZentrum Potsdam, with the specific objective of investigating the suitability of some of them for the calibration in situ of micro-analytical techniques. Two materials, B4 (tourmaline) and B6 (obsidian), proved to be isotopically homogeneous and may become excellent references for in situ microanalyses of boron isotopes.
The materials described here were used as the basis of a major laboratory intercomparison study and are now available for further distribution from either the IAEA (solid materials) or the IGG (waters). 相似文献
Additional homogeneity tests were carried out on solid material fragments at the GeoForschungsZentrum Potsdam, with the specific objective of investigating the suitability of some of them for the calibration in situ of micro-analytical techniques. Two materials, B4 (tourmaline) and B6 (obsidian), proved to be isotopically homogeneous and may become excellent references for in situ microanalyses of boron isotopes.
The materials described here were used as the basis of a major laboratory intercomparison study and are now available for further distribution from either the IAEA (solid materials) or the IGG (waters). 相似文献
24.
International Association of Geoanalysts'Protocol for the Certification of Geological and Environmental Reference Materials 总被引：2，自引：1，他引：2
Jean S. Kane Philip J. Potts Michael Wiedenbeck Jean Carignan Stephen Wilson 《Geostandards and Geoanalytical Research》2003,27(3):227-244
This protocol has been developed by the International Association of Geoanalysts to demonstrate procedures for the certification of geological and environmental reference materials to comply to the fullest extent possible with recommendations of the International Organisation for Standardisation (ISO Guide 35). A practical approach is described on the assumption that certifications will be normally be based on collaborative analysis programmes in which participating laboratories are preselected on the basis of performance in a proficiency testing programme or on the basis of other criteria of merit. 相似文献
25.
Michael Wiedenbeck 《Geostandards and Geoanalytical Research》2008,32(4):489-494
Secondary ion mass spectrometry (SIMS or ion microprobe) remains one of the most powerful tools available to the analytical geochemist. Despite the impressive progress witnessed by other competing laboratory methods over recent years, SIMS remains unsurpassed in its combination of small sampling volumes with low analytical uncertainties. Although the current SIMS analytical design has existed for over three decades, the period 2006–2007 saw significant advances in instrumentation, analytical methodology and, not least, the characterisation of new reference materials upon which all analyses depend. As of the end of 2007 the SIMS geoscience literature was reporting total sampling masses down to the 10 fg range, spatial resolution of better than 100 nm and uncertainties on major element isotope ratio determinations of better than ± 0.2‰ (1s). This article intends to synthesise the progress made by the geo‐SIMS community during this two year period and will also highlight some specific research results that were only possible due to the unique capabilities provided by SIMS. 相似文献
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Qi‐Chao Yang Klaus Peter Jochum Brigitte Stoll Ulrike Weis Dmitry Kuzmin Michael Wiedenbeck Heike Traub Meinrat O. Andreae 《Geostandards and Geoanalytical Research》2012,36(3):301-313
To test whether the silicate reference glasses BAM‐S005‐A and BAM‐S005‐B from BAM (The Federal Institute for Materials Research and Testing, Germany) are suitable materials for microanalysis, we investigated the homogeneity of these reference glasses using the microanalytical techniques EPMA, LA‐ICP‐MS and SIMS. Our study indicated that all major and most trace elements are homogeneously distributed at micrometre sampling scale in both types of glass. However, some trace elements (e.g., Cs, Cl, Cr, Mo and Ni) seem to be inhomogeneously distributed. We also determined the composition of BAM‐S005‐A and BAM‐S005‐B. The EPMA data of major elements confirmed the information values specified by the certificate. With the exception of Sr, Ba, Ce and Pb, our trace element data by LA‐ICP‐MS were also in agreement with the certified values within the stated uncertainty limits. The reasons for the discrepancy in these four elements are still unclear. In addition, we report new data for twenty‐two further trace elements, for which the concentrations were not certified. Based on our investigation, we suggest that both of these materials are suitable for many microanalytical applications. 相似文献
30.
Fernando?TornosEmail author Michael?Wiedenbeck Francisco?Velasco 《Mineralium Deposita》2012,47(5):483-499
Hydrothermal tourmaline is common in the iron oxide-copper-gold (IOCG) deposits of the Coastal Cordillera of Chile where it occurs as large crystals in the groundmass of magmatic-hydrothermal breccias, such as in the Silvita or Tropezón ore bodies, or as small grains in replacive bodies or breccia cement in the ore-bearing andesite, as seen at the Candelaria or Carola deposits. Tourmaline shows strong chemical zoning and has a composition of schorl–dravite with significant povondraite and uvite components. The observed boron isotope composition is fairly variable, between −10.4‰ and +6.0‰ with no major differences among the different deposits, suggesting a common genetic mechanism. The δ11B values are significantly lower than those of seawater or marine evaporites and very similar to those of younger porphyry copper deposits and volcanic rocks in the region, indicating that the boron has a common, likely magmatic, origin. The predominant boron source was ultimately dewatering of the subducting slab with a significant contribution derived from the overlying continental basement. The range of δ11B values is between those of the porphyry copper deposits and the porphyry tin deposits of the Andes, suggesting that the IOCG mineralization might be genetically related to fluids having more crustal contamination than the porphyry copper deposits; such an interpretation is at odds with current models that propose that the Andean IOCG deposits are related to juvenile melts or to the circulation of basinal brines. Furthermore, the obtained δ11B data are markedly different from those of the tourmaline in the Carajás IOCG district (Brazil), suggesting that IOCGs do not form by a unique mechanism involving only one type of fluids. 相似文献