SIMS analysis of chlorine in metasomatized upper-mantle rocks (Abstract/Comunicazione in atti di convegno)

Type
Label
  • SIMS analysis of chlorine in metasomatized upper-mantle rocks (Abstract/Comunicazione in atti di convegno) (literal)
Anno
  • 2007-01-01T00:00:00+01:00 (literal)
Alternative label
  • OTTOLINI L.; LE FEVRE B. (2007)
    SIMS analysis of chlorine in metasomatized upper-mantle rocks
    in EMAS 2007, 10th Eur. Workshop on Modern Developments and Applications in Microbeam Analysis, Antwerp (Belgium), May 6-10 (2007)
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • OTTOLINI L.; LE FEVRE B. (literal)
Pagina inizio
  • 290 (literal)
Pagina fine
  • 290 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#titoloVolume
  • Book of Abstracts (literal)
Note
  • Abstract (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • OTTOLINI L. 1); LE FEVRE B. 2). 1) CNR-Istituto di Geoscienze e Georisorse (IGG), Pavia, Italy; 2) GEOTOP-UQAM-McGill, Montreal, Qc, H3C 3P8, Canada; (literal)
Titolo
  • SIMS analysis of chlorine in metasomatized upper-mantle rocks (literal)
Abstract
  • In spite of the importance of chlorine as a geochemical tracer, Cl data on mantle rocks are nowadays rather scarce mainly due to analytical difficulties. Techniques involving sample dissolution and/or fusion as well as non-destructive bulk techniques have been used for Cl determination in silicates, but they need rather high amount of material, which, in most cases, hampers the investigation of single minerals. Electron microprobe is generally employed to measure Cl contents on the level of several hundreds of ppm, whereas lower Cl concentrations (few tens ppm) are not routine for EMPA. The SIMS technique that affords for low detection limits over a large mass range and a good spatial resolution represents a powerful tool to address some of the main questions still open about Cl behaviour in the Earth mantle. In this work we report and discuss the SIMS data for Cl obtained on upper-mantle peridotites and xenoliths affected by various metasomatic processes as a result of the ion exchange between minerals and solid rocks, and migrating fluid phases. The samples here investigated are represented by peridotites BM90-6 (Balmuccia, Western Alps, Italy) and LH12 (Lherz, Eastern Pyrénées, France); pre-rift peridotite Z2070 (Zabargad Island, Red Sea); xenoliths from alkaline lavas Z7 and RP68 (Massif Central, France). An improvement in our analytical procedure at the ion microprobe (Cameca IMS 4f) at CNR-IGG (Pavia) allowed for the quantification of very low amounts of Cl (down to few ppm by weight). It allowed also for the measurement of other relevant trace elements at the same spot during the analytical run. Our experimental set up included a 16O- primary beam (? 15-?m Ø) and energy-filtered secondary-ions that were monitored in positive mode at low mass resolving power (M/?M = 600). We derived some interesting information about the Cl distribution inter- and intra-mineral silicate phases: olivine, orthopyroxene, clinopyroxene and amphibole (when present), and studied the correlation between chlorine and other important geochemical tracers, i.e., boron and lithium. The in-situ analysis of Cl by SIMS in mineral phases resulted to have the potential for opening a new window on what \"upper-mantle metasomatism\" really means. (literal)
Prodotto di
Autore CNR

Incoming links:


Prodotto
Autore CNR di
data.CNR.it