Record details

Title
    On Li-bearing micas: estimating Li from electron microprobe analyses and an improved diagram for graphical representation
Statement of responsibility
    Gerhard Tischendorf, Bärbel Gottesmann, Hans-Jürgen Förster, Robert B. Trumbull
Author
    Förster, Hans-Jürgen, 1948-
    Gottesmann, Bärbel
    Tischendorf, Gerhard
    Trumbull, Robert B.
Language
    anglicky
Source title - serial
    Mineralogical magazine
Vol./nr.
    Vol. 61, no. 6
Pages
    p. 809-834
Year
    1997
Notes
    13 obr., 4 tab., 4 s.bibl.
    Zkr. název ser.: Mineral. Mag.
Subject group
    krušnohorský pluton
    krystalochemie
    lithium
    mikroanalýza elektronová
    slídy
    zpracování dat
Geographical name
    Cínovec (Teplice)
    ČR-Čechy
    SRN
Keyword
    Analyses
    Diagram
    Electron
    Estimating
    Graphical
    Improved
    Li
    Li-bearing
    Micas
    Microprobe
    Representation
Abstract (in english)
   Lithium may constitute an essential element in micas, yet it cannot be detected by the electron microprobe. Since Li is critical for correctly classifying micas and properly calculating their formulae, several methods have been proposed to overcome this analytical deficiency. We offer empirical relationships between Li2 O and Si O2, MgO, F, and Rb in trioctahedral micas, and between Li2 O and F as well as Rb in dioctahedral micas. The resultant regression equations enable lithium contents to be sufficiently well estimated from EPM analyses within the range of validity discussed. Secondly, we introduce an easy to handle, new diagram with the axis variables [Mg-Li] and [Fe tot+Mn+Ti-Al VI] for graphical representation and discuss its scientific rationale.
   Being based on absolute abundances of cations in the octahedral layer, the diagram provides a simple means to classify micas in terms of composition and octahedral site occupancy, and it also allows compositional relationships between Li-bearing and Li-free mica varieties as well as between trioctahedral and dioctahedral micas to be displayed on a single two-dimensional diagram
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    21. 2. 2008
Import date
    8. 8. 2012