Record details

Title
    Formation and Evolution of High-Pressure Leucogranulites: Experimental Constrains and Unresolved Issues
Statement of responsibility
    Jana Kotková, Simon L. Harley
Author
    Harley, Simon L.
    Kotková, Jana, 1963-
Language
    anglicky
Source title - serial
    Physics and chemistry of the Earth. Part A
Vol./nr.
    Vol. 24, no. 3
Pages
    p. 299-304
Year
    1999
Notes
    4 diagr., 33 bibl.
    il.
Subject group
    granáty
    granulit
    krušnohorské krystalinikum
    metamorfóza vysokotlaká
    moldanubikum
    protolit
    původ korový
    studie experimentální
    tavení
    vzácné zeminy
    zonálnost krystalu
Geographical name
    Blanský les
    ČR-Čechy
    Lišov (České Budějovice)
    Prachatice
Keyword
    Constrains
    Evolution
    Experimental
    Formation
    High-Pressure
    Issues
    Leucogranulites
    Unresolved
Abstract (in english)
   High-pressure (HP) leucogranulites of the Bohemian Massif are intrepreted as the metamorphosed equivalents of HP leucogranites produced by deep crustal melting. This is supported by their preserved mineral assemblages (Grt-Ky-mesoperthite), bulk rock chemistry, P-T estimates, and garnet and accessory phase trace element abundances. Following melting and peak metamorphism, the leucogranulites have been exhumed from lower crustal depths to their present position at the highest structural leve of the Gföhl Nappe. The nearisothermal decompression (ITD) P-T path and available geochronological data imply high exhumation rates. The dry character of the leucogranulites reflects the water-undersaturated conditions that prevailed during formation of the precursor leucogranitic melts and their subsequent recrystallization in the middle and lower crust.
   Compositions of the leucogranulites are displaced towards the Qz-Or join in the Qz-Ab-Or ternary diagram, which corresponds to experimental results for water undersaturated melting. Trace element and REE abundanced in whole rocks, garnets and accessory phases are consistent with muscovite and biotite dehydration melting coupled with K-feldspar fractionation or separation as the principal controls of these HP leucogranite melts are evaluated in the light of available experimental data for water-saturated and dry melting of crustal rocks
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    28. 1. 2008
Import date
    8. 8. 2012