Record details

Title
    Cretaceous alkaline lamprophyres from northeastern Czech Republic: geochemistry and petrogenesis
Statement of responsibility
    Jaroslav Dostál, J. V. Owen
Author
    Dostál, Jaroslav
    Owen, J. V.
Language
    anglicky
Source title - serial
    Geologische Rundschau
Vol./nr.
    Vol. 87, no. 1
Pages
    p. 67-77
Year
    1998
Notes
    1 obr., 7 diagr., 3 tab., 2 s.bibl.
    Zkr. název ser.: Geol. Rdsch.
Subject group
    alkalický typ
    chemismus hornin
    flyšové pásmo Západních Karpat
    geochemie izotopická
    izotopy Nd
    izotopy Sr
    křída
    lamprofyry
    petrogeneze
    těšinit
    vzácné zeminy
Geographical name
    Bludovice (Nový Jičín)
    ČR-Morava
    Hodslavice (Nový Jičín)
    Kojetín (Nový Jičín)
    Řepiště (Frýdek-Místek)
    Staříč (Frýdek-Místek)
    Straník (Nový Jičín)
    Veřovice (Nový Jičín)
    Žilina (Nový Jičín)
Keyword
    Alkaline
    Cretaceous
    Czech
    Geochemistry
    Lamprophyres
    Northeastern
    Petrogenesis
    Republic
Abstract (in english)
   he northeast part of the Czech Republic (Moravia) and the adjoining part of Poland host a 100-km-long and 15-to 25-km-wide belt containing numerous isolated bodies (mainly sills) of laprophyre of Lower Cretaceous age. The lamprophyres range from mafic (melanocratic) to variants. Mineralogically, they are characterized by compositionally zoned kaersutite phenocrysts, biotite and high Al-ti salitic to diopsidic clinopyroxene. The laprophyres are typically alkaline as shown ba high contents of P2O5, TiO2, alkalies and incompatible trace elements such as light REE, Zr, Nb, Y. Ba and Sr, and by high Ti/V (50) and chondrite-normalized (La/Yb)B (8-25) ratios. They resemble alkali basalts, basanites and nephelinites. Major element composition and trace element patterns and Nd-Sr isotopic values ( Nd ca. +5.5 to +6.6 and Sr ca.
   -9.5 to -24.0) indicate that the lamprophyric magma was derived from a mantle source that was compositionally similar to the source of ocean island basalts with HIMU affinities and some continental extension-related alkali basaltic suites. The lamprophyres do not show any subduction imprint. They were generated in the garnet stability field by a variable degree of melting. Evolved lamprophyres were formed by clinopyroxene-dominated fractional crystallization of mafic lamprophyric magma. The lamprophyres are interpreted to have been emplaced along conduits formed during the formation of a basin/graben structure in the Early Cretaceous
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    3. 1. 2008
Import date
    8. 8. 2012