Record details

Title
    Shock-induced phenomena in limestones in the quarry near Ronheim, the Ries Crater, Germany
Statement of responsibility
    Roman Skála
Author
    Skála, Roman
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Bulletin of the Czech Geological Survey-Věstník Českého geologického ústavu
    Věstník Českého geologického ústavu (Bulletin of the Czech Geological Survey)
Vol./nr.
    Roč. 77, č. 4
Pages
    8
    s. 313-320
Year
    2002
Notes
    6 obr., 3 fot., 3 tab., 32 bibl.
    il.
    Zkr. název ser.: Věst. Čes. geol. Úst. (Bull. Czech geol. Surv.)
Subject group
    difrakce rentgenová
    jevy šokové
    kalcit
    kráter impaktní
    metamorfóza šoková
    mřížkové parametry
    spektrometrie IR
    vápenec
Thesaurus term
    impact structures, shock metamorphism, limestone, calcite, cell dimensions, Ries Crater, X-ray diffraction, infra-red spectroscopy
Geographical name
    Ronheim (SRN-Bayern)
    SRN-Bayern
Keyword
    Crater
    Germany
    Limestones
    Near
    Phenomena
    Quarry
    Ries
    Ronheim
    Shock-induced
Abstract (in english)
   Shock-induced effects in Malmian limestone sequences sampled in the quarry near Ronheim in the southeastern rim of the Ries impact structure in Germany were studied.

   Shock-induced effects in Malmian limestone sequences sampled in the quarry near Ronheim in the southeastern rim of the Ries impact structure in Germany were studied using electron microscopy with local chemical microanalysis, X-ray powder diffraction, IR spectroscopy, stable isotope study and MAS NMR spectroscopy. The most pronounced deformation observed is a pervasive brecciation resulting in the formation of parautochthonous to completely allochthonous limestone megablocks (so-called "Schollen") on a megascopic scale. On a macroscopic scale, this process gives rise to monomict breccias (so-called "Gries"). The applied analytical methods also revealed the damage of the limestones on submicroscopic and atomic scales. The peaks in X-ray diffraction patterns are broadened due to increased domain size and microstrain. Bands in the MAS NMR spectra show also broadening - most probably due to the random shifts of (CO3)2- ions in the calcite crystal structure.
   The overall degree of shock-induced solid-state deformation is, however, low. No decomposition, stable isotope fractionation or melting occurring at high degrees of shock metamorphism were found. This allows to speculate on fast attenuation of peak shock pressure towards the crater rim in the most superficial regions of the target. Also the role of brittle behaviour of carbonates occurring in a relatively thin layer deposited over more competent crystalline basement revealing considerably higher degrees of shock metamorphism in large volumes must be taken into account in interpreting the low degree of shock metamorphism in the studied limestones
Contributor
    Česká geologická služba
Contributor code
    ČGS (RIV)
    ČGS (UNM)
Source format
    R
    U
Entered date
    10. 7. 2007
Import date
    8. 8. 2012
    15. 10. 2014