Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
  Geological Magazine   Don't get GSW? Talk to your librarian.
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geological Magazine; July 2006; v. 143; no. 4; p. 491-508; DOI: 10.1017/S0016756806001981
© 2006 Cambridge University Press (CUP)
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by SLOBODNÍK, M.
Right arrow Articles by KEPPENS, E.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Variscan veins: record of fluid circulation and Variscan tectonothermal events in Upper Palaeozoic limestones of the Moravian Karst, Czech Republic

M. SLOBODNÍK*,*, PH. MUCHEZ{dagger}, J. KRÁL{ddagger} and E. KEPPENS§

* Institute of Geological Sciences, Masaryk University, Kotlárská 2, 611 37 Brno, Czech Republic
{dagger} Afd. Fysico-chemische Geologie, Katholieke Universiteit Leuven, Celestijnenlaan 200C, B-3001 Leuven, Belgium
{ddagger} Geological Survey of Slovak Republic, Mlynská dolina 1, 817 04 Bratislava, Slovak Republic
§ Laboratorium voor Geochronology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Belgium

* Author for correspondence: marek{at}sci.muni.cz

Numerous Variscan syntectonic calcite veins cross-cut Palaeozoic rocks in the Moravian Karst. A structural, petrographic and stable isotopic analysis of the calcite veins and a microthermometric study of fluid inclusions in these vein cements have been carried out to determine the origin of the Variscan fluids and their migration during burial and deformation. The isotopic parameters of white (older, more deformed) and rose (younger) calcites are: 87Sr/86Sr is between 0.7078 and 0.7082 (white) and 0.7086 (rose), {delta}18O is between +17.7 and +26.1 (white) and between +14.8 and +20.7 {per thousand} SMOW (rose), {delta}13C ranges from +0.1 to +2.5 (white) and from –0.3 to +1.6 {per thousand} V-PDB (rose). The isotopic signatures point to precipitation in an older fluid system buffered by the host rock (white calcites) and to an open, younger fluid-dominated system (rose calcites). Parent fluids (H2O–NaCl system) had salinities between 0.35 and 17.25 eq. wt % NaCl. The pressure-corrected and confined homogenization temperatures suggest formation of the calcite veins from a fluid with a temperature between 120 and 170 °C, a pressure of 300–880 bar at a depth between 2.1 and 3.2 km. The fluids were most likely confined to a particular sedimentary bed as a bed-scale fluid migration (white older calcite veins) or, later, to a pile of Palaeozoic sediments as a stratigraphically restricted fluid flow (rose younger calcite veins). The low temperatures and pressures during precipitation of calcites, which took place close to a peak of burial/deformation, confirm the distal position of the Moravian Karst region within the Variscan orogen.

Key Words: Palaeozoic • calcite • veins • syntectonic processes • fluid dynamics






JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Cambridge University Press (CUP)