Journal of Petrology Advance Access published online on December 10, 2004
Journal of Petrology, doi:10.1093/petrology/egh079
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 INSTITUT FÜR MINERALOGIE UND KRISTALLCHEMIE, UNIVERSITÄT STUTTGART, AZENBERGSTRASSE 18, D-70174 STUTTGART, GERMANY
* To whom correspondence should be addressed. A light-coloured, fine-grained eclogite sample from near the village of Hammerunterwiesenthal in the Erzgebirge (NW Bohemian Massif) preserves the low-variance mineral assemblage of garnet, omphacite, phengite, talc, amphibole, clinozoisite, quartz, rutile, and accessory phases. Porphyroblasts of amphibole, clinozoisite, and phengite formed during a late stage (III) of metamorphism. Paragonite joined the assemblage late in this stage (IIIb). The chemical zonation of the minerals was carefully studied. Various geothermobarometric methods were applied, especially involving phengite and talc. The constrained P-T path for the eclogite starts at about 480°C and 25 kbar (stage Ib), followed by a significant temperature rise (stage II) at slightly increasing pressure. At the peak P-T conditions of 720°C and 27 kbar, blastesis of amphibole, clinozoisite, and phengite was caused by infiltrating hydrous fluids. The resulting density reduction may have allowed buoyant uplift of the eclogite. Subsequently, significant cooling occurred at high pressures. Stage IIIb is characterized by P-T conditions around 520°C and 18 kbar at reduced water activities. This unusual late P-T evolution might explain the freshness of the eclogite, including the preservation of chemical zonation on the micrometre scale.
Received June 26, 2003
Accepted September 13, 2004
Article
A Low-Variance Mineral Assemblage with Talc and Phengite in an Eclogite from the Saxonian Erzgebirge, Central Europe, and its P-T Evolution
2 LANDESAMT FÜR GEOWISSENSCHAFTEN UND ROHSTOFFE BRANDENBURG, STAHNSDORFER DAMM 77, D-14532 KLEINMACHNOW, GERMANY
H.-J. MASSONNE, E-mail: h-j.massonne{at}mineralogie.uni-stuttgart.de
![]()
Abstract ![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
Y.-F. Zhu, H.-J. Massonne, and M.-F. Zhu Petrology of low-temperature, ultrahigh-pressure marbles and interlayered coesite eclogites near Sanqingge, Sulu terrane, eastern China Mineralogical Magazine, August 4, 2009; 73(2): 307 - 332. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Gross, M. Burchard, H.-P. Schertl, and W. V. Maresch Common high-pressure metamorphic history of eclogite lenses and surrounding metasediments: a case study of calc-silicate reaction zones (Erzgebirge, Germany) European Journal of Mineralogy, October 1, 2008; 20(5): 757 - 775. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Vega-Granillo, O. Talavera-Mendoza, D. Meza-Figueroa, J. Ruiz, G. E. Gehrels, M. Lopez-Martinez, and J. C. de la Cruz-Vargas Pressure-temperature-time evolution of Paleozoic high-pressure rocks of the Acatlan Complex (southern Mexico): Implications for the evolution of the Iapetus and Rheic Oceans Geological Society of America Bulletin, September 1, 2007; 119(9-10): 1249 - 1264. [Abstract] [Full Text] [PDF] |
||||


