2007
High temperature tu ultrahigh-temperature metamorpism related to multiple ultrapotassic intrusions:evidence from garnet-silimanite-cordierite kinzigite and garnet-orthopyroxene migmatites in the eastern part of the Moldanubian Zone (Bohemian Massif)
LEICHMANN, Jaromír; Milan NOVÁK; David BURIÁNEK and David BURGERBasic information
Original name
High temperature tu ultrahigh-temperature metamorpism related to multiple ultrapotassic intrusions:evidence from garnet-silimanite-cordierite kinzigite and garnet-orthopyroxene migmatites in the eastern part of the Moldanubian Zone (Bohemian Massif)
Name in Czech
Vysokoteplotní až ultravyokoteplotní metamorfoza spojená s polyfázovou ultrapotasickou intruzí:granáticko-silimanit-cordieritické kingigity a granát ortopyroxenické migmatitu z východní části moldanubika (český masív)
Authors
LEICHMANN, Jaromír (203 Czech Republic, guarantor, belonging to the institution); Milan NOVÁK (203 Czech Republic, belonging to the institution); David BURIÁNEK (203 Czech Republic, belonging to the institution) and David BURGER (203 Czech Republic, belonging to the institution)
Edition
Geologica Carpathica, Bratislava, 2007, 1335-0552
Other information
Language
English
Type of outcome
Article in a journal
Field of Study
10500 1.5. Earth and related environmental sciences
Country of publisher
Slovakia
Confidentiality degree
is not subject to a state or trade secret
Impact factor
Impact factor: 0.517
RIV identification code
RIV/00216224:14310/07:00020862
Organization unit
Faculty of Science
UT WoS
000251388100001
Keywords in English
Moldanubian Zone; Jihlava Pluton;mineral reactions;HT metamorphism;heat source;garnet-sillimanite rock;restite
Tags
Tags
International impact, Reviewed
Changed: 4/2/2011 14:59, prof. RNDr. Jaromír Leichmann, Dr. rer. nat.
In the original language
The garnet-sillimanite-cordierite kinzigite from Petrovice, Jihlava Pluton, Moldanubian Zone, Czech Republic has a hyperaluminous chemical composition. Its mineral assemblage consisting of garnet and prismatic sillimanite 1, relics of cordierite, hercynite, rutile 1, ilmenite and quartz, retrograde minerals - cordierite 11, fibrolitic sillimanite II and Ti-rich biotite and leucocratic portions with abundant K-feldspar, quartz and plagioclase which closely matches a restite. The prograde part of the reaction history was virtually obliterated and the mineral reactions: (1) Crd + Hrc = Grt + Sil; (2) Hrc+Qtz = Grt+Sil; (3) Grt+Sil+Qtz+L = Crd+Bt; (4) Grt+L = Crd+Bt+Qtz;, (5) Grt+Crd+L = Bt+Sil;, (6) Crd + L = Bt + Sil + Qtz took place during cooling. The relic assemblages cordierite+hercynite and hercynite+quartz, which represent a peak of metamorphism, are stable for P similar to 0.5 GPa at T > similar to 900 degrees C. The P-T conditions determined by geothermobarometry yield: T = 900 40 degrees C (garnet-ilmenite) and P = 0.73-0.49 GPa (spinel-garnet); concentrations of Zr in rutile I enclosed in garnet and sillimanite I yielded T = 840-970 degrees C. We assume, on the basis of the hyperaluminous chemistry and mineral assembly that the garnet-sillimanite-cordierite kinzigite from Petrovice is a restite, where a large portion of melt was lost from the rock. The sequence of mineral reactions, and garnet composition with low and constant Ca in the profile across the grain, indicate an isobaric cooling path. A moderate heat input from the Jihlava Pluton, manifested by garnet-orthopyroxene-cordierite migmatites developed at the direct contact of durbachites, supported by a local but large heat input of gabbro-monzogabbro associated directly with kinzigites seem probable heat sources. The chemical U-Pb ages of monazite 319 +/- 24 Ma from kinzigite, 329.8 +/- 9.5 Ma from gamet-orthopyroxene migmatites, and 335.8 +/- 6.9 Ma from gabbros are very close to U-Pb ages of zircon 335.2 +/- 0.5 Ma from durbachites (Kotkovd et al. 2003). They suggest a Variscan age of the HT (to UHT) metamorphism and support affiliation to the durbachite intrusions.
In Czech
Studium kinzigitů a Grt-Opx migmatitu ve východní části moldanubika. Intruze ultrapotassických hornin, restity.
Links
| GA205/03/0040, research and development project |
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| MSM0021622412, plan (intention) |
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