A Clockwise P-T Path from the Variscan Basement of the Tisza Unit, Pannonian Basin, Hungary

P. Árkai, Péter Horväth, G. Nagy

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The polymetamorphic basement of the Tisza Unit forms a detached fragment of the Variscan European foreland of the Neotethyan realm. A clockwise evolution path of a gneiss-amphibolite complex of the Tisza Unit was reconstructed, investigating the polymetamorphic rocks of the borehole Baksa-2, SE Transdanubia, Hungary. The results obtained by microstructural and mineral paragenetic observations, mineral chemical analyses, and thermobarometric calculations define a P-T loop which suggests a complex Variscan polyphase model rather than a pre-Variscan - Variscan polycyclic one. The early part of the prograde path with kyanite is characterized by T-P conditions of 480±50°C and 470±70 MPa, respectively. The metamorphism reached its peak at 660±25°C and 750±50 MPa, when both kyanite and staurolite were stable. This metamorphic climax was followed by a nearly isothermal decompression to 440±20 MPa at 650±40°C. This event is marked by the presence of sillimanite and a second generation of garnet, and is closely related to the collisional Variscan granitoid magmatism observed in considerable parts of the Tisza Unit. In amphibolites intercalated with gneisses, only this last event was preserved, providing T-P estimates of ca. 650-690°C / 400-500 MPa. The present paper provides the first demonstration of a continuous, clockwise P-T path from the metamorphic basement of the Hungarian part of the Tisza Unit.

Original languageEnglish
Pages (from-to)109-117
Number of pages9
JournalGeologia Croatica
Volume52
Issue number2
Publication statusPublished - 1999

Fingerprint

Hercynian orogeny
basin
kyanite
staurolite
climax
P-T conditions
sillimanite
mineral
decompression
amphibolite
granitoid
gneiss
magmatism
garnet
metamorphism
borehole
rock

Keywords

  • Amphibolite
  • Geothermobarometry
  • Gneiss
  • Hungary
  • Pannonian basin
  • Tisza unit
  • Variscan regional metamorphism

ASJC Scopus subject areas

  • Geology

Cite this

A Clockwise P-T Path from the Variscan Basement of the Tisza Unit, Pannonian Basin, Hungary. / Árkai, P.; Horväth, Péter; Nagy, G.

In: Geologia Croatica, Vol. 52, No. 2, 1999, p. 109-117.

Research output: Contribution to journalArticle

@article{eb965c55979a4560a796aa3bcc6a51e6,
title = "A Clockwise P-T Path from the Variscan Basement of the Tisza Unit, Pannonian Basin, Hungary",
abstract = "The polymetamorphic basement of the Tisza Unit forms a detached fragment of the Variscan European foreland of the Neotethyan realm. A clockwise evolution path of a gneiss-amphibolite complex of the Tisza Unit was reconstructed, investigating the polymetamorphic rocks of the borehole Baksa-2, SE Transdanubia, Hungary. The results obtained by microstructural and mineral paragenetic observations, mineral chemical analyses, and thermobarometric calculations define a P-T loop which suggests a complex Variscan polyphase model rather than a pre-Variscan - Variscan polycyclic one. The early part of the prograde path with kyanite is characterized by T-P conditions of 480±50°C and 470±70 MPa, respectively. The metamorphism reached its peak at 660±25°C and 750±50 MPa, when both kyanite and staurolite were stable. This metamorphic climax was followed by a nearly isothermal decompression to 440±20 MPa at 650±40°C. This event is marked by the presence of sillimanite and a second generation of garnet, and is closely related to the collisional Variscan granitoid magmatism observed in considerable parts of the Tisza Unit. In amphibolites intercalated with gneisses, only this last event was preserved, providing T-P estimates of ca. 650-690°C / 400-500 MPa. The present paper provides the first demonstration of a continuous, clockwise P-T path from the metamorphic basement of the Hungarian part of the Tisza Unit.",
keywords = "Amphibolite, Geothermobarometry, Gneiss, Hungary, Pannonian basin, Tisza unit, Variscan regional metamorphism",
author = "P. {\'A}rkai and P{\'e}ter Horv{\"a}th and G. Nagy",
year = "1999",
language = "English",
volume = "52",
pages = "109--117",
journal = "Geologia Croatica",
issn = "1330-030X",
publisher = "Institute of Geology",
number = "2",

}

TY - JOUR

T1 - A Clockwise P-T Path from the Variscan Basement of the Tisza Unit, Pannonian Basin, Hungary

AU - Árkai, P.

AU - Horväth, Péter

AU - Nagy, G.

PY - 1999

Y1 - 1999

N2 - The polymetamorphic basement of the Tisza Unit forms a detached fragment of the Variscan European foreland of the Neotethyan realm. A clockwise evolution path of a gneiss-amphibolite complex of the Tisza Unit was reconstructed, investigating the polymetamorphic rocks of the borehole Baksa-2, SE Transdanubia, Hungary. The results obtained by microstructural and mineral paragenetic observations, mineral chemical analyses, and thermobarometric calculations define a P-T loop which suggests a complex Variscan polyphase model rather than a pre-Variscan - Variscan polycyclic one. The early part of the prograde path with kyanite is characterized by T-P conditions of 480±50°C and 470±70 MPa, respectively. The metamorphism reached its peak at 660±25°C and 750±50 MPa, when both kyanite and staurolite were stable. This metamorphic climax was followed by a nearly isothermal decompression to 440±20 MPa at 650±40°C. This event is marked by the presence of sillimanite and a second generation of garnet, and is closely related to the collisional Variscan granitoid magmatism observed in considerable parts of the Tisza Unit. In amphibolites intercalated with gneisses, only this last event was preserved, providing T-P estimates of ca. 650-690°C / 400-500 MPa. The present paper provides the first demonstration of a continuous, clockwise P-T path from the metamorphic basement of the Hungarian part of the Tisza Unit.

AB - The polymetamorphic basement of the Tisza Unit forms a detached fragment of the Variscan European foreland of the Neotethyan realm. A clockwise evolution path of a gneiss-amphibolite complex of the Tisza Unit was reconstructed, investigating the polymetamorphic rocks of the borehole Baksa-2, SE Transdanubia, Hungary. The results obtained by microstructural and mineral paragenetic observations, mineral chemical analyses, and thermobarometric calculations define a P-T loop which suggests a complex Variscan polyphase model rather than a pre-Variscan - Variscan polycyclic one. The early part of the prograde path with kyanite is characterized by T-P conditions of 480±50°C and 470±70 MPa, respectively. The metamorphism reached its peak at 660±25°C and 750±50 MPa, when both kyanite and staurolite were stable. This metamorphic climax was followed by a nearly isothermal decompression to 440±20 MPa at 650±40°C. This event is marked by the presence of sillimanite and a second generation of garnet, and is closely related to the collisional Variscan granitoid magmatism observed in considerable parts of the Tisza Unit. In amphibolites intercalated with gneisses, only this last event was preserved, providing T-P estimates of ca. 650-690°C / 400-500 MPa. The present paper provides the first demonstration of a continuous, clockwise P-T path from the metamorphic basement of the Hungarian part of the Tisza Unit.

KW - Amphibolite

KW - Geothermobarometry

KW - Gneiss

KW - Hungary

KW - Pannonian basin

KW - Tisza unit

KW - Variscan regional metamorphism

UR - http://www.scopus.com/inward/record.url?scp=0005991797&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0005991797&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0005991797

VL - 52

SP - 109

EP - 117

JO - Geologia Croatica

JF - Geologia Croatica

SN - 1330-030X

IS - 2

ER -