TY - JOUR
T1 - Gneiss domes, metamorphic core complexes, and wrench zones
T2 - Thermal and structural evolution of the Niǧde Massif, central Anatolia
AU - Whitney, Donna L.
AU - Teyssier, Christian
AU - Heizler, Matthew T.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2007/10
Y1 - 2007/10
N2 - The Niǧde Massif, a migmatite-cored structural dome in south central Turkey, was metamorphosed, deformed, intruded, and exhumed in an oblique tectonic regime involving a switch from transpression (prograde metamorphism) to transtension (exhumation). An 80 Ma history of transpression and transtension is recorded in metamorphic rocks of the massif, and the last ∼50 Ma are recorded in both basement and overlying basin deposits. Niǧde metamorphic rocks record a high-temperature, top-to-north, syntranspression ductile fabric that was overprinted by lower-grade, top-to-south, syntranstension ductile shear zones. The 40Ar/39Ar data for hornblende, muscovite, and biotite document rapid Late Cretaceous cooling, with the oldest Ar homblende ages (88-79 Ma) overlapping UPb ages in monazite and zircon (92-78 Ma). Muscovite Ar ages are dominantly 81-79 Ma, suggesting a short time between crystallization of high-temperature metamorphic rocks and their cooling. Biotite Ar ages are 79-74 Ma, with the exception of disturbed samples from the eastern margin of the massif and from Eocene granitic stocks in the dome core. The eastern margin, adjacent to the sinistral Central Anatolian Fault Zone, records another cycle of burial and exhumation that overprinted earlier fabrics and disturbed isotopic systems. These two cycles of burial-exhumation took place repeatedly along the same zone; this may be characteristic of highly oblique tectonic regimes. In the Niǧde Massif, burial and exhumation became more localized and of lower amplitude over time, suggesting stabilization of the crust.
AB - The Niǧde Massif, a migmatite-cored structural dome in south central Turkey, was metamorphosed, deformed, intruded, and exhumed in an oblique tectonic regime involving a switch from transpression (prograde metamorphism) to transtension (exhumation). An 80 Ma history of transpression and transtension is recorded in metamorphic rocks of the massif, and the last ∼50 Ma are recorded in both basement and overlying basin deposits. Niǧde metamorphic rocks record a high-temperature, top-to-north, syntranspression ductile fabric that was overprinted by lower-grade, top-to-south, syntranstension ductile shear zones. The 40Ar/39Ar data for hornblende, muscovite, and biotite document rapid Late Cretaceous cooling, with the oldest Ar homblende ages (88-79 Ma) overlapping UPb ages in monazite and zircon (92-78 Ma). Muscovite Ar ages are dominantly 81-79 Ma, suggesting a short time between crystallization of high-temperature metamorphic rocks and their cooling. Biotite Ar ages are 79-74 Ma, with the exception of disturbed samples from the eastern margin of the massif and from Eocene granitic stocks in the dome core. The eastern margin, adjacent to the sinistral Central Anatolian Fault Zone, records another cycle of burial and exhumation that overprinted earlier fabrics and disturbed isotopic systems. These two cycles of burial-exhumation took place repeatedly along the same zone; this may be characteristic of highly oblique tectonic regimes. In the Niǧde Massif, burial and exhumation became more localized and of lower amplitude over time, suggesting stabilization of the crust.
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U2 - 10.1029/2006TC002040
DO - 10.1029/2006TC002040
M3 - Article
AN - SCOPUS:37549044249
SN - 0278-7407
VL - 26
JO - Tectonics
JF - Tectonics
IS - 5
M1 - TC5002
ER -