The Caucasus mountain belt has a complex tectono-thermal history that is as yet poorly understood due to the scarcity of reliable geochronological information. Here, we report new monazite and zircon data from the Dzirula massif in the southern Caucasus, which permit development of a model for Variscan LP-HT (low pressure-high temperature) metamorphism in this region. Data are presented for two key lithologies of the Dzirula massif: 1) a group of variably deformed granitoid (mainly granodioritic-tonalitic) rocks and 2) metapelitic LP-HT cordierite-biotitesillimanite migmatites and paragneisses. Electron-microprobe Th-U-total Pb monazite dating demonstrates that the LP-HT metamorphism in the Dzirula massif is Variscan, and occurred around 330 Ma. LA-ICP-MS zircon dating reveals that the granitoids include two different magmatic series. An older, mainly tonalitic, series is of Lower Cambrian age. Younger intrusions, including gabbros and diorites, but mainly tonalites and granodiorites, are Variscan in age. The older series show ductile deformation features and, along with the metapelites, experienced Variscan high-grade metamorphism that resulted in penetrative blastic recrystallization and anatexis. The younger series is generally undeformed, but often shows a magmatic foliation, and variable alteration under greenschist facies conditions. It is suggested that the Variscan intrusions facilitated the regional LP-HT metamorphic event at 330 to 340 Ma. Age and petrographic data from the Greater Caucasus imply a similar evolution as observed in the Dzirula massif. The Dzirula massif can thus be used as a proxy to model the evolution of the Caucasian Variscides.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.