How old is the Třebíč durbachitic Pluton? Reply to Comment on "Ultrapotassic magmatism in the heyday of the Variscan Orogeny: the story of the Třebíč Pluton, the largest durbachitic body in the Bohemian Massif" by Schaltegger et al.
Abstrakt
New re-evaluation of our U-Pb LA-ICP-MS data for strongly porphyritic melagranite 1322 from Petráveč (NE part of the Variscan ultrapotassic Třebíč Pluton, Moldanubian Zone of the Bohemian Massif) gives a weighted mean (207)Pb/(235)U age of 335 +- 3 Ma (2σ). This, together with our previous U-Pb LA-ICP-MS zircon age of 335 +- 3 Ma and CA-ID-TIMS zircon age of 335.127 +- 0.11 Ma newly acquired by Schaltegger et al. from the central part of the Třebíč body pin-point its emplacement age to 335 Ma.
Importantly, this datum constrains the oblique underthrusting of Brunia microcontinent, subvertical shortening and development of flat fabric in the Moldanubian Zone. Precise timing of the other Moldanubian durbachitic intrusions remains open to discussion.