Neoproterozoic to Early Cambrian history of an active plate margin in the Teplá–Barrandian unit—a correlation of U–Pb isotopic- dilution-TIMS ages (Bohemia, Czech Republic)

• Main Authors: W. Dörr A, G. Zulauf B, J. Fiala C, W. Franke A, Z. Vejnar C
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2001
• Subjects: U–Pb analyses; Zircons; Age correlation; Cadomian Orogeny; Bohemian Massif; Morena; Newfoundland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.470.6081; http://www.uni-giessen.de/fbr08/geolith/pdf-homepage/Tecton2002D%F6rr.pdf

The Teplá–Barrandian unit (TBU) of the Bohemian Massif shared a common geological history throughout the Neoproterozoic and Cambrian with the Avalonian–Cadomian terranes. The Neoproterozoic evolution of an active plate margin in the Teplá–Barrandian is similar to Avalonian rocks in Newfoundland, whereas the Cambrian transtension and related calc-alkaline plutons are reminiscent of the Cadomian Ossa–Morena Zone and the Armorican Massif in western Europe. The Neoproterozoic evolution of the Teplá–Barrandian unit fits well with that of the Lausitz area (Saxothuringian unit), but is significantly distinct from the history of the Moravo–Silesian unit. The oldest volcanic activity in the Bohemian Massif is dated at 609+17/19 Ma (U–Pb upper intercept). Subduction-related volcanic rocks have been dated from 585F7 to 568F3 Ma (lower intercept, rhyolite boulders), which pre-dates the age of sedimentation of the Cadomian flysch (Štěchovice Group). Accretion, uplift and erosion of the volcanic arc is documented by the Neoproterozoic Dobřı́s ̌ conglomerate of the upper part of the flysch. The intrusion age of 541+7/8 Ma from the Zgorzelec granodiorite is interpreted as a minimum age of the Neoproterozoic sequence. The Neoproterozoic crust was tilted and subsequently early Cambrian intrusions dated at 522F2 Ma (Těšovice granite), 524F3 Ma (Všepadly granodiorite), 523F3 Ma (Smržovice tonalite), 523F1 Ma (Smržovice gabbro) and