Th-U-Pb age pattern in metamorphic monazites from the Variscan high pressure units in the Saxothuringian Zone (Saxony, NE-Bavaria)

• Applicant: Professor Dr. Bernhard Schulz
• Subject Area: Mineralogy, Petrology and Geochemistry ; Palaeontology
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 280870545

The Allochthonous Domain of the Saxothuringian Zone is characterised by geological units with ultrahigh temperature, ultrahigh pressure, high pressure, medium pressure and low pressure metamorphism. The pressure-temperature (P-T)-paths of the units recorded a Carboniferous continental collision in the course of the Variscan orogeny. Th-U-Pb dating of monazite ((LREE, Th, U, Si, Ca)PO4) by electron microprobe allows to resolve several thermal events in metamorphic terrains. In this project, monazite and garnet in thin sections of micaschists and gneisses will be characterised by automated SEM-based methods. By the in situ analysis of monazite in microstructures, analysis of Y in garnet by LA-ICPMS and geothermobarometry, distinct segments of the P-T paths can be related to time sections (Petrochronology). Thermal events previous and posterior to a garnet crystallisation can be identified by the monazite age distribution pattern from several samples of a geological unit. In combination to the P-T paths, the monazite age distribution pattern allow the temporal-spatial reconstruction of the continent collision with nappe stacking and the transition to intense Carboniferous-Permian magmatism.

• DFG Programme: Research Grants
• International Connection: Austria
• Cooperation Partner: Professor Dr. Fritz Finger
• Co-Investigators: Professor Dr. Ulrich Schüßler; Privatdozent Dr. Eckhard Stein