DETRITAL ZIRCON GEOCHRONOLOGY AND PROVENANCE OF THE PROTEROZOIC QUARTZ-RICH METASEDIMENTS OF THE MAZOWSZE DOMAIN: SOURCE AREAS AND REGIONAL CORRELATION

Drilling at Mońki IG-2 and Zabiele IG-1 in the Mazowsze domain has intersected mature quartz-rich metasedimentary rocks belonging to the basement of NE Poland, described so far as a Biebrza complex. The geochemical composition of these rocks is characteristic of a passive margin. The subarkose–quartz arenite underwent low-T metamorphism, but preserved textures typical for the fluvial sediments. The detrital material in range 1.68–2.11 Ga was provided from surrounding late Paleoproterozoic margins of the Fennoscandia and Sarmatia. The maximum depositional age probably did not exceed 1.6 Ga. A previously suggested correlation with Mesoproterozoic molasse-type deposits of the Jotnian formation has not been confirmed. It seems more likely that the sediments formed after Fennoscandia-Sarmatia collision (i.e. termination of Svecofennian orogeny) but before denudation of the Mesoproterozoic Mazury AMCG intrusions.