AGE OF THE EARLY PALEOZOIC GRANITOID MAGMATISMIN THE CENTRAL PART OF THE BUREYA CONTINENTAL MASSIF, CENTRAL ASIAN FOLD BELT

Abstract

The article presents new age data on the ‘key’ Early Paleozoic igneous complexes located in the central part of the Bureya continental massif of the Central Asian Fold Belt. Porphyroblastic quartz monzonites of the Kivili complex are dated to 453±2 Ma. The age of gneissic granites of the Sularin complex is ~481 Ma. The Sm-Nd isotope stu­dies show that Late Ordovician quartz monzonites were formed mainly from crustal sources with Paleoproterozoic Nd model isotopic ages. Both ancient (Paleoproterozoic?) and younger sources were involved in the formation of Cambrian granites. Our data, as well as previously published materials, suggest several stages of the Early Paleozoic magmatism in the evolution of the Bureya continental massif: ~541, ~504–500, ~487, ~474 and ~453 Ma. Early Paleozoic magmatism developed under a similar scenario in the Jiamusi continental massif. In addition to the synchronism of Neoproterozoic magmatism within these continental massifs, this feature testifies to their common geological history.

Keywords

• bureya continental massif
• central asian fold belt
• granitoid magmatism
• u-pb and u-th-pb geochronology
• early paleozoic
• source