A preliminary reassessment of the Siberian cratonic basement with new U-Pb-Hf detrital zircon data

Abstract

New and compiled U-Pb-Hf detrital zircon data from provincial Meso- to Neoproterozoic sedimentary basins characterize the buried crust of the Siberian cratonic basement. Along the northwestern Siberian cratonic margin (Turukhansk uplift, Yenisei Ridge) the basins accumulated predominantly 2.6–2.5 Ga zircons with εHf (T) values of +3 to −7, and 1.9–1.85 Ga zircons, characterized by εHf (T) values of −10 to +10. In the southwestern part of the craton (Prisayan uplift), similar 1.9–1.85 Ga and older Archean zircons are common, whereas in the eastern part older Paleoproterozoic zircons of 2.15–1.95 Ga with minimum εHf (T) values of −25 are widespread. The unique detrital age spectra for various parts of the craton provide a basis for unravelling the age of buried domains of the Siberian craton. A correlation of isotopic records from different domains, combined with geological evidence, may suggest that the craton consists of (1) the Archean unit, younging toward the present N-W direction and (2) three N-S-trending Paleoproterozoic collisional belts, extending along its western (the Angara belt) and eastern (the Hapschan belt) margins, and in the middle of the craton (the Magan belt). The proposed structural and isotopic domains of the Siberian craton compare well with those of northern Laurentia, providing a new evidence for the two cratons were connected within the Nuna supercontinent.