INTEGRATED PROVENANCE ANALYSIS OF UPPER PALEOZOIC – MESOZOIC DEPOSITS OF THE NORTHERN SIBERIA: U–PB AGES, WHOLE-ROCK CHEMISTRY AND SANDSTONE PETROGRAPHY

The study area is located in the northern Siberia occupying area between the Kheta and Lena rivers. Carboniferous deposits contain Precambrian zircons of 2500-2600, 2000-1800, 600-650, 700-750 and 800-850 Ma. Paleozoic grains have a set of peaks at 500-520, 470-485, 390-400, 330-345 Ma. Permian samples contain predominantly ca. 290 Ma and 320-330 Ma and 480-490 Ma zircons. Immature composition with high content of lithic fragments reveals short transportation of clastic material. Both sandstone petrography and chemical composition shows wide distribution of mafic magmatic rocks in the provenance of Triassic rocks. U-Pb ages of detrital zircons in Triassic sandstones are similar to those in Permian sandstones.

Detrital zircon age distribution in Jurassic sandstones varies throughout the study area. In the west, all samples have a set of peaks from ca. 250 Ma to ca. 510 Ma with only a few Paleoproterozoic and Archean grains. In the east, detrital zircon ages also vary greatly, but ca. 270-290 Ma grains predominate.

Detrital zircon age distribution shows significant increasing of Paleoproterozoic and Archean rocks in provenance of Cretaceous samples pointing to predominant Siberian Craton basement erosion.

Most likely provenance of Archean and Paleoproterozoic zircons is Siberian Craton basement or cratonic sandstones with high concentration of those grains. Neoproterozoic and Paleozoic magmatic rocks are widespread in the thrust and fold belts (FTB) surrounding Siberian Craton. Detrital zircon age distributions as well as data on composition of the eroded rocks and transportation history show that the best candidates for provenance are Taimyr FTB and Central Asian FTB with some input from the basement of the West Siberia sedimentary basin.

This research was supported by TGS-Nopec Company, RFBR grants 12-05-33018, 13-05-00700, 13-05-00943, research grant of Saint Petersburg State University and Grant of President of Russia for Young Scientist MK-2902.2013.5.