Trace Element Composition of Archean Detrital Zircons from Jatulian Terrigenous Rocks of Fennoscandia

Detrital zircons with an age of 3.65–3.87 Ga have been found earlier in Jatulian terrigenous rocks from the eastern Fennoscandian Shield, i.e., the Karelian and Kola regions (Kozhevnikov et al., 2010; Smol’kin et al., 2011, 2019), while rocks of this age are not reported in the inferior Sumian–Sariolian complexes and in the Archean basement. To establish the provenance area and composition of the sources, the first study of geochemical composition (rare-earth and trace elements) of detrital zircons from Jatulian red gravelstones of the Luchlompol’skaya Fm., Pechenga structure, quartzites of the Volomskaya syncline, and cement of conglomerates in the western Onega Trough, which are located at considerable distances from each other, has been carried out. The age of detrital zircon grains ranges mainly within 2.70–3.23 Ga. Some of the detrital zircon grains are of igneous type. Grains and outer envelopes of zonal grains having the youngest age (2.70–2.72 Ga) are referred to the metamorphic type. “Porous” zircon that underwent a fluid effect is also present. The main sources of igneous zircon grains were tonalite and trondhjemite gneisses and acid granulites, which are widespread in the vicinities of the studied structures and were revealed in the lower part of the Kola Superdeep Well (VSD-3), as well as gneisses and amphibolites of the Vodlozero block. The source of detrital zircon grains with an age of 3.65–3.87 Ga is the Siurua trondhjemite gneiss (northern Finland). Their erosion and transportation of zircons took place 2.2–2.1 Ga ago along the western margin of the Svecofennian–Pre-Labradorian Ocean that existed at the initial stage of the Columbia Supercontinent assemblage.