U-Pb (LA-ICP-MS) age of detrital zircons from sandstones of the crater part of the V. Grib kimberlite pipe and KL-01 magmatic object, Arkhangelsk diamondiferous province (north of the East European Platform)

Abstract

Research subject. Detrital zircons from sandstones that contain no admixtures of magmatic material, sampled from the crater parts of the highly diamondiferous V. Grib kimberlite pipe and KL-01 magmatic object. Both objects are located in the north of the East European Platform, within the Arkhangelsk diamondiferous province, at a distance of ≈100 km from each other. Aim. To obtain the first data on the composition of the U-Pb isotope system of detrital zircons from sandstones of magmatic objects of the Arkhangelsk diamondiferous province in order to evaluate the ages of their sources and reveal correlations with known tectono-thermal events in the continental crust of the region. Materials and methods. Using the LA-ICP-MS method, data were obtained on the composition of the U-Pb isotopic system of 52 zircon grains from the sandstones of the V. Grib pipe and 143 zircon grains from the KL-01 sandstones. Results. Sources of various ages from Archean to Neoproterozoic were established for the studied zircons. However, the majority zircons have Mesoproterozoic age, namely 63 and 65% of grains from the V. Grib pipe and KL-01 object, respectively. The sandstones of the V. Grib pipe contain a larger amount of Meso- and Neo-Archean zircons (≈15%) and a smaller amount of Paleoproterozoic grains (≈14%) compared to those from the KL-01 object ≈7 and 20%, respectively. The population of zircons with the U-Pb ages of 900-700 Ma is absent in the two objects. The minimum age of zircons from sandstones of the crater of the V. Grib pipe (557 ± ± 9 Ma) and KL-01 object (609 ± 9 Ma) is consistent with that of formation of the Vendian sandstones in the area of the pipes of the Arkhangelsk diamondiferous province. Conclusions. The obtained U-Pb age for the studied detrital zircons generally correlate with the previously identified stages of tectono-thermal events in the continental crust of the northern territories of the East European Platform, with the exception of the Mesoproterozoic period 1.7-1.4 and 1.3-1.0 Ga ago, which corresponds to the predominant part U-Pb age values of the studied zircons.