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Abstract

For the last two decades, the end of the voluminous phase of eruptions of the Siberian Traps large igneous province has been constrained by a U-Pb date of discordant baddeleyite collected from the Guli carbonatite intrusion with the assumption that the discordance resulted from unsupported Pb-207. In this study we have re-analysed baddeleyite from the same intrusion and found two types of discordance: (1) due to (207) Pb-excess, and (2) radiogenic lead loss from high U mineral inclusions. The former implies that baddeleyite is an efficient scavenger of protactinium during crystallisation, leaving the magma depleted in this element. Together with a published high precision U-Pb date of 252.24 +/- 0.08 Ma for the Arydzharisky Formation, our new date of 250.33 +/- 0.38 Ma for the Guli carbonatite constrains the total duration of the voluminous eruptions of the Siberian Traps LIP at 1.91 +/- 0.38 million years. The lower intercept of the (Pa-231)/(U-235) corrected discordance line yields a date of 129.2 +/- 65.0 Ma, which points to the widespread Early Cretaceous rifting in East and Central Asia.

Item Type:	Article
Authors/Creators:	Ivanov, AV and Corfu, F and Kamenetsky, VS and Marfin, AE and Vladykin, NV
Journal or Publication Title:	Geochemical Perspectives Letters
Publisher:	European Association of Geochemistry
ISSN:	2410-339X
DOI / ID Number:	https://doi.org/10.7185/geochemlet.2117
Copyright Information:	Copyright 2021 The AuthorsLicensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)https://creativecommons.org/licenses/by-nc-nd/4.0/
Related URLs:	Google Scholar: Kamenetsky, VS UTAS Profile: Kamenetsky, VS
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