Unserpentinized Harzburgites of the Voikar–Synya Massif in the Polar Urals as the Initial Chromium Source for the Deposit Formation
摘要
Abstract
Composition and age of unserpentinized harzburgites found as boudins and relict bodies in the Voikar–Synya massif in the olivine–antigorite fields have been studied. Rock and mineral structure and composition, as well as REE distribution and Sm–Nd absolute dating (≈2330 Ma) make it possible to consider these unserpentinized harzburgites as mantle fragments and the earliest ultramafic rocks of the Voikar–Synya massif. Silicates of these harzburgites are characterized by higher chromium which turns into chrome spinellide in different subsequent processes. Based on the data obtained, the resources of chromium mobilized during the transformation of primary ultramafic rocks have been evaluated.