Abstract
Subject. The ideas of plume tectonics became active and developing only several years later than the theory of plate tectonics. But in the Urals, the question of plume tectonics, contrary to plate tectonics, was not raised, with rare exceptions, until the latest decade. It is explained by great difficulties in revelation of plumes in any ancient foldbelt, because seismic tomography is not applicable, and magmatic complexes are partly covered by younger sediments, partly eroded, and, additionally, undergone distortion, connected with continental break-ups and drift, subduction and fold-and thrust deformations. Materials and methods. However in recent years, among the magmatic complexes of the Urals (mostly in its western areas), Pay-Khoy and Novaya Zemlya, thanks to precise definition of magmatic formations ages, study of their geodynamically conditioned petrochemistry and their correlation with other regions, the author identified ten levels of probable manifestations of plume/superplume events. Results. It is assumed that in the modern Urals the relics of the following plumes: Navysh (Lower Riphean), Mashak (Middle Riphean), Arsha and Kiryabinka (Terminal Riphean), Mankhambo (Cambrian), Kidryas (Lower-Middle Ordovician, Ushat (Late Ordovician-Lower Silurian), Kola-Dniepr (Devonian), Stepninsk (Permian), Ural-Siberian (Lower-Middle Triassic) had remained.
Highlights
In the Urals, the question of plume tectonics, contrary to plate tectonics, was not raised, with rare exceptions, until the latest decade. It is explained by great difficulties in revelation of plumes in any ancient foldbelt, because seismic tomography is not applicable, and magmatic complexes are partly covered by younger sediments, partly eroded, and, undergone distortion, connected with continental break-ups and drift, subduction and fold-and thrust deformations
Puchkov V.N., Ernst R.E., Hamilton M.A., Söderlund U., Sergeeva N
Summary
К аршинию может быть отнесена также более молодая Кирябинская расслоенная перидотитпироксенит-габбровая интрузия, расположенная на северо-востоке Башкирского мегантиклинория возрастом 680 ± 3.4 млн лет [Краснобаев и др., 2013в] (cм. рис. 1). 5. Кембрийские А-граниты Приполярного и Полярного Урала (Маньхамбовский комплекс). Абсолютные возрасты по цирконам методом термоионной эмиссии свинца, U-Pb методом, а также по данным SHRIMP имеют разброс от терминального рифея до кембрия (от 695 ± 19 до 515 ± 8 млн лет, с подавляющим преобладанием вендских цифр). Образование грабеновых фаций – грубообломочных толщ весьма переменной мощности, сопровождаемое субщелочным вулканизмом, связано на Урале с рифтогенезом, который предваряет заложение пассивной континентальной окраины и океанического бассейна [Puchkov, 2002; Пучков, 2010] Цифры на схеме: 1–10 – ранне-среднеордовикские рифтовые вулканиты и дайки, отвечающие условиям пассивной вулканической окраины Это позволяет предполагать образование в раннем ордовике единой КМП и воздействие единого суперплюма на раскалывающийся континент или на сближенные континенты
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