Meso-Neoproterozoic Grenville-Sveconorwegian intracontinental orogen: history, tectonics, geodynamics

Abstract

Abstract:The objective of this paper is to represent the main features inherent to Grenville-Sveconorwegian Orogen (GSNO) and to propose a model of tectonic and geodynamic evolution of this orogen based on the results of research concerning similar Precambrian tectonic units in the East European Craton. The studies of the conditions and settings related to origin and evolution of GSNO are of special interest, because it is located geographicaly and in a certain sense ideologically in the center of Rodinia, a supposed Neoproterozoic supercontinent. GSNO originated in the MezoNeoproterozoic in the inner region of the Lauroscandia continent. At present, the synformal tectonic structure of GSNO is divided into two portions: Grenville sector along the southeastern margin of the Canadian Shield, and Sveconorwegian sector in the southwestern Scandinavia. The integrity of Lauroscandia was twice disturbed in the MezoNeoproterozoic when oceanic structures resembling the Atlantic Ocean were formed. Later on, the continuity of the continent was restored with the involvement of oceanic lithosphere subduction and accretion and obduction of the island-arc and oceanic terranes. We distinguish two stages in the GSNO history: (1) 'preparatory' stage (from ~1.90 to ~1.16 Ga), and (2) formation of GSNO proper (from ~1.19 to ~0.90 Ga). The manifestations of granulite-facies metamorphism were repeatedly recorded before the Grenville Orogeny at 1.67-1.66, 1.47-1.45, 1.37-1.35, and 1.20-1.18 Ga. The Ottawan stage of the Grenville metamorphism proper is dated between 1.16 and 1.05-1.03 Ga. Metamorphism at the base of Allochthonous Belt corresponds to high-pressure granulite facies and, in a number of places, to hightemperature eclogite facies (800-900 °C at pressure in the range between 14 and 20 kbar). The age of metamorphism of rocks within Paraautochthonous Belt is 1.05-0.95 Ga; metamorphic grade increases from the greenschist facies near the Grenville front to the high-pressure amphibolite facies near Allochthon Boundary Thrust showing an inverted metamorphic zoning. High-pressure granulite-facies metamorphism is characteristic of Sveconorwegian sector; and high-temperature eclogites are observed locally at the base of the allochthonous complexes and within the paraautochthonous complexes. A distinctive feature of GNSO is the abundant occurrence of specific intrusive magmatism. Massifs of anorthosite-mangerite-charnockite-granite (AMCG) and anorthosite-rapakivi granite (ARG) complexes formed 1.8-1.5 Ga ago frame the orogen as a wide arc. In the internal region of GSNO, these complexes were formed successively at 1.16-1.13, 1.09-1.05, 0.99-0.96, and 0.93-0.92 Ga. Later on, after the intrusion, the massifs unevenly underwent granulite-facies metamorphism. The high-temperature magmatism and metamorphism, numerous repeated thermal pulses and enormous crustal body that underwent high-temperature transformation point to a mantle plume as the most adequate source of thermal energy. The model of intracontinental development of GSNO comes

PROVENANCE OF THE PERMIAN-TRIASSIC RED BEDS FROM THE EASTERN PART OF THE MOSCOW BASIN, EAST EUROPEAN PLATFORM: U-Pb LA-ICP-MS AND RAMAN SPECTROSCOPY DETRITAL ZIRCON DATA

“…3. Свеконорвежский [Bingen et al, 2021;Mints, 2017] и Свекофеннский [Daly et al, 2006] выступы кристаллических пород, для которых характерен циркон с возрастом около 1.0 и 1.6-1.8 млрд лет соответственно. Вместе с тем породы, содержащие циркон протерозойского возраста, также известны для комплексов, в настоящее время слагающих фундамент Тимано-Печорского региона и локально обнажающихся в районе Тиманского кряжа [Pystin et al, 2020, и ссылки в данной работе].…”

Deep Crustal Structure and Model of Neorchaean Evolution of the North American Craton

“…14. Реконструкция палеопротерозойской эволюции Лавроскандии (Лавро-Русский внутриконтинентальный овальный коллизионный ороген): (а)~2.5 млрд лет, (б)~1.8 млрд лет (по [Mints, 2017a], с небольшими изменениями).…”

“…Fig. 14. Reconstruction of the Paleoproterozoic evolution of Lauroscandia (Lauro-Russian intracontinental oval collisional orogen) (modified after [Mints, 2017a]). Ages: (а) -~2.5 Ga, (б) -~1.8 Ga.…”

Age and Provenance of the Riphean Rocks of the Chetlas Group of the Middle Timan: U–Th–Pb (LA-ICP-MS) Dating of Detrital Zircons

“…At the same time, considering the presence of numerous rounded and subrounded grains of this age (Fig. 3), which suggests their repeated reworking (Pettijohn, 1975), they could have been sourced from older sedimentary rocks, particularly those exposed within the Sveconorwegian-Grenvillian Orogen in the northern and northwestern (in the present-day coordinates) sectors of Baltica (Bingen et al, 2008;Mints, 2017;Rivers et al, 2012;Spencer et al, 2015;etc. ).…”

“…The zircons with crystallization ages ranging from 1370 to 1170 Ma were supplied from another source, because rock complexes of this age are virtually absent in the structures of the basement of Baltica (Bogdanova et al, 2008;Lahtinen, 2012;etc.). At the same time, igneous and metamorphic events in the interval of 1.0-1.4 Ga are widely manifested within the Sveconorwegian-Grenvillian Orogen (including the terranes amalgamated within it), located in the northwestern (in the present-day coordinates) sector of Baltica (Bingen et al, 2008;Mints, 2017;Rivers et al, 2012;Spencer et al, 2015;etc.). An earlier U-Th-Pb dating of detrital zircons from the Upper Riphean sandstones of the Dzhezhimskaya Formation in the Southern Timan (Kuznetsov et al, 2010) demonstrated the prevalence of Early Proterozoic and Late Archean grains; at the same time, the studied population contained ~7% of grains with ages from 1350 to 1200 Ma.…”