Archean of Greenland and Fennoscandia

Abstract

The North Atlantic craton in southern West Greenland mainly consists of a tectonic collage of Mesoarchean continental crustal terranes, which were amalgamated at c. 2.7 Ga and are currently exposed at mid-crustal amphibolite to granulite facies levels. Tonalitic orthogneisses predominate, intercalated with slightly older tholeiitic to andesitic metavolcanic rocks and associated gabbro-anorthosite intrusive complexes. The North Atlantic craton also contains enclaves of Eoarchean, c. 3.86-3.6 Ga orthogneisses and supracrustal rocks including the Isua greenstone (or supracrustal) belt. This is the oldest known assemblage of rocks deposited at the surface of the Earth, comprising mafic pillow lavas, banded iron formations and metasedimentary schists with local disseminated graphite of possible biogenic origin. Eoarchean rocks have not been found in Kola and Karelia in Fennoscandia where most rocks are 2.9-2.7 Ga tonalitic-trondhjemitic-granodioritic orthogneisses with intercalated coeval greenstone belts and amphibolites. Mesoarchean 3.0-3.2 Ga rocks are found in the eastern and western parts of the Karelian province. Subduction-related rocks like the Iringora supra-subduction type ophiolite and basalt-andesite-dacite-rhyolite series volcanic rocks in many greenstone belts, as well as eclogites are found in the Archean of Fennoscandia. A clear distinction between Greenland and Fennoscandia is the abundance of 2.75-2.65 Ga igneous rocks in Fennoscandia which indicates that these two cratons had a separate evolution during the Neoarchean.

Quartz and orthopyroxene exsolution lamellae in clinopyroxene and the metamorphic P–T path of Belomorian eclogites

“…The Belomorian Province consists mainly of Meso‐ and Neoarchean (2.9–2.7 Ga) TTG gneisses, greenstone complexes of different generations and paragneisses (similar to those in Karelia; Figure b), which were intensely deformed and metamorphosed in high‐ to moderate‐ P regimes in both the Archean and the Palaeoproterozoic. The Belomorian Province is distinct due to the sporadic occurrences of ophiolites (Iringora complex) and eclogites, which have not been found elsewhere in the Fennoscandian Shield (Glebovitsky, ; Hölttä et al., ; Slabunov, Azimov, Glebovitsky, Zhang, & Kevlich, ; Volodichev, ).…”

Age and P–T conditions of the Gridino‐type eclogite in the Belomorian Province, Russia

“…This orogeny was formed by the collision of Paleoproterozoic juvenile crust in the orogenic core with the surrounding Belomorian and Kola Provinces mainly at 1.93–1.91 Ga (Daly et al., ). The most abundant lithological components of the Belomorian Province are the 2.9–2.7 Ga tonalite–trondhjemite–granodiorite (TTG) gneisses that were reworked in the Paleoproterozoic (Hölttäs et al., ). The Gridino‐ and Salma‐type eclogites occur as lenticular bodies within the TTG gneisses.…”

“…No evidence of Archean events has been identified within the Paleoproterozoic Lapland–Kola collisional orogeny. The highest grade of Archean metamorphism evident in the Belomorian Province is the high‐ P amphibolite to granulite facies metamorphism recorded by kyanite‐bearing gneisses and granulite–enderbite–charnockite complexes (Bibikova, Bogdanova, Glebovitskii, Claesson, & Skiöld, ; Hölttäs et al., ). The highest grade granulite facies metamorphism occurs in the northwestern Kola Province (Hölttäs et al., ), whereas most of the Karelian Province records upper amphibolite facies to granulite facies conditions except for some greenstone belts with lower or middle amphibolite facies conditions (Hölttäs et al., ; Slabunov et al., ).…”

“…Modified after Hölttäs et al. (). (c) Geological map of the Stolbikha Island and sample locations (modified after Li, Zhang, Wei, & Slabunov )…”

New data on detrital zircons from the sandstones of the lower Cambrian Brusov Formation (White Sea region, East-European Craton): unravelling the timing of the onset of the Arctida–Baltica collision

“…Yet, it was mostly filled by erosional products from Palaeoproterozoic collisional orogens and/or from reworked sedimentary sequences containing products of the initial destruction of those Palaeoproterozoic orogens. Those Palaeoproterozoic orogens sutured Archaean protocratons into the supercontinent Columbia and their relicts compose now the basement of the EEC (Piper 2000(Piper , 2007Rogers and Santosh 2002;Zhao et al 2002Zhao et al , 2011Lahtinen et al 2005;Daly et al 2006;Сlaesson et al 2006;Korja et al 2006;Hölttä et al 2008;Bogdanova et al 2008;Bingen et al 2008b;Meert 2012) (Figure 1). This is consistent with previous reports on the amount of early Palaeoproterozoic juvenile zircons found in Palaeoproterozoic sedimentary units of northeastern Fennoscandia (i.e.…”