Evidence of permafrost in the Paleoproterozoic (c. 1.9 Ga) of Central Sweden
Permafrost and Periglacial Processes, Volume 32, Issue 1, Page 169-177, January/March 2021., 2021 Abstract This paper reports on an ice‐wedge pseudomorph that formed and is preserved in metavolcanic host material that was later transformed to metamorphic solid bedrock. It has been dated to 1,895 ± 5 Ma by U–Pb geochronology of zircon in the bedrock, an Early Proterozoic age.
Jef Vandenberghe +4 more
wiley +1 more source
1.88 Ga granitoids at Sorsakoski, Central Finland: A-type magmatism within the Raahe-Ladoga suture zone [PDF]
Bulletin of the Geological Society of FinlandFour quartz monzonite – granite intrusions forming the Sorsakoski granite lithodeme, are found within the Raahe-Ladoga suture zone in Central Finland. The prevailing potassium feldspar megacrystic quartz monzonites and granites form a bimodal association
Perttu Mikkola +3 more
doaj +1 more source
Transactions of the Karelian Research Centre of the Russian Academy of Sciences, 2018 A 3D model of the deep structure of the Late Paleoproterozoic Svecofennian accretionary orogen is presented. The model is based on coordinated data of geological mapping, seismic reflection surveys along the profiles FIRE-2-2a-1 and FIRE-3-3a ...
Михаил Вениаминович Минц +5 more
doaj +1 more source
Mafic-ultramafic intrusions of Matokulma, Palojärvi, and Hongonniittu within the Central Finland Granitoid Complex with special reference to their petrogenesis and ore potential [PDF]
Bulletin of the Geological Society of FinlandWe describe three previously unknown or poorly studied mafic-ultramafic intrusions (Matokulma, Palojärvi, Hongonniittu) from the south-central part of the Paleoproterozoic Central Finland Granitoid Complex (CFGC).
Seppo Karvinen +5 more
doaj +1 more source
Paleoproterozoic post-orogenic magmatism in southern Finland; geochemical, geochronological and Sr-Nd isotopic constraints on origin and magmatic evolution [PDF]
Bulletin of the Geological Society of FinlandFifteen post-orogenic, basic to acidic High-Barium-Strontium (HiBaSr) intrusions of shoshonitic affinity have been recognized in central and southern Finland.
Oliver Teräs +5 more
doaj +1 more source
Magnetite and ilmenite from some Finnish rocks [PDF]
Bulletin of the Geological Society of Finland, 1972 Coexisting accessory magnetite and ilmenite -were separated and chemically analysed from five Finnish Precambrian rocks: anorogenic olivine diabase and gabbroanorthosite as well as three metamorphosed Svecofennian quartz diorites.
I. Haapala, P. Ojanperä
doaj +1 more source
Seismic structure of the central Svecofennian lithosphere
, 2021 Lithospheric structures in the Fennoscandian Shield in Sweden have been studied by a number of large-scale wide-angle seismic reflection/refraction (WARR) and normal-incidence reflection profiles since the 1960s. Among these were the over 2000 km long Fennoscandian Long Range (FENNOLORA) project in 1979 and the Baltic and Bothnian Echoes from the ...
openaire +2 more sources
The 1.88 Ga Kotalahti and Vammala nickel belts, Finland: Geochemistry of the mafic and ultramafic metavolcanic rocks [PDF]
Bulletin of the Geological Society of Finland, 2009 The mafic and ultramafic volcanic rocks within the Svecofennian (1.88 Ga) Kotalahti and Vammala Nickel Belts, Finland, are spatially associated and coeval with a suite of mineralized mafic-ultramafic intrusions.
S.J. Barnes +4 more
doaj +1 more source
Early Proterozoic stratigraphy of the Salahmi-Pyhäntä area, central Finland, with an emphasis on applying the principles of lithodemic stratigraphy to a complexly deformed and metamorphosed bedrock [PDF]
Bulletin of the Geological Society of Finland, 1988 The medium-highly metamorphozed and intensely deformed early Proterozoic supracrustal rocks of the study area, located at the boundary zone between the Karelian and Svecofennian zones in central Finland, are classified following the recommendations of ...
K. Laajoki, J. Luukas
doaj +1 more source
Structural observations and U-Pb mineral ages from igneous rocks at the Archaean-Palaeoproterozoic boundary in the Salahmi Schist Belt, central Finland: constraints on tectonic evolution [PDF]
Bulletin of the Geological Society of Finland, 1999 The study area in Vieremä, central Finland, contains part of Archaean-Palaeoproterozoic boundary. In the east, the area comprises Archaean gneiss and the Salahmi Schist Belt. The rocks of the schist belt are turbiditic metagreywackes, with well-preserved
K. Pietikäinen, M. Vaasjoki
doaj +1 more source