Results 11 to 20 of about 322 (183)

The Salittu Formation in southwestern Finland, part II: Picritic-basaltic volcanism in mature arc environment [PDF]

open access: yesBulletin of the Geological Society of Finland, 2017
Svecofennian orogen that contain ultramafic rocks. New samples were collected from the picritic and basaltic rocks as well as spatially associated gabbroic rocks, and their major and trace element compositions are presented and discussed here.
M. Nironen
doaj   +1 more source

Stratigraphy of the Pitangui Synclinorium, northwest of the Quadrilátero Ferrífero mineral province - Brazil: magmatism and sedimentation from Archean to Neoproterozoic

open access: yesJournal of the Geological Survey of Brazil, 2023
The Pitangui Synclinorium is located in the northwestern portion of the Quadrilátero Ferrífero mineral province, São Francisco Craton, in southeast Brazil.
Marcelo de Souza Marinho   +8 more
doaj   +1 more source

Radiometric ages and other isotopic data bearing on the evolution of Archaean crust and ores in the Kuhmo-Suomussalmi area, eastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1999
The Archaean greenstone-gneiss terrain in the Kuhmo-Suomussalmi district in eastern Finland has been isotopically studied in connection with regional bedrock mapping and local mineral exploration projects.
M. Vaasjoki, K. Taipale, I. Tuokko
doaj   +1 more source

Geology of giant quartz veins and their host rocks from the Eastern Pyrenees (Southwest Europe)

open access: yesJournal of Maps, 2023
Giant Quartz Veins (GQVs) are ubiquitous in different tectonic settings and, besides being often related to hydrothermal ore deposits, also represent large-scale fingerprints of the structural and geochemical history of the rocks in which they are hosted.
Eloi González-Esvertit   +5 more
doaj   +1 more source

The Pyhäntaka formation, Southern Finland: A sequence of metasandstones and metavolcanic rocks upon an intra-orogenic unconformity [PDF]

open access: yesBulletin of the Geological Society of Finland, 2011
Detrital zircon studies suggest that the few quartzite occurrences in southern Finland are younger than 1.87 Ga and express sedimentation after 1.89–1.87 Ga accretional deformation and metamorphism in the Svecofennian orogenic belt.
M. Nironen
doaj   +1 more source

Stratigraphy of the central parts of the Palaeoproterozoic Tampere Schist Belt, southern Finland: review and revision [PDF]

open access: yesBulletin of the Geological Society of Finland, 1998
The arc-type Palaeoproterozoic volcanic-sedimentary Tampere Schist Belt (TSB), close to the centre of the Svecofennian Orogen, comprises an E-W-striking major synform in its central parts.
Y. Kähkönen
doaj   +1 more source

Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting

open access: yesBrazilian Journal of Geology, 2020
Field, petrological and LA-ICP-MS U-Pb geochronological data of metavolcanic rocks were used to interpret the petrological processes and to propose the tectonic setting for the Mundo Novo greenstone belt (MNGB) in the eastern São Francisco Craton.
Ricardo Ramos Spreafico   +3 more
doaj   +1 more source

THE NEOPROTEROZOIC ISLAND-ARC ASSOCIATION OF THE MUKODEK GOLD-ORE FIELD, NORTHERN BAIKAL AREA

open access: yesГеодинамика и тектонофизика, 2015
Metamorphosed volcanic rocks of the Ushmukan suite were studied in the Mukodek gold-ore field located in the Baikal-Muya belt in the Northern Baikal area, Russia. The Ushmukan suite shows interleaving of ortoschists which compositions are widely variable.
V. A. Vanin   +2 more
doaj   +1 more source

The Encantada Granite: registration of a peraluminous intrusion in the Rondonian Province - San Ignacio, in SW Amazonic Craton, Mato Grosso, Brazil [PDF]

open access: yesGeologia USP. Série Científica, 2015
The Encantada Granite occurs on the extreme southwest of the state of Mato Grosso, SW of the Amazonian Craton, near the border of Brasil/Bolívia. It corresponds to an body oriented to NNW direction that intruded metasedimentary and metavolcanic rocks ...
Brena Verginassi do Nascimento   +2 more
doaj   +1 more source

U-Pb dating, Lu-Hf isotope systematics and chemistry of zircon from the Morro do Polvilho meta-trachydacite: constraints on sources of magmatism and on the depositional age of the São Roque Group

open access: yesGeologia USP. Série Científica, 2018
We present new in situ geochronological data of controversial silicic metavolcanic rocks from the lower terrigenous-metavolcanic sequence of the São Roque Group, Ribeira Belt, confirming that they are older than the rocks of higher-metamorphic grade ...
Renato Henrique-Pinto   +2 more
doaj   +1 more source

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