UPb geochronology of layered mafic intrusions in the eastern Baltic Shield: implications for the timing and duration of Paleoproterozoic continental rifting

Amelin, Y.; Heaman, Larry M.; Семенов, В. С.

doi:10.1016/0301-9268(95)00015-w

Cited by 285 publications

(134 citation statements)

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“…2,426 Ma, the approximate age of the Makganyene Formation glaciation and near-coeval Ongeluk Formation volcanic rocks in the Transvaal Supergroup. In addition, the 2,442 ± 2 Ma Seidorechka Formation and the overlying 2,435 ± 2 Ma Polisarka formations (34,35) overlying the Kola-Karelia Craton may tightly bracket the oldest Paleoproterozoic glacial event between ca. 2,442 Ma and 2,435 Ma, respectively, implying that it lasted less than 7 My (Fig.…”

Section: Discussionmentioning

confidence: 99%

Timing and tempo of the Great Oxidation Event

Gumsley

Chamberlain

Bleeker

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

408

274

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The first significant buildup in atmospheric oxygen, the Great Oxidation Event (GOE), began in the early Paleoproterozoic in association with global glaciations and continued until the end of the Lomagundi carbon isotope excursion ca. 2,060 Ma. The exact timing of and relationships among these events are debated because of poor age constraints and contradictory stratigraphic correlations. Here, we show that the first Paleoproterozoic global glaciation and the onset of the GOE occurred between ca. 2,460 and 2,426 Ma, ∼100 My earlier than previously estimated, based on an age of 2,426 ± 3 Ma for Ongeluk Formation magmatism from the Kaapvaal Craton of southern Africa. This age helps define a key paleomagnetic pole that positions the Kaapvaal Craton at equatorial latitudes of 11°± 6°at this time. Furthermore, the rise of atmospheric oxygen was not monotonic, but was instead characterized by oscillations, which together with climatic instabilities may have continued over the next ∼200 My until ≤2,250-2,240 Ma. Ongeluk Formation volcanism at ca. 2,426 Ma was part of a large igneous province (LIP) and represents a waning stage in the emplacement of several temporally discrete LIPs across a large low-latitude continental landmass. These LIPs played critical, albeit complex, roles in the rise of oxygen and in both initiating and terminating global glaciations. This series of events invites comparison with the Neoproterozoic oxygen increase and Sturtian Snowball Earth glaciation, which accompanied emplacement of LIPs across supercontinent Rodinia, also positioned at low latitude.Great Oxidation Event | Snowball Earth | Paleoproterozoic |

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Section: Discussionmentioning

confidence: 99%

Timing and tempo of the Great Oxidation Event

Gumsley

Chamberlain

Bleeker

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

408

274

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“…The lower limit of the North Pechenga Group is defined by the emplacement age of the Mt. General'skaya intrusion (2505 ± 1.6 Ma U-Pb on baddeleyite: Amelin et al 1995). The upper age limit is defined by ultramafic flows and intrusions of Pilgujärvi Formation (1977 ± 52 Ma, SmNd and Pb/Pb on mineral separates : Hanski 1992).…”

Section: Geological Settingmentioning

confidence: 99%

The Composition and Mode of Formation of the Pechenga Nickel Deposits, Kola Peninsula, Northwestern Russia

Barnes

Melezhik

Sokolov³

2001

The Canadian Mineralogist

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The Pechenga Ni-sulfide deposits, in the Kola Peninsula of Russia, are associated with ferropicrite flows and intrusions. The sulfides are divided into five types: 1) disseminated sulfides within the olivine cumulate portions of the ferropicrites, 2) massive sulfides, which occur at the contact between the ferropicrites and the country-rock black schists, 3) breccia-matrix sulfides, which occur at the contact between the ferropicrites and the schists, and in some cases continue for hundreds of meters subparallel to the contact but within the footwall, 4) chalcopyrite vein or stringer sulfides, which occur in the footwall, and 5) pyrite-rich layers, concretions and lenses in the sedimentary rocks. The disseminated sulfides have similarly shaped mantle-normalized patterns of chalcophile metal abundances to those of the ferropicrites, and could have formed in equilibrium with the ferropicritic magma at moderate R factors (250). The rocks are depleted in platinum-group elements (PGE), suggesting that the magma reached sulfide saturation prior to the formation of the ores. Sulfur isotope data indicate that the S was derived from the sediments onto and into which the ferropicrites were emplaced. The high As and Sb concentrations in the sulfides may have been derived from the sediments. The massive sulfides show a wider variety of composition than the disseminated sulfides; some sulfides are enriched in Os, Ir, Ru, Rh and depleted Pt, Pd, Ag, Au, Cu, Sb, As, Se. This pattern is attributed to the accumulation of monosulfide solidsolution during crystallization of a sulfide liquid. The sedimentary sulfides are richer in As and Sb than the disseminated and massive sulfides, but poorer in all the other chalcophile elements. The breccia-matrix sulfides consist of sedimentary and ultramafic fragments in a sulfide matrix. Compared with vein sulfides from other deposits, those from Pechenga have a very unusual composition. They are not only rich in Cu and Ag, but also in Os, Ir, Ru and Rh, and they are depleted in Pt, Pd, Au, As, Sb and Se.Keywords: nickel sulfide deposits, platinum-group elements, arsenic, antimony, gold, selenium, silver, rare-earth elements, ferropicrites, sulfur isotopes, Pechenga, Russia. SOMMAIRELes gisements de nickel de Pechenga, dans la péninsule de Kola, en Russie, sont associés à des coulées et des massifs intrusifs de ferropicrite. Les sulfures de nickel se présentent en cinq associations: 1) sulfures disséminés dans les parties cumulatives des ferropicrites, 2) sulfures massifs au contact entre les ferropicrites et les schistes noirs encaissants, 3) sulfures formant la matrice de brèches de ferropicrite et de schiste, dans certains cas se prolongeant des centaines de mètres le long du contact mais invariablement situés au dessus de la paroi inférieure, 4) veines de chalcopyrite ou sulfures en veinules, dans la paroi inférieure, et 5) accumulations de pyrite formant concrétions et lentilles dans l'encaissant sédimentaire. Les sulfures disséminés possèdent des tracés de concentrations en mét...

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“…Several authors (AMELIN et al 1995;HEAMAN 1997;HANSKI and HUHMA 2005;MELEZHIK 2006;LAHTINEN et al 2008) have suggested that the layered intrusions were triggered by the arrival of a plume head beneath Lapland. We suggest that the arrival of the plume not only initiated a continental spreading centre or triple junction ( Fig.…”

Section: Discussionmentioning

confidence: 99%

“…The Shield comprises Archean and Paleoproterozoic terranes that were merged during the Svecofennian and Lapland-Kola orogenies at 1.9 Ga ago (GORBATSCHEV and BOGDANOVA 1993;DALY et al 2006;KORJA et al 2006 The Archean terranes (WKC, CKC, BP) formed between 3.7 and 2.7 Ga and were welded together in Neoarchean collisions at 2.9 Ga (SLABUNOV et al 2006). As a response to a mantle plume, the Neoarchean orogenic domain rifted at the beginning of the Paleoproterozoic Era (AMELIN et al 1995;HEAMAN 1997;SORJONEN-WARD et al 1997;HANSKI and HUHMA 2005;MELEZHIK 2006;LAHTINEN et al 2008). Several rift basins and/or rifted margins [e.g., CLGB, KuB, Peräpohja belt (PB), Lapland granulite belt (LGB)] developed in the west, northwest and north.…”

Section: Geological and Geophysical Settingmentioning

confidence: 99%

“…1; AMELIN et al 1995;HEAMAN 1997;SORJONEN-WARD et al 1997;ERNST and BUCHAN 2001;HANSKI and HUHMA 2005;MELEZHIK 2006). The northern part of the Shield is a collage of Archean and Paleoproterozoic terranes that were accreted in the Svecofennian and Lapland-Kola orogenies approximately 1.9-1.8 Ga ago (GORBATSCHEV and BOGDANOVA 1993;DALY et al 2006;KORJA et al 2006).…”

Section: Introductionmentioning

confidence: 99%

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Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile

Tiira

Janik

Kozlovskaya

et al. 2013

Pure Appl. Geophys.

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Abstract-We have studied the lateral velocity variations along a partly buried inverted paleo-rift in Central Lapland, Northern Europe with a 2D wide-angle reflection and refraction experiment, HUKKA 2007. The experiment was designed to use seven chemical explosions from commercial and military sites as sources of seismic energy. The shots were recorded by 102 stations with an average spacing of 3.45 km. Two-dimensional crustal models of variations in P-wave velocity and Vp/Vs-ratio were calculated using the ray tracing forward modeling technique. The HUKKA 2007 experiment comprises a 455 km long profile that runs NNW-SSE parallel to the Kittilä Shear Zone, a major deformation zone hosting gold deposits in the area. The profile crosses Paleoproterozoic and reactivated Archean terranes of Central Lapland. The velocity model shows a significant difference in crustal velocity structure between the northern (distances 0-120 km) and southern parts of the profile. The difference in P-wave velocities and Vp/Vs ratio can be followed through the whole crust down to the Moho boundary indicating major tectonic boundaries. Upper crustal velocities seem to vary with the terranes/compositional differences mapped at the surface. The lower layer of the upper crust displays velocities of 6.0-6.1 km/s. Both Paleoproterozoic and Archean terranes are associated with high velocity bodies (6.30-6.35 km/s) at 100 and 200-350 km distances. The Central Lapland greenstone belt and Central Lapland Granitoid complex are associated with a 4 km-thick zone of unusually low velocities (\6.0 km/s) at distances between 120 and 220 km. We interpret the HUKKA 2007 profile to image an old, partly buried, inverted continental rift zone that has been closed and modified by younger tectonic events. It has structural features typical of rifts: inward dipping rift shoulders, undulating thickness of the middle crust, high velocity lower crust and a rather uniform crustal thickness of 48 km.

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UPb geochronology of layered mafic intrusions in the eastern Baltic Shield: implications for the timing and duration of Paleoproterozoic continental rifting

Cited by 285 publications

References 39 publications

Timing and tempo of the Great Oxidation Event

Timing and tempo of the Great Oxidation Event

The Composition and Mode of Formation of the Pechenga Nickel Deposits, Kola Peninsula, Northwestern Russia

Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile

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