The Archean of the Baltic Shield: Geology, Geochronology, and Geodynamic settings

Слабунов, А. И.; Лобач-Жученко, С. Б.; Bibikova, Elena; Balagansky, V. V.; Sorjonen-Ward, Peter; Volodichev, O. I.; Shchipansky, A. A.; Светов, С. А.; Chekulaev, V. P.; Arestova, N. A.; Степанов, В. А.

doi:10.1134/s001685210606001x

Cited by 70 publications

(27 citation statements)

References 24 publications

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“…Komatiitic to basaltic rocks occur as a sequence varying from 1600 to 1800 m in its reconstructed thickness and consisting of high-Mg volcanic lava flows, interbedded tuffs, tuffites, and volcano-sedimentary and sedimentary rocks ( Fig. 3) (Svetov et al 2001;Slabunov et al 2006).…”

Section: Hautavaara Areamentioning

confidence: 99%

Geochemistry of komatiites and basalts in Archean greenstone belts of Russian Karelia with emphasis on platinum-group elements

et al. 2019

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Archean komatiites form an important host rock for Ni-Cu sulfide deposits in the world. In this study, we examined Archean komatiites and komatiitic basalts from four areas in the Vedlozero-Segozero greenstone belt and two areas in the Tikshozero greenstone belt, Russian Karelia, to constrain their Ni-Cu sulfide mineralization potential using chalcophile element geochemistry. The platinum-group element (PGE) concentrations in these Munro-type komatiitic rocks are at a level of other similar Sundersaturated komatiites and komatiitic basalts globally, with Pt and Pd concentrations in the range of 5-20 ppb and Pd/Ir varying from < 10 (komatiites) to > 15 (komatiitic basalts and basalts). Generally, the metals of the iridium-group elements (IPGEs; Ir, Ru, Os) show a compatible behavior, decreasing in abundance with decreasing MgO, whereas the metals of the palladium group (PPGEs; Pt, Pd, Rh) exhibit an incompatible behavior. The poor correlation between Ir and MgO suggests that olivine fractional crystallization is not the main control on the behavior of IPGE. In contrast, Ir, Ru, and Os show positive correlations with Cr, which is consistent with the compatible behavior of IPGEs in chromite or during the co-precipitation of chromite and platinum-group minerals (PGMs). Palladium, Cu, and Au have been variably mobile during alteration and metamorphism whereas Pt appears to have been less mobile. Some samples from the Khizovaara area show low (Pt/Ti) N ratios, low Ni, and high La/Sm and La/Nb, suggesting localized sulfide saturation in response to crustal contamination. However, the potential of the Russian Karelian greenstone belts for Ni-Cu sulfide mineralization is considered relatively low because most samples show neither enrichment nor depletion of chalcophile elements, and the paucity of dynamic lava channel environments, as indicated by the scarcity of olivine-rich adcumulates. In addition, there appears to be a lack of exposed sulfidic sedimentary rocks in the region.

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Section: Hautavaara Areamentioning

confidence: 99%

Geochemistry of komatiites and basalts in Archean greenstone belts of Russian Karelia with emphasis on platinum-group elements

et al. 2019

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“…2a). It its likely that the depth to the basement in Gaal and Gorbatschev, 1987;Korsman et al, 1997;Koistinen et al, 2001;Slabunov et al, 2006); BLRZthe Bothnia-Ladoga rift zone (after Velichkin et al, 2005); (b) of the East European craton; major rifts are based on Nikishin et al (2011); greenstone belts -after LobachZhuchenko (1988); rapakivi granites and related rocks -after Elming et al (2001). Red dotted line -outline of the craton boundaries; blue dotted line -outline of the Ukrainian shield, black box -region of study (shown in (a) and in the following figures).…”

Section: Introductionmentioning

confidence: 96%

Is the Proterozoic Ladoga Rift (SE Baltic Shield) a rift?

Artemieva

Shulgin

2015

Precambrian Research

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“…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).…”

Section: Geological and Geophysical Settingmentioning

confidence: 99%

“…This resulted, e.g., in a west-southwestward thrusting of LGB. The Belomorian terrane especially suffered from large scale reworking and exhumation in the Lapland-Kola orogeny (SLABUNOV et al 2006;HÖ LTTÄ et al 2008). The newly formed Lapland-Savo-Kola orogenic domain was involved in yet another accretion, when the Svecofennian domain docked to its south-southwest margin.…”

Section: Geological and Geophysical Settingmentioning

confidence: 99%

“…In Central Lapland, however, the change from Archean to Paleoproterozoic lithologies is more complex resulting in additional boundaries in NE-SW and N-S directions. It is an area where both Archean and Paleoproterozoic terranes either halt or intertwine with each other and where the lithologies are dominated by rift related volcano-sedimentary sequences (DALY et al 2006;KORJA et al 2006;SLABUNOV et al 2006). The area is also transected by NW-SE-directed strike slip faults (Sirkka Line/Kittilä Shear Zone (KSZ), Meltaus Shear zone (MSZ); GAÁ L et al 1989;PATISON et al 2006;KORJA and HEIKKINEN 2008).…”

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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The Archean of the Baltic Shield: Geology, Geochronology, and Geodynamic settings

Cited by 70 publications

References 24 publications

Geochemistry of komatiites and basalts in Archean greenstone belts of Russian Karelia with emphasis on platinum-group elements

Geochemistry of komatiites and basalts in Archean greenstone belts of Russian Karelia with emphasis on platinum-group elements

Is the Proterozoic Ladoga Rift (SE Baltic Shield) a rift?

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

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