Early Archean crust of the Middle Dnepr and Azov domains, Ukrainian Shield--evidence from ages of detrital zircons in Mesoarchean greenstone belts

2010 ◽  
Vol 310 (10) ◽  
pp. 1595-1622 ◽  
Author(s):  
E. Bibikova ◽  
S. Claesson ◽  
A. Fedotova ◽  
G. Artemenko ◽  
L. Ilyinsky
Keyword(s):  
Detrital Zircons ◽  
Ukrainian Shield ◽  
Archean Crust ◽  
Greenstone Belts

scholarly journals THE PALEOARCHEAN (3.3 Ga) AND MESOARCHEAN (3.0 Ga) TTGs OF THE WESTERN AZOV AREA, THE UKRAINIAN SHIELD

2021 ◽  
pp. 35-47
Author(s):  
G.V. Artemenko ◽  
L.V. Shumlyanskyy
Keyword(s):  
Chemical Composition ◽  
Detrital Zircons ◽  
Geochemical Characteristics ◽  
Ukrainian Shield ◽  
Metamorphic Rocks ◽  
The West ◽  
Siliceous Rocks ◽  
Zircon Crystallization ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

A large anticline structure that includes the West Azov and Remivka blocks occurs in the western part of the Azov Domain of the Ukrainian Shield. These blocks are composed of rocks of the Mesoarchean (3.2-3.0 Ga) granite-greenstone association and relics of an older basement. The anticline is divided into two parts by the Bilotserkivka structure of sub-latitudinal strike; the northern part includes the Huliaipole and Remivka blocks, and the southern part is comprised of the Saltycha anticline. The Archean plagiogranitoids of the West Azov underwent intense dislocation metamorphism during the Paleoproterozoic. In many areas they were transformed into plagioclase gneisses that were attributed to the Paleoarchean “Kainkulak thickness” of the Azov Series. Detailed geological-structural and geochronological studies are required to define the age of these gneisses.We have chosen two areas for our studies: the Lantsevo anticline within the Bilotserkivka structure, and the Ivanivka area in the eastern part of the Saltycha anticline. The Bilotserkivka structure is composed of rocks of the Central Azov Series and highly deformed Archean formations. We have dated plagiogneisses of the Lantsevo anticline. These rocks contain large relics of metamorphic rocks of unknown age, including two-pyroxene and pyroxene crystalline schists, and pyroxenemagnetite quartzites (BIF). In terms of chemical composition, two-pyroxene crystalline schists correspond to tholeiitic basalts and basaltic komatiites. Ferruginous-siliceous rocks belong to the Algoma type typical for the Archean greenstone belts. Biotite gneisses are similar to the medium-pressure tonalite-trondhjemite-granodiorite rocks (TTGs). The U-Pb age of zircon crystallization from biotite gneisses is 3299 ± 11 Ma. At 30 km in the western part of the Bilotserkivka structure, we have previously identified quartz diorites having an age of 3297 ± 22 Ma. In terms of geochemical characteristics, they correspond to low-pressure TTGs. These data show that the Bilotserkivka structure is a block representing an ancient basement. In the Ivanivka area in the eastern part of the Saltycha anticline, the strike of the Archean rocks was reorientated from northwestern to latitudinal. The studied dislocated trondhjemites of the Ivanivka area correspond to TTGs in terms of the geochemical characteristics. They contain numerous relics of highly altered amphibolites. The U-Pb age of zircon crystallization from trondhjemite is 3013 ± 15 Ma. These rocks are of the same age as TTGs of the Shevchenko Complex cutting through the sedimentary-volcanogenic rocks of the greenstone structures of the Azov Domain. They share age and geochemical characteristics with biotite and amphibole-biotite gneisses of the “Kainkulak thickness” in Zrazkove village located at the Mokra Konka river (3.1-3.0 Ga) and with biotite gneisses in the lower reaches of the Kainkulak river (2.92 Ga). Thus, gneisses of the “Kainkulak thickness” in fact represent the Mesoarchean TTGs of the Shevchenko Complex, which were transformed in the Paleoproterozoic time due to the dislocation metamorphism. Late Paleoarchean (3.3 Ga) tonalites are known in the West Azov and the KMA domains; they probably also occur in the basement of the Middle Dnieper domains, where detrital zircons of this age have been reported. These data allow us to conclude the existence of a large Late Paleoarchean (3.3 Ga) protocraton, in which the Mesoarchean (3.2-3.0 Ga) greenstone belts and TTGs of the eastern part of the Ukrainian Shield and the KMA Domain were formed.

scholarly journals The Paleoarchean and Mesoarchean TTGs of the western Azov area, the Ukrainian Shield

2021 ◽  
pp. 61-74
Author(s):  
G.V. Artemenko ◽  
L.V. Shumlyanskyy
Keyword(s):  
Detrital Zircons ◽  
Geochemical Characteristics ◽  
Ukrainian Shield ◽  
The West ◽  
Greenstone Belts

A large anticline structure occurs in the western part of the Azov Domain of the Ukrainian Shield. It is composed of rocks of the Mesoarchean (3.2-3.0 Ga) granite-greenstone association and relics of an older basement. The anticline is divided into two parts by the Bilotserkivka structure of sub-latitudinal strike. The northern part includes the Huliaipole and Remivka blocks, and the southern part comprises the Saltycha anticline. The U-Pb age of plagiogneisses of the Lantsevo anticline of the Bilotserkivka structure is 3299 ± 11 Ma. In terms of geochemical characteristics, they correspond to TTGs. In the western part of the Bilotserkivka structure, we previously identified quartz diorites having an age of 3297 ± 22 Ma. These data show that the Bilotserkivka structure represents an ancient basement. Dislocated trondhjemites were studied in the Ivanivka area at the eastern part of the Saltycha anticline. They contain numerous relics of heavily altered amphibolites. The U-Pb age of zircons from trondhjemite is 3013 ± 15 Ma. These rocks are of the same age as TTGs of the Shevchenko Complex cutting through the sedimentary- volcanogenic rocks of the greenstone structures of the Azov Domain. They share age and geochemical characteristics with biotite and amphibole-biotite gneisses of the “Kainkulak beds” in the Zrazkove village located at the Mokra Konka river (3.1-3.0 Ga) and with biotite gneisses in the lower reaches of the Kainkulak river (2.92 Ga). Thus, gneisses of the “Kainkulak beds” actually represent the Mesoarchean TTGs of the Shevchenko Complex, transformed in the Paleoproterozoic time due to the dislocation metamorphism. The late Paleoarchean (3.3 Ga) tonalites are known in the West Azov and KMA domains; they probably also occur in the basement of the Middle Dnieper domains, where detrital zircons of this age have been reported. These data allow us to assume the existence of a large Late Paleoarchean (3.3 Ga) protocraton, in which the Mesoarchean (3.2-3.0 Ga) greenstone belts and TTGs of the eastern part of the Ukrainian Shield and the KMA Domain were formed.

Detrital chromites reveal Slave craton’s missing komatiite

Geology ◽  
2021 ◽  
Author(s):  
Rasmus Haugaard ◽  
Pedro Waterton ◽  
Luke Ootes ◽  
D. Graham Pearson ◽  
Yan Luo ◽  
...  
Keyword(s):  
Narrow Range ◽  
Thermal Evolution ◽  
Group Element ◽  
Detrital Zircons ◽  
Isotopic Data ◽  
Crust Formation ◽  
Slave Craton ◽  
Provenance Studies ◽  
Juvenile Crust ◽  
Greenstone Belts

Komatiitic magmatism is a characteristic feature of Archean cratons, diagnostic of the addition of juvenile crust, and a clue to the thermal evolution of early Earth lithosphere. The Slave craton in northwest Canada contains >20 greenstone belts but no identified komatiite. The reason for this dearth of komatiite, when compared to other Archean cratons, remains enigmatic. The Central Slave Cover Group (ca. 2.85 Ga) includes fuchsitic quartzite with relict detrital chromite grains in heavy-mineral laminations. Major and platinum group element systematics indicate that the chromites were derived from Al-undepleted komatiitic dunites. The chromites have low 187Os/188Os ratios relative to chondrite with a narrow range of rhenium depletion ages at 3.19 ± 0.12 Ga. While these ages overlap a documented crust formation event, they identify an unrecognized addition of juvenile crust that is not preserved in the bedrock exposures or the zircon isotopic data. The documentation of komatiitic magmatism via detrital chromites indicates a region of thin lithospheric mantle at ca. 3.2 Ga, either within or at the edge of the protocratonic nucleus. This study demonstrates the applicability of detrital chromites in provenance studies, augmenting the record supplied by detrital zircons.

Triassic formations of Mountain ous Crimea: the first resust of U–Pb dating of detrital zircons

2020 ◽  
pp. 18-33
Author(s):  
A. M. Nikishin ◽  
T. V. Romanyuk ◽  
D. V. Moskovskiy ◽  
N. B. Kuznetsov ◽  
A. A. Kolesnikova ◽  
...  
Keyword(s):  
Sedimentary Basin ◽  
Upper Triassic ◽  
Detrital Zircons ◽  
Ukrainian Shield ◽  
Primary Sources ◽  
Two Samples ◽  
Primary Relationships ◽  
First Results ◽  
Different Parts ◽  
Mountainous Crimea

The first results of U-Pb dating of detrital zircons (dZr) from two samples characterizing the Taurica and Eski-Orda Groups of the Cimmerian structural complex of the Mountainous Crimea are presented. The strong similarity of the sets of ages of dZr from the Lower Taurica Formation of the Taurica Group and the Salgir strata of the Eski-Orda Group confirms the facial character of the primary relationships of these Groups. The studied Upper Triassic sandstones had a common feeding province and were formed, most likely, in different parts of the same sedimentary basin. It is most likely that this sedimentary basin was part of a continental margin of Baltica. The presence in samples of a significant number of dZr with very ancient ages >3.0 Ga (including 3 the oldest dZr grains with ages of ~3.9 Ga) makes the crystalline complexes represented in the present-day structure of the Ukrainian Shield as the very possible primary sources of these zircons. Crystalline complexes with such ancient ages are extremely rare over the world, but are widely represented in the Podolian and Cis-Azov blocks of the Ukrainian shield.

scholarly journals Mesoarchean silicic volcanics of the Kursk block, Voronezh crystalline massif: composition, age and correlation with the Ukrainian shield

2019 ◽  
Vol 486 (6) ◽  
pp. 718-722
Author(s):  
K. A. Savko ◽  
A. V. Samsonov ◽  
A. N. Larionov
Keyword(s):  
Geochemical Characteristics ◽  
Ukrainian Shield ◽  
Geological History ◽  
Voronezh Crystalline Massif ◽  
History Of ◽  
Greenstone Belts ◽  
Nd Model Age

Rhyolites and basite rocks are present in the Archaean greenstone belts of the Kursk Domain (KD) of the East Sarmatia. The rhyolite age is 3122 ± 9 Ma (zircons, SIMS). A positive εNd (3122) = + 0.9 for rhyolites and their Sm-Nd model age ТNd (DM) = 3300 Ma as well as the age of the inherited zircon (3250 Ma) testifies to the participation of the more ancient crust component in the formation of rhyolite magmas. In geochemistry, rhyolites are very close to the TTG of the KD with an age 2.96-3.03 Ga. In the Middle Dnieper granite - greenstone area there are rhyolites and dacites with an age of 3.12 Ga with εNd (T) = + 0.6 - (+1.2) and very close geochemical characteristics. Thus, the hypothesis of a common geological history of the eastern part of Ukrainian Shield and KD in Mesoarchean is confirmed.

The age and origin of the North Shore Plutons in the Rae Province, Goldfields area, Saskatchewan

1994 ◽  
Vol 31 (9) ◽  
pp. 1397-1406 ◽  
Author(s):  
David S. O'Hanley ◽  
T. Kurtis Kyser ◽  
Thomas I. I. Sibbald
Keyword(s):  
Detrital Zircons ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
North Shore ◽  
The North ◽  
Evaporation Technique ◽  
Single Zircon ◽  
Archean Crust ◽  
Host Rocks ◽  
Isotope Systematics

The North Shore Plutons are peraluminous granitoids emplaced within the Murmac Bay Group supracrustals exposed on the north shore of Lake Athabasca, Saskatchewan. 207Pb/206Pb ages obtained using the single-zircon Pb-evaporation technique indicate emplacement at 1952 ± 18 Ma, coeval with Taltson magmatism that occurred during the 1.9–2.0 Ga Thelon orogeny, which influenced the Rae Province. The granitoids inherited zircons from Archean source terranes dated at approximately 2.5 and 3.0 Ga. Detrital zircons from the younger source terrane were also identified in the Murmac Bay Group, thus constraining the maximum age of the group to the Paleoproterozoic.Rare earth element and incompatible element data and Rb–Sr and Sm–Nd isotope systematics from the North Shore Plutons and adjacent host rocks indicate that the plutons are crustal melts generated from melting of Murmac Bay Group rocks and Archean crust at deeper levels. Granitic gneisses described as "Older" Granites represent mixtures of variable amounts of magmatic fluids similar to those that formed the North Shore plutons and the Murmac Bay Group metasedimentary rocks.

Structural tests of diapir hypotheses in Archean crust of Ontario

1990 ◽  
Vol 27 (3) ◽  
pp. 387-402 ◽  
Author(s):  
W. M. Schwerdtner
Keyword(s):  
Solid State ◽  
Horizontal Displacement ◽  
Gneiss Dome ◽  
Gneiss Domes ◽  
Archean Crust ◽  
Structural Tests ◽  
Greenstone Belts ◽  
Ductile Shear

Detailed structural maps of two granitoid complexes in the Wabigoon Subprovince are used to test three diapir hypotheses advanced in earlier papers. The gneiss masses of, and individual domes within, the complexes fail the test for solid-state diapirism. The gneiss domes also fail the test for tensile bending caused by hypothetical magmatic diapirs in the subsurface. An oval pluton located near the best-exposed gneiss dome proves to be a synformal sheet rather than a funnel-shaped magmatic diapir. This pluton could be a syenite–diorite phacolith emplaced into a concordant zone of dilation during the late upright folding of the gneiss mass about horizontal axes. Earlier tight folds were probably recumbent and south verging and, like the gneissosity, generated in a ductile shear regime with subhorizontal glide planes. These observations have important implications for Archean tectonics, especially the relative horizontal displacement of large greenstone masses (potentially allochthonous greenstone belts).

Relationships between granite-gneiss terrains, greenstone belts and granulite belts in the archean crust of Lapland (Fennoscandia)

1980 ◽  
Vol 69 (3) ◽  
pp. 648-658 ◽  
Author(s):  
P. Barbey ◽  
J. Convert ◽  
H. Martin ◽  
B. Moreau ◽  
R. Capdevila ◽  
...  
Keyword(s):  
Granite Gneiss ◽  
Archean Crust ◽  
Greenstone Belts
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