scholarly journals SHRIMP U-Pb dating of detrital zircons in metamorphic rocks from northern Kyushu, western Japan

2003 ◽  
Vol 98 (5) ◽  
pp. 181-193 ◽  
Author(s):  
Yukiyasu TSUTSUMI ◽  
Kazumi YOKOYAMA ◽  
Kentaro TERADA ◽  
Yuji SANO
Keyword(s):  
Detrital Zircons ◽  
Metamorphic Rocks ◽  
Western Japan

scholarly journals SHRIMP U-Pb dating of detrital zircons in paragneiss from Oki-Dogo Island, western Japan

2006 ◽  
Vol 101 (6) ◽  
pp. 289-298 ◽  
Author(s):  
Yukiyasu TSUTSUMI ◽  
Kazumi YOKOYAMA ◽  
Kenji HORIE ◽  
Kentaro TERADA ◽  
Hiroshi HIDAKA
Keyword(s):  
Detrital Zircons ◽  
Western Japan

The Duration and Geodynamics of Formation of the Angara–Vitim Batholith: Results of U–Pb Isotope (LA-ICP-MS) Dating of Magmatic and Detrital Zircons

2021 ◽  
Vol 62 (12) ◽  
pp. 1331-1349
Author(s):  
V.B. Khubanov ◽  
A.A. Tsygankov ◽  
G.N. Burmakina
Keyword(s):  
Drainage Basin ◽  
Detrital Zircons ◽  
Late Paleozoic ◽  
Metamorphic Rocks ◽  
Zircon Geochronology ◽  
Geochronological Data ◽  
Pb Isotope ◽  
Alluvial Deposits ◽  
Detrital Zircon Geochronology ◽  
Icp Ms

Abstract —We present results of U–Pb (LA-ICP-MS) dating of detrital zircons from the alluvial deposits of the Angarakan River (North Muya Ridge, northern Baikal region), whose drainage basin is composed mainly of granitoids of the Barguzin Complex, typomorphic for the late Paleozoic Angara–Vitim batholith (AVB). Three age clusters with peaks at 728, 423, and 314 Ma have been identified in the studied population of detrital zircons. It is shown that small outliers of igneous and metamorphic rocks, probably similar to the large AVB roof pendants mapped beyond the drainage basin, are the source of Neoproterozoic and early Paleozoic zircons. The late Paleozoic cluster comprises two close peaks at 314 and 28 Ma, which totally “overlap” with the time of the AVB formation and mark a granitoid source of the zircons. The results of detrital-zircon geochronology, together with the data on bedrocks, point to the prolonged (~40 Myr) formation of the AVB, but the intensity of magmatism during this period calls for additional study. Based on the analysis of published geological, geochemical, and geochronological data, we assume that the AVB resulted from the plume–lithosphere interaction that began in the compression setting and gave way to extension 305–300 Ma (the Carboniferous–Permian boundary), which caused replacement of “crustal” granitoids by granitoids formed from a mixed mantle–crustal source.

The geochronology of some stratified metamorphic rocks in northeastern Massachusetts

1980 ◽  
Vol 17 (10) ◽  
pp. 1407-1416 ◽  
Author(s):  
William J. Olszewski Jr.
Keyword(s):  
New England ◽  
Source Area ◽  
Detrital Zircons ◽  
Metamorphic Rocks ◽  
Thermal Event ◽  
Northwest Africa ◽  
Major Period

Analyses of U and Pb in zircons and Rb and Sr in whole rocks have been made on stratified metamorphic rocks in northeastern Massachusetts. The Rb–Sr results show an age of about 450 Ma, which is interpreted as a resetting age. This would indicate the major period of metamorphism in the area. Zircons from the Fishbrook Gneiss give an upper intercept age of 730 ± 26 Ma, which is interpreted as the age of volcanism that produced the Fishbrook Gneiss sequence. The upper intercept of the Westboro Formation detrital zircons is 1511 ± 22 Ma and is interpreted as the age of the source for the Westboro sediments. The lower intercepts of the Fishbrook (289 Ma) and the Westboro (278 Ma) zircons suggest an episodic Pb loss correlated with the thermal event in southeastern New England recognized by other methods. The intercept ages of the Shawsheen Gneiss (2042 and 517 Ma) are more difficult to interpret, but also suggest an old source area. This source area is tentatively suggested to be northwest Africa.

Sinistral transport along the Trans-European Suture Zone: detrital zircon–rutile geochronology and sandstone petrography from the Carboniferous flysch of the Pontides

2010 ◽  
Vol 148 (3) ◽  
pp. 380-403 ◽  
Author(s):  
NİLGÜN OKAY ◽  
THOMAS ZACK ◽  
ARAL I. OKAY ◽  
MATTHIAS BARTH
Keyword(s):  
Central Europe ◽  
Detrital Zircon ◽  
Early Carboniferous ◽  
Suture Zone ◽  
Detrital Zircons ◽  
Metamorphic Rocks ◽  
Late Devonian ◽  
Lower Carboniferous ◽  
Clastic Rocks ◽  
Sandstone Petrography

AbstractThe Lower Carboniferous flysch of the Istanbul Zone in Turkey is an over 1500 m thick turbiditic sandstone–shale sequence marking the onset of the Variscan deformation in the Pontides. It overlies Lower Carboniferous black cherts and is unconformably overlain by Lower Triassic continental sandstones and conglomerates. The petrography of the Carboniferous sandstones and the geochronology and geochemistry of the detrital zircons and rutiles were studied to establish the provenance of the clastic rocks. The sandstones are feldspathic to lithic greywackes and subgreywackes with approximately equal amounts of quartz, feldspar and lithic clasts. The amount of quartz and lithic fragments decreases upwards in the sequence at the expense of feldspar. The lithic fragments are dominated by intermediate volcanic rocks, followed by metamorphic and sedimentary rock fragments. Coarse lithic fragments are generally granitoidic. In the discrimination diagrams, sandstone samples lie mainly in the field of dissected arc. A total of 218 detrital zircons and 35 detrital rutiles from four sandstone samples were analysed with laser ablation ICP-MS. The detrital zircons show a predominantly bimodal age distribution with Late Devonian to Early Carboniferous (390 to 335 Ma) and Cambrian–Neoproterozoic (640 to 520 Ma) ages. The remaining 9 % of the analysed zircons are in the 1700–2750 Ma range; zircons of the 700–1700 Ma age range are absent. The REE patterns and Th/U ratios of the zircons are consistent with a magmatic origin. With one exception (Neoproterozoic), the rutile ages are Late Devonian–Early Carboniferous and their geochemistry indicates that they were derived from amphibolite-facies metamorphic rocks. Sandstone petrography and detrital zircon–rutile ages suggest one dominant source for the Lower Carboniferous sandstones: a Late Devonian to Early Carboniferous magmatic and metamorphic province with overprinted Neoproterozoic basement. Late Devonian–Early Carboniferous magmatic and metamorphic rocks are unknown from the Eastern Mediterranean region. They are, however, widespread in central Europe. The Istanbul Zone is commonly correlated with the Avalonian terrranes in central Europe, which collided with the Armorican terranes during Carboniferous times, resulting in the Variscan orogeny. The Carboniferous flysch of the Istanbul Zone must have been derived from a colliding Armorican terrane, as indicated by the absence of 700–1700 Ma zircons and by Late Devonian–Early Carboniferous magmatism, typical features of the Armorican terranes. This suggests that during Carboniferous times the Istanbul terrane was located close to the Bohemian Massif and has been translated by strike-slip along the Trans-European Suture Zone to its Cretaceous position north of the Black Sea.

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 Ultramafic rocks in the North Patagonian Andes: is their emplacement associated with the Neogene tectonics of the Liquiñe–Ofqui Fault Zone?

2017 ◽  
Vol 44 (1) ◽  
pp. 1 ◽  
Author(s):  
Francisco Hervé ◽  
Francisco José Fuentes ◽  
Mauricio Calderón ◽  
Mark Fanning ◽  
Paulo Quezada ◽  
...  
Keyword(s):  
Fault Zone ◽  
Detrital Zircons ◽  
Ultramafic Rocks ◽  
Metamorphic Rocks ◽  
Western Slope ◽  
Low Grade ◽  
Flower Structure ◽  
The North ◽  
Patagonian Andes ◽  
Forearc Region

Serpentinites and fresh or partially serpentinized harzburgite crop out in the western slope of the North Patagonian Andes of continental Chiloé (41°44’-42°12’S). These rocks are spatially associated with low-grade metamorphic rocks containing Cenozoic detrital zircons. The metamorphic rocks, together with Devonian metasediments, have been mapped previously as Late Paleozoic-Triassic metamorfic complex, an age no longer tenable for at least part of the complex. Transpressional tectonic emplacement of the ultramafic body or bodies is thought to have been related to activity on the Liquiñe-Ofqui Fault Zone, following a late Oligocene-Early Miocene extensional phase in the forearc region of the present Andes. This fault zone occurs immediately east of the outcrops of the ultramafic rocks and has been interpreted previously as generating a hemi-flower or flower structure.

scholarly journals Distribution of zircon age values in metamorphic rocks within the Taratash block of the Southern Urals (initial provenance signal)

2017 ◽  
pp. 15-19
Author(s):  
Al. V. Tevelev ◽  
V. M. Mosejchuk ◽  
A. V. Tevelev ◽  
B. B. Shkursky
Keyword(s):  
Southern Urals ◽  
Detrital Zircons ◽  
Metamorphic Rocks ◽  
The Southern Urals ◽  
Zircon Age ◽  
Lower Riphean ◽  
Kolmogorov Smirnov ◽  
Definition Of ◽  
Isotope Dating ◽  
Smirnov Test

The article establishes and realizes an idea of definition of the initial provenance signal for the Southern Urals Taratash block using isotope dating of the zircons in the Archean and Early Proterozoic magmatic and metamorphic rocks. The work takes into account 132 data for which the discordance did not exceed 10%. We obtained a probability density diagram for zircon ages, which we used firstly for comparison with detrital zircons ages from the sandstones of lower riphean Ay suite, and secondly, with density of the zircon ages in the metamorphic rocks of the Aleksandrovsky block located to the east. The similarity of distributions was verified by means of the Kolmogorov-Smirnov test.

scholarly journals Mid-Cenozoic SHRIMP U-Pb detrital zircon ages from metasedimentary rocks in the North Patagonian Andes of Aysén, Chile

2021 ◽  
Vol 48 (1) ◽  
pp. 54
Author(s):  
Paulo Quezada ◽  
Francisco Hervé ◽  
Mauricio Calderón ◽  
Mark Fanning ◽  
Robert Pankhurst ◽  
...  
Keyword(s):  
High Energy ◽  
Detrital Zircons ◽  
Metamorphic Rocks ◽  
Low Grade ◽  
Metasedimentary Rocks ◽  
The North ◽  
Metamorphic Basement ◽  
Facies Variation ◽  
Detrital Zircon Ages ◽  
Patagonian Andes

Previously undated low-grade metamorphic rocks from the Puerto Cisnes-Queulat area (44°30’ S) contain detrital zircons of mid-Oligocene age (ca. 28 Ma). Their outcrops represent the easternmost occurrence of the late Oligocene to early Miocene marine volcano-sedimentary Traiguén Formation; previous correlation with the Paleozoic metamorphic basement of this sector of the North Patagonian Andes is thus refuted. A similar age and provenance were obtained for a paraconglomerate bed of the La Junta Formation ca. 80 km to the north, which is thought to represent a high-energy lateral facies variation of the Traiguén Formation. Miocene plutonic rocks of the North Patagonian Batholith intruded these metasedimentary rocks, generating a contact metamorphic aureole that reaches biotite grade and overprints a previous metamorphic fabric probably formed during closure of the Traiguén Basin. Similar young ages for metamorphic rocks located immediately west of the Liquiñe-Ofqui Fault Zone 300 km north, near Ayacara, suggest a regional pattern of earliest Neogene metamorphism and rapid exhumation in this segment of the Patagonian Andes.

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