scholarly journals U-Pb zircon age of the pegmatoid of the Muong Lat complex

2019 ◽  
Vol 2 (1) ◽  
pp. 96-101
Author(s):  
Tran Van Thanh ◽  
Pham Trung Hieu
Keyword(s):  
Continental Crust ◽  
Material Composition ◽  
Zircon Core ◽  
Zircon Age ◽  
Analytical Results ◽  
Icp Ms ◽  
Granitoid Complex

Muong Lat granitoid complex located in Thanh Hoa province. It is composed of two mica granite, aplite and pegmatoid. Rock forming minerals include mainly K-feldspar, quartz biotite and muscovite. Crystallization age of pegmatite in Muong Lat body is determined by U-Pb zircon LA-ICP-MS method. Most of the analytical results 206Pb age / 238U ranged from 217–238 Ma, average 230 ± 7 Ma. Age results indicate, the existence magma activity in the study area. Three inherited zircon core gaves age of ~2.8Ga, ~2.4Ga, ~1.8Ga, ~400Ma and ~750 Ma, suggesting that the continental crust of the study area including material composition of the Neoarchean, Paleoproterozoic, Paleozoic and Neoproterozoic

scholarly journals The LA-ICP-MS U-Pb zircon age of rhyolite from the Dong Trau formation and its geological significances

2018 ◽  
Vol 1 (T5) ◽  
pp. 270-277
Author(s):  
Hieu Trung Pham
Keyword(s):  
Primary Magma ◽  
Early Triassic ◽  
Late Permian ◽  
Weighted Mean ◽  
Zircon Age ◽  
Analytical Results ◽  
Icp Ms ◽  
Magma Crystallization ◽  
Sr Method

Zircons separated from an rhyolite sample in the Dong Trau formation, in the southern of Hà Tĩnh province were dated to determine the protolith age for the complex. Sixteen LA-ICP-MS U-Pb zircon analyses give concordant ages concentrated at 256 Ma (weighted mean). These results indicate the protolith age of the rhyolite (primary magma crystallization age). The value of this age are close to the analytical results pf the whole rock by Rb-Sr method and biotite Rb-Sr method. Therefore the crystallization age of the rhyolite from the Đồng Trầu formation corresponded period late Permian to early Triassic.

Caledonian terrane amalgamation of Svalbard: detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen

2013 ◽  
Vol 150 (6) ◽  
pp. 1103-1126 ◽  
Author(s):  
DETA GASSER ◽  
ARILD ANDRESEN
Keyword(s):  
Detrital Zircon ◽  
Large Scale ◽  
Strike Slip ◽  
Western Coast ◽  
Zircon Age ◽  
The North ◽  
Tectonic History ◽  
Icp Ms ◽  
Depositional Age ◽  
Sveconorwegian Orogen

AbstractThe tectonic origin of pre-Devonian rocks of Svalbard has long been a matter of debate. In particular, the origin and assemblage of pre-Devonian rocks of western Spitsbergen, including a blueschist-eclogite complex in Oscar II Land, are enigmatic. We present detrital zircon U–Pb LA-ICP-MS data from six Mesoproterozoic to Carboniferous samples and one U–Pb TIMS zircon age from an orthogneiss from Oscar II Land in order to discuss tectonic models for this region. Variable proportions of Palaeo- to Neoproterozoic detritus dominate the metasedimentary samples. The orthogneiss has an intrusion age of 927 ± 3 Ma. Comparison with detrital zircon age spectra from other units of similar depositional age within the North Atlantic region indicates that Oscar II Land experienced the following tectonic history: (1) the latest Mesoproterozoic sequence was part of a successor basin which originated close to the Grenvillian–Sveconorwegian orogen, and which was intruded byc. 980–920 Ma plutons; (2) the Neoproterozoic sediments were deposited in a large-scale basin which stretched along the Baltoscandian margin; (3) the eclogite-blueschist complex and the overlying Ordovician–Silurian sediments probably formed to the north of the Grampian/Taconian arc; (4) strike-slip movements assembled the western coast of Spitsbergen outside of, and prior to, the main Scandian collision; and (5) the remaining parts of Svalbard were assembled by strike-slip movements during the Devonian. Our study confirms previous models of complex Caledonian terrane amalgamation with contrasting tectonic histories for the different pre-Devonian terranes of Svalbard and particularly highlights the non-Laurentian origin of Oscar II Land.

A mid-Palaeozoic ocean–continent transition in the Mazongshan subduction–accretion complex, Beishan, NW China: new structural, chemical and age data constrain the petrogenesis and tectonic evolution

2020 ◽  
Vol 157 (11) ◽  
pp. 1877-1897 ◽  
Author(s):  
J.-X. Wang ◽  
K.-X. Zhang ◽  
Brian F. Windley ◽  
B.-W. Song ◽  
X.-H. Kou ◽  
...  
Keyword(s):  
Continental Crust ◽  
Early Carboniferous ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Published Data ◽  
Zircon Age ◽  
The North ◽  
Tectonic History ◽  
Central Asian ◽  
Tectonic Mélange

AbstractAccretionary orogens contain key evidence for the conversion of oceanic to continental crust. The late tectonic history and closure time of the Palaeo-Asian Ocean are recorded in the Mazongshan subduction–accretion complex in the southern Beishan margin of the Central Asian Orogenic Belt. We present new data on the structure, petrology, geochemistry and zircon U–Pb isotope ages of the Mazongshan subduction–accretion complex, which is a tectonic mélange with a block-in-matrix structure. The blocks are of serpentinized peridotite, basalt, gabbro, basaltic andesite, chert and seamount sediments within a matrix that is mainly composed of fore-arc-trench turbidites. U–Pb zircon ages of two gabbros are 454.6 ± 2.5 Ma and 434.1 ± 3.6 Ma, an andesite has a U–Pb zircon age of 451.3 ± 3.5 Ma and a tuffaceous slate has the youngest U–Pb zircon age of 353.6 ± 5.1 Ma. These new isotopic ages, combined with published data on ophiolitic mélanges from central Beishan, indicate that the subduction–accretion of Beishan in the southernmost Central Asian Orogenic Belt lasted until Late Ordovician – Early Carboniferous time. Structure and age data demonstrate that the younging direction of accretion was southwards and that the subduction zone dipped continuously to the north. Accordingly, these results record the conversion of oceanic to continental crust in the southern Beishan accretionary collage.

scholarly journals U-Pb zircon age of the youngest magmatic activity in the High Tatra granites (Central Western Carpathians)

2013 ◽  
Vol 40 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Jolanta Burda ◽  
Aleksandra Gawęda ◽  
Urs Klötzli
Keyword(s):  
Inductively Coupled Plasma ◽  
Age Groups ◽  
Hydrothermal Activity ◽  
Magmatic Activity ◽  
Zircon Age ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Central Western Carpathians ◽  
High Tatra Mountains

Abstract Detailed cathodoluminescence (CL) imaging of zircon crystals, coupled with Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) U-Pb zircon dating was used to develop new insights into the evolution of granitoids from the High Tatra Mountains. The zircon U-Pb results show two distinct age groups (350±5 Ma and 337±6 Ma) recorded from cores and rims domains, respectively. Obtained results point that the last magmatic activity in the Tatra granitoid intrusion occurred at ca. 330 Ma. The previously suggested age of 314 Ma reflects rather the hydrothermal activity and Pb-loss, coupled with post-magmatic shearing.

High spatial resolution in situ U–Pb dating using laser ablation multiple ion counting inductively coupled plasma mass spectrometry (LA-MIC-ICP-MS)

2017 ◽  
Vol 32 (5) ◽  
pp. 975-986 ◽  
Author(s):  
Lie-Wen Xie ◽  
Jin-Hui Yang ◽  
Qing-Zhu Yin ◽  
Yue-Heng Yang ◽  
Jing-Bo Liu ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Inductively Coupled Plasma ◽  
High Spatial Resolution ◽  
Zircon Age ◽  
Analytical Technique ◽  
Inductively Coupled ◽  
Rapid Measurement ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

A new LA-MIC-ICP-MS analytical technique has been developed for the rapid measurement of 206Pb/238U zircon age (<1%, 2s) at a high spatial resolution. We show that this technique can be routinely employed to date U–Pb in small and/or complex zircons, providing a powerful tool for geochronology.

U-Pb dating, oxygen and hafnium isotopic ratios of zircon from rocks of oceanic core complexes at Mid-Atlantic Ridge: evidence for an interaction of young and ancient crusts at spreading of the ocean floor

2019 ◽  
Vol 489 (5) ◽  
pp. 483-489
Author(s):  
N. S. Bortnikov ◽  
S. А. Silantiev ◽  
F. Bea ◽  
P. Montero ◽  
T. F. Zinger ◽  
...  
Keyword(s):  
Continental Crust ◽  
Oceanic Crust ◽  
Isotopic Ratio ◽  
Ocean Floor ◽  
Isotopic Ratios ◽  
Icp Ms ◽  
Different Ages ◽  
Mid Atlantic Ridge ◽  
Slow Spreading ◽  
Central Atlantic

U-Pb age, oxygen and hafnium isotopic ratios in zircon from rocks of ocean core complexes at Mid-Atlantic Ridge have been studied using SHRIMP and MC-LA-ICP-MS techniques. U-Pb dating revealed four group of zircons: 1) 0,6-1,7 Ma, 2) 6,7-11,2 Ma, 3) 12,9-17,6 Ma, 4) 200 to 2044 Ma. The 18O values range from 4,74 to 7,2 and are distinct for zircon grains of different ages. Hafnium isotopic ratio for zircon aged from 0,6 to 17,6 Ma corresponds or is close to that of MORB from Central Atlantic. The oxygen and hafnium isotopic compositions of zircon elder than 280 Ma correspond to those of the sialic continental crust. A hypothesis of involvement of the ancient pre-Atlantic sialic (280 млн лет) and old Atlantic (7-17 Ma) crusts in a generation of the contemporary (young) oceanic crust during formation of the slow-spreading Mid-Atlantic Ridge has been proposed.

scholarly journals Zircon age peaks: Production or preservation of continental crust?

Geosphere ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Kent C. Condie ◽  
Nicholas Arndt ◽  
Anne Davaille ◽  
Stephen J. Puetz
Keyword(s):  
Continental Crust ◽  
Zircon Age

U–Pb dating of CA/non-CA treated zircons obtained by LA-ICP-MS and CA-TIMS techniques: impact for their geological interpretation

2014 ◽  
Vol 29 (9) ◽  
pp. 1618-1629 ◽  
Author(s):  
A. von Quadt ◽  
D. Gallhofer ◽  
M. Guillong ◽  
I. Peytcheva ◽  
M. Waelle ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Precision ◽  
Isotope Dilution ◽  
Thermal Ionization Mass Spectrometry ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Zircon Age ◽  
Geological Interpretation ◽  
Icp Ms ◽  
Thermal Ionization Mass

Chemical Abrasion Isotope-Dilution Thermal Ionization Mass Spectrometry (CA-ID-TIMS) is known as a high precision technique for resolving lead loss and improving the interpretation of U–Pb zircon age data.

scholarly journals Subduction of a rifted passive continental margin: the Pohorje case of Eastern Alps–constraints from geochronology and geochemistry

2020 ◽  
Vol 113 (1) ◽  
Author(s):  
Ruihong Chang ◽  
Franz Neubauer ◽  
Yongjiang Liu ◽  
Johann Genser ◽  
Wei Jin ◽  
...  
Keyword(s):  
Continental Crust ◽  
Rift Zone ◽  
Eastern Alps ◽  
Granitic Magma ◽  
Geochemical Data ◽  
Icp Ms ◽  
Hp Metamorphism ◽  
Two Samples ◽  
Ultramafic Cumulates ◽  
T Values

Abstract This study presents geochronological and geochemical data from newly dated Permian granitic orthogneisses associated with the Eclogite-Gneiss unit (EGU) from the southernmost part of the Austroalpine nappe stack, exposed within the Pohorje Mountains (Slovenia). LA-ICP-MS zircon U–Pb ages of two samples of the augen-gneisses are 255 ± 2.2 Ma and 260 ± 0.81 Ma, which are interpreted as the age of magmatic crystallization of zircon. In contrast, all round zircons from leucogneisses give Cretaceous ages (89.3 ± 0.7 Ma and 90.8 ± 1.2 Ma), considered as the age of UHP/HP metamorphism. The round zircons overgrew older euhedral zircons of Permian and rare older ages tentatively indicating that these rocks are of latest Permian age, too. Zircon εHf(t) values of the four orthogneiss samples are between − 13.7 and − 1.7 with an initial 176Hf/177Hf ratio ranging from 0.282201 to 0.282562; T DM C is Proterozoic. The augen-gneisses show geochemical features, e.g. high (La/Lu)N ratios and strong negative Eu anomalies, of an evolved granitic magma derived from continental crust. The leucogneisses are more heterogeneously composed and are granitic to granodioritic in composition and associated with eclogites and ultramafic cumulates of oceanic affinity. We argue that the Permian granitic orthogneisses might be derived from partial melting of lower crust in a rift zone. We consider, therefore, that segment of the EGU is part of the distal Late Permian rift zone, which finally led to the opening of the Meliata Ocean during Middle Triassic times. If true, the new data also imply that the Permian stretched continental crust was potentially not much wider than ca. 100 km, was subducted and then rapidly exhumed during early Late Cretaceous times.

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