scholarly journals Zircon of Triassic Age in the Stuttgart Formation (Schilfsandstein)—Witness of Tephra Fallout in the Central European Basin and New Constraints on the Mid-Carnian Episode

2021 ◽  
Vol 9 ◽  
Author(s):  
Armin Zeh ◽  
Matthias Franz ◽  
Karsten Obst
Keyword(s):  
Weighted Average ◽  
Central European ◽  
Fluvial Erosion ◽  
Central European Basin ◽  
Environmental Perturbations ◽  
Icp Ms ◽  
Southern Central ◽  
Single Zircon ◽  
Depositional Age ◽  
Tephra Fallout

The Carnian Stuttgart-Formation (Schilfsandstein) of the Central European Basin contains relics of Triassic volcanic detritus in form of euhedral zircon grains and authigenic analcime. Multiple LA-ICP-MS spot analyses of single zircon crystals from an outcrop near Heilbronn (SW Germany) yielded weighted average 206Pb/238U ages between 250 and 230 Ma, providing evidence for tephra fallout in the southern part of the Central European Basin related to Olenekian, Anisian–Ladinian and Carnian volcanic activity. The tephra was probably transported by monsoonal circulations from volcanic centres of the NW Tethys to the Central European Basin. The four youngest zircon crystals gave a weighted average 206Pb/238U age of 231.1 ± 1.6 Ma (10 analyses), which is interpreted to date syn-depositional tephra fallout into the fluvial Lower Schilfsandstein Member of the Stuttgart Formation. This new maximum depositional age provides the first evidence that deposition of the Stuttgart Formation, which represents the type-example of the mid-Carnian episode, a global episode of enhanced flux of siliciclastic detritus and related environmental perturbations, occurred during the Tuvalian 2 substage at ca. 231 Ma, about 3 million years later than suggested by previous correlations. Zircon grains with weighted average 206Pb/238U ages of 236.0 ± 1.2 Ma (n = 17) and 238.6 ± 1.5 Ma (n = 6) and 206Pb/238U ages between 241 ± 6 and 250 ± 3 Ma point to the presence of tephra in early Carnian to Olenekian strata of the Keuper to Buntsandstein Groups. Traces of these reworked tephra were incorporated into the Stuttgart Formation due to fluvial erosion in the southern Central European Basin and at its margins.

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.

scholarly journals The Paleoproterozoic Kandalaksha-Kolvitsa Gabbro-Anorthosite Complex (Fennoscandian Shield): New U–Pb, Sm–Nd, and Nd–Sr (ID-TIMS) Isotope Data on the Age of Formation, Metamorphism, and Geochemical Features of Zircon (LA-ICP-MS)

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 254 ◽  
Author(s):  
Ekaterina N. Steshenko ◽  
Tamara B. Bayanova ◽  
Pavel A. Serov
Keyword(s):  
Inductively Coupled Plasma ◽  
Early Stage ◽  
Crustal Contamination ◽  
Inductively Coupled ◽  
Granulite Metamorphism ◽  
Icp Ms ◽  
Zircon Crystallization ◽  
Mantle Reservoir ◽  
Single Zircon ◽  
Anorthosite Complex

The paper provides new U–Pb, Sm–Nd, and Nd–Sr isotope-geochronological data on rocks of the Paleoproterozoic Kandalaksha-Kolvitsa gabbro-anorthosite complex. Rare earth element (REE) contents in zircons from basic rock varieties of the Kandalaksha-Kolvitsa area were analyzed in situ using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Plots of REE distribution were constructed, confirming the magmatic origin of zircon. Temperatures of zircon crystallization were estimated using a Ti-in-zircon geochronometer. The U–Pb method with a 205Pb artificial tracer was first applied to date single zircon grains (2448 ± 5 Ma) from metagabbro of the Kolvitsa massif. The U–Pb analysis of zircon from anorthosites of the Kandalaksha massif dated the early stage of the granulite metamorphism at 2230 ± 10 Ma. The Sm–Nd isotope age was estimated on metamorphic minerals (apatite, garnet, sulfides) and whole rock at 1985 ± 17 Ma (granulite metamorphism) for the Kolvitsa massif and at 1887 ± 37 Ma (high-temperature metasomatic transformations) and 1692 ± 71 Ma (regional fluid reworking) for the Kandalaksha massif. The Sm–Nd model age of metagabbro was 3.3 Ga with a negative value of εNd = 4.6, which corresponds with either processes of crustal contamination or primary enriched mantle reservoir of primary magmas.

New fossil insects from the Anisian (Lower to Middle Muschelkalk) from the Central European Basin (Germany and The Netherlands)

PalZ ◽  
2017 ◽  
Vol 91 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Timo van Eldijk ◽  
Gerard Goris ◽  
Adam Haarhuis ◽  
Jos Lankamp ◽  
Herman Winkelhorst ◽  
...  
Keyword(s):  
The Netherlands ◽  
Fossil Insects ◽  
Central European ◽  
Central European Basin

scholarly journals Supplemental Material: Recalibrating Rodinian rifting in the northwestern United States

2021 ◽  
Author(s):  
Daniel Brennan ◽  
et al.
Keyword(s):  
United States ◽  
Mass Spectrometry ◽  
Detrital Zircon ◽  
Inductively Coupled Plasma ◽  
Individual Sample ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Depositional Age ◽  
Conventional Laser

Individual sample detrital zircon results, alternative maximum depositional age calculations, conventional laser-ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) methodology, rapid LA-ICP-MS methodology, sample locations, and detrital zircon U-Pb/Lu-Hf results for all analyses and compiled U-Pb data.<br>

scholarly journals BACIA PRECURSORA VERSUS BACIAS OROGÊNICAS: EXEMPLOS DO GRUPO ANDRELÂNDIA COM BASE EM DATAÇÕES U-PB (LA-ICP-MS) EM ZIRCÃO E ANÁLISES LITOQUÍMICAS

2013 ◽  
Author(s):  
Juliane Belém ◽  
Antônio Carlos Pedrosa-Soares ◽  
Carlos Maurício Noce ◽  
Luiz Carlos Da Silva ◽  
Richard Armstrong ◽  
...  
Keyword(s):  
Passive Margin ◽  
High Grade ◽  
Boundary Zone ◽  
Sediment Sources ◽  
The West ◽  
Stratigraphic Unit ◽  
Type Area ◽  
Icp Ms ◽  
Depositional Age ◽  
Analysis Point

Resultados de datações U-Pb (LA-ICP-MS) sobre zircões e análises litoquímicas de amostras de paragnaisse e xisto do Grupo Andrelândia, coletadas desde sua área-tipo até a região de alto grau metamórfico do sistema orogênico Araçuaí-Ribeira, evidenciam que esta extensa unidade estratigráfica inclui representantes de bacia precursora de margem continental passiva, representada pelo Grupo Andrelândia Inferior (paragnaisse de Madre de Deus, Seqüência Carrancas), com idade máxima em ca. 950 Ma e fontes sedimentares diversificadas, datadas do Toniano ao Neoarqueano; e de bacias orogênicas, representadas pela Unidade Santo Antônio do Grupo Andrelândia Superior e paragnaisses de alto grau metamórfico da região de Ubá-Carangola, com idade máxima em torno de 640 Ma e extrema concentração de áreas-fontes neoproterozóicas. As análises litoquímicas apontam para larga predominância de fontes sedimentares situadas em arcos magmáticos, mas a amostra que melhor indica a bacia precursora (o paragnaisse de Madre de Deus, Seqüência Carrancas) tem assinatura similar a depósitos de margem continental passiva. Amostras de paragnaisse migmatítico revelam a idade de ca. 565 Ma para o clímax metamórfico-anatético na zona de fronteira Araçuaí-Ribeira. Destaca-se que o Grupo Andrelândia Superior, na forma como é representado em mapas atuais, incluiria pelo menos duas bacias orogênicas, i.e., uma, na Faixa Brasília e, outra, no sistema Araçuaí-Ribeira.Palavras-chave: geocronologia U-Pb, litoquímica, Grupo Andrelândia ABSTRACT: PRECURSOR BASIN VERSUS OROGENIC BASINS: EXAMPLES FROM THE ANDRELÂNDIA GROUP BASED ON ZIRCON U-Pb (LA-ICP-MS) AND LITHOCHEMICAL ANALYSIS. Results from zircon U-Pb (LA-ICP-MS) and lithochemical analysis on samples from the Andrelândia Group, collected from its type-area to the high grade core of the Araçuaí-Ribeira orogenic system, suggest that this extensive stratigraphic unit includes a precursor passive margin basin, represented by the Lower Andrelândia Group (Madre de Deus paragneiss, Carrancas sequence), with maximum depositional age around 950 Ma and diversified sediment sources dated from the Tonian to Neoarchean; and orogenic basin(s), represented by the Santo Antônio unit of the Upper Andrelândia Group and high grade paragneisses of the Ubá-Carangola region, with a maximum depositional age around 640 Ma and provenance extremely restricted to Neoproterozoic sources. Lithochemical analysis point to a large predominance of sediment sources located in magmatic arcs, but the sample representing the precursor basin shows signature similar to passive margin deposits. High grade paragneisses reveal the age of ca. 565 Ma to the metamorphic-anatectic climax in the Araçuaí-Ribeira boundary zone. It is important to notice that the Upper Andrelândia Group, as represented in current maps, includes at least two orogenic basins, i.e., the older, to the west, in the Brasília belt, and the younger, to the east, in the Araçuaí-Ribeira system.Keywords: U-Pb geochronology, lithochemistry, Andrelândia Group.

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