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.

Fe–Si-oxyhydroxide deposits at a slow-spreading centre with thickened oceanic crust: The Lilliput hydrothermal field (9°33′S, Mid-Atlantic Ridge)

2010 ◽  
Vol 278 (3-4) ◽  
pp. 186-200 ◽  
Author(s):  
Vesselin M. Dekov ◽  
Sven Petersen ◽  
C.-Dieter Garbe-Schönberg ◽  
George D. Kamenov ◽  
Mirjam Perner ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Hydrothermal Field ◽  
Mid Atlantic Ridge ◽  
Slow Spreading

scholarly journals Implication of Mineralogy and Isotope Data on the Origin of the Permian Basic Volcanic Rocks of the Hronicum (Slovakia, Western Carpathians)

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 841
Author(s):  
Ján Spišiak ◽  
Anna Vozárová ◽  
Jozef Vozár ◽  
Štefan Ferenc ◽  
Viera Šimonová ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mineral Composition ◽  
Mantle Source ◽  
Isotopic Ratio ◽  
Volcanic Rocks ◽  
Geochemical Data ◽  
Isotopic Ratios ◽  
Icp Ms ◽  
Primary Mineral ◽  
Basic Volcanic

The paper presents new geochemical data of the basic to intermediate volcanic rocks from the Hronic unit. The studied rocks are strongly altered and the primary mineral composition (clinopyroxenes, amphiboles, spinels, biotites, and plagioclases) is preserved only in some localities. The clinopyroxene corresponds to augite and primary amphiboles to pargasites. Spinels have a chemical composition similar to spinels from volcanic rocks. According to chemical composition, the studied basalts correspond to rift-related continental tholeiites. 143Nd/144Nd vs. 87Sr/86Sr isotopic ratios of the basalts are scattered around the value of 143Nd/144Nd for CHUR, where 143Nd/144Nd ratios are relatively stable and 87Sr/86Sr values are relatively varied. According to isotopic ratio of 207Pb/204Pb vs. 206Pb/204Pb, the basalt analyses lie in the field of EMII (mantle source enriched with crustal materials). The new results of U-Pb LA-ICP-MS dating of apatite point to an age 254 ± 23 Ma (Lopingian).

scholarly journals 87Sr/86Sr isotopic ratios in vineyard soils and varietal wines from Douro Valley

2019 ◽  
Vol 12 ◽  
pp. 02031
Author(s):  
S. Catarino ◽  
F.P. Castro ◽  
J. Brazão ◽  
L. Moreira ◽  
L. Pereira ◽  
...  
Keyword(s):  
Special Interest ◽  
Analytical Procedure ◽  
Isotopic Ratio ◽  
Isotopic Ratios ◽  
Grape Variety ◽  
Icp Ms ◽  
Wine Composition ◽  
Current Context ◽  
Vineyard Soils ◽  
Other World

The assessment of wine authenticity is of utmost importance in the current context of a growing market globalization. The strontium isotopic ratio 87Sr/86Sr is a well-established tool for dating and tracing the origin of rocks and minerals with special interest for wine traceability. A study was developed to examine the variation of 87Sr/86Sr in wines from Douro Valley taking into account the effects of vineyard location and grape variety. The 87Sr/86Sr of soils and wines from six vineyards were determined by using an ICP-MS based analytical procedure. A total of twenty-two monovarietal wines, obtained at micro vinification scale, from relevant white and red grapevine varieties for Douro region, were analysed. The range of 87Sr/86Sr values observed in soils and wines was of 0.708–0.725 and 0.711–0.717, respectively. The present study updates the scarce knowledge available on strontium isotopic ratios in soils and wines from Douro Valley, and its results will enlarge global databank on wine composition and support comparison with other world regions.

Improved in situ Li isotopic ratio analysis of silicates by optimizing signal intensity, isotopic ratio stability and intensity matching using ns-LA-MC-ICP-MS

2017 ◽  
Vol 32 (4) ◽  
pp. 834-842 ◽  
Author(s):  
Jie Lin ◽  
Yongsheng Liu ◽  
Xirun Tong ◽  
Lvyun Zhu ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Isotopic Ratio ◽  
Silicate Glasses ◽  
Isotopic Ratios ◽  
Ratio Analysis ◽  
Icp Ms

How to get accurate and precise in situ Li isotopic ratios of silicate glasses on a ns-LA-MC-ICP-MS (Neptune Plus).

scholarly journals Pervasive detachment faults within the slow spreading oceanic crust at the poorly coupled Antilles subduction zone

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Boris Marcaillou ◽  
Frauke Klingelhoefer ◽  
Muriel Laurencin ◽  
Jean-Frédéric Lebrun ◽  
Mireille Laigle ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Oceanic Crust ◽  
Bathymetric Data ◽  
Detachment Faults ◽  
Spreading Ridges ◽  
Basement Rocks ◽  
Mid Atlantic Ridge ◽  
Slow Spreading ◽  
Deep Fluid ◽  
Shear Planes

AbstractOceanic crust formed at slow-spreading ridges is currently subducted in only a few places on Earth and the tectonic and seismogenic imprint of the slow-spreading process is poorly understood. Here we present seismic and bathymetric data from the Northeastern Lesser Antilles Subduction Zone where thick sediments enable seismic imaging to greater depths than in the ocean basins. This dataset highlights a pervasive tectonic fabric characterized by closely spaced sequences of convex-up Ridgeward-Dipping Reflectors, which extend down to about 15 km depth with a 15-to-40° angle. We interpret these reflectors as discrete shear planes formed during the early stages of exhumation of magma-poor mantle rocks at an inside corner of a Mid-Atlantic Ridge fracture zone. Closer to the trench, plate bending could have reactivated this tectonic fabric and enabled deep fluid circulation and serpentinization of the basement rocks. This weak serpentinized basement likely explains the very low interplate seismic activity associated with the Barbuda-Anegada margin segment above.

Extremely asymmetric magmatic accretion of oceanic crust at the ends of slow-spreading ridge segments

Geology ◽  
2000 ◽  
Vol 28 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Simon Allerton ◽  
Javier Escartín ◽  
Roger C. Searle
Keyword(s):  
Oceanic Crust ◽  
Spreading Ridge ◽  
Slow Spreading

Covellite of the Semenov-2 hydrothermal field (13°31.13′ N, Mid-Atlantic Ridge): Enrichment in trace elements according to LA ICP MS analysis

2017 ◽  
Vol 473 (1) ◽  
pp. 291-295 ◽  
Author(s):  
I. Yu. Melekestseva ◽  
V. V. Maslennikov ◽  
S. P. Maslennikova ◽  
L. V. Danyushevsky ◽  
R. Large
Keyword(s):  
Trace Elements ◽  
Hydrothermal Field ◽  
Ms Analysis ◽  
Icp Ms ◽  
Mid Atlantic Ridge
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