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 ◽  
...  

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).

Intraplate volcanic lineaments include ocean island chains and continental rift systems. Basic lavas erupted in such lineaments form a continuum from tholeiitic basalt in the basements of ocean islands to nephelinites and melilitites in continental rifts and as a capping on ocean islands. All these magma types are enriched in large-ion lithophile elements (l.i.l.e.) compared with mid-ocean ridge basalts (m.o.r.b.), although isotopic data suggest that their mantle sources had been depleted in l.i.l.e. for long periods. In this paper we present a comparison of geochemical data from several suites of basic volcanic rocks ranging from Hawaiian tholeiite to Ugandan melilitite. L.i.l.e. abundance patterns can, in most cases, be explained by variable degrees of melting of a l.i.l.e.-depleted m.o.r.b. mantle source containing l.i.l.e.-rich streaks. Metasomatic enrichment of the mantle source is not a necessary precursor to magmatism.


2019 ◽  
Vol 489 (5) ◽  
pp. 483-489
Author(s):  
N. S. Bortnikov ◽  
S. А. Silantiev ◽  
F. Bea ◽  
P. Montero ◽  
T. F. Zinger ◽  
...  

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.


1987 ◽  
Vol 120 ◽  
pp. 461-467
Author(s):  
V. Vanysek

It is belived that the unprocessed material of the solar nebula may be preserved in comets. Thus the data concerning the chemical composition and the abundance of stable isotopes in these primitive bodies are of some importance in cosmological and cosmogonical context. Although the isotopic abundance in the small bodies of the Solar System are poorly known, owing to the forthcoming Halley fly-by missions, the discussion as whether or not the comets have preserved the cosmic isotopic ratio in their nuclei became more relevant. From this point of view expected data of the cosmologically and cosmogonically significant isotopic ratios of stable isotopes of the light elements in comets are discussed.


2019 ◽  
Vol 12 ◽  
pp. 02031
Author(s):  
S. Catarino ◽  
F.P. Castro ◽  
J. Brazão ◽  
L. Moreira ◽  
L. Pereira ◽  
...  

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.


Author(s):  
Richard A. Batchelor

ABSTRACTA number of approaches to interpreting geochemical data for categorising and correlating metabentonites are presented. Bulk rock geochemistry, combined with data from cognate minerals, provides the most robust means of characterising an altered ash bed. While it is not possible at present to identify one single parameter which can uniquely fingerprint an altered ash bed, it is possible to come close to an unique fingerprint, or ‘Golden Spike’, by utilising an array of geochemical parameters comprising bulk rock element ratios, Rare Earth Elements, Sr and Nd isotopic ratios in apatite, composition of sandine phenocrysts, and the chemical composition of melt inclusions.


2017 ◽  
Vol 32 (4) ◽  
pp. 834-842 ◽  
Author(s):  
Jie Lin ◽  
Yongsheng Liu ◽  
Xirun Tong ◽  
Lvyun Zhu ◽  
Wen Zhang ◽  
...  

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


Author(s):  
D. A. Petrochenkov

Fossils of marine reptiles are a new jewelry and ornamental material and collected in the Ulyanovsk region from the Upper Jurassic deposits. They consist of (wt. %): calcite — 52, apatite — 24 and pyrite — 23, and also gypsum presents. The contents of radioactive and carcinogenic elements are close to background. The original bone structure of reptiles is preserved. Apatite replaces the bone tissue of marine reptiles, forming a cellular framework. According to the chemical composition, apatite refers to fluorohydroxyapatite with an increased Sr content. The size of the crystals is finely-dispersed. Calcite and pyrite fill the central parts of the cells. Calcite crystals of isometric and elongated shape, 0,01—0,05 mm in size, form blocks up to 0,3 mm during intergrowth. Calcite fills thin, discontinuous veins along the contour of cells with a width of up to 0,03 mm. In calcite, among the impurity elements, there are (wt. %, on the average): Mg — 0,30, Mn — 0,39 and Fe — 0,96. Pyrite forms a dispersed impregnation in calcite and apatite, content of impurities is, wt. %: Ni — up to 0,96 and Cu — up to 0,24. On technological and decorative characteristics of fossils of sea reptiles of Ulyanovsk region are qualitative jewelry and ornamental materials of biomineral group, allowing to make a wide assortment of jewelry and souvenir products.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 653
Author(s):  
Nataša Imenšek ◽  
Vilma Sem ◽  
Mitja Kolar ◽  
Anton Ivančič ◽  
Janja Kristl

In view of growing requirements of the food industry regarding elderberries (genus Sambucus), a need to increase their productivity and improve their chemical composition has emerged. With this purpose in mind, numerous elderberry interspecific hybrids have been created. In the present work, the content of minerals in their crucial plant parts was studied. It was also investigated whether superior genotypes regarding the mineral composition of berries and inflorescences could be predicted at early stages of plant development. The results showed that elderberry leaves contained the highest amounts of Ca, Mg, Mn, Zn, and Sr, while K and P were predominant in fruit stalks. Fe and Al prevailed in roots and Cu in bark. Although berries showed lower mineral content compared to other plant parts, their mineral content is not negligible and could be comparable to other commonly consumed berries. Genotypes with a favorable mineral content of inflorescences and berries could be predicted on the basis of known mineral composition of their shoots and leaves. The study also indicates that S. nigra genotypes and the majority of interspecific hybrids analyzed are suitable for further genetic breeding or cultivation.


2021 ◽  
pp. 1-22
Author(s):  
Jia-Hao Jing ◽  
Hao Yang ◽  
Wen-Chun Ge ◽  
Yu Dong ◽  
Zheng Ji ◽  
...  

Abstract Late Mesozoic igneous rocks are important for deciphering the Mesozoic tectonic setting of NE China. In this paper, we present whole-rock geochemical data, zircon U–Pb ages and Lu–Hf isotope data for Early Cretaceous volcanic rocks from the Tulihe area of the northern Great Xing’an Range (GXR), with the aim of evaluating the petrogenesis and genetic relationships of these rocks, inferring crust–mantle interactions and better constraining extension-related geodynamic processes in the GXR. Zircon U–Pb ages indicate that the rhyolites and trachytic volcanic rocks formed during late Early Cretaceous time (c. 130–126 Ma). Geochemically, the highly fractionated I-type rhyolites exhibit high-K calc-alkaline, metaluminous to weakly peraluminous characteristics. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high-field-strength elements (HFSEs), with their magmatic zircons ϵHf(t) values ranging from +4.1 to +9.0. These features suggest that the rhyolites were derived from the partial melting of a dominantly juvenile, K-rich basaltic lower crust. The trachytic volcanic rocks are high-K calc-alkaline series and exhibit metaluminous characteristics. They have a wide range of zircon ϵHf(t) values (−17.8 to +12.9), indicating that these trachytic volcanic rocks originated from a dominantly lithospheric-mantle source with the involvement of asthenospheric mantle materials, and subsequently underwent extensive assimilation and fractional crystallization processes. Combining our results and the spatiotemporal migration of the late Early Cretaceous magmatic events, we propose that intense Early Cretaceous crust–mantle interaction took place within the northern GXR, and possibly the whole of NE China, and that it was related to the upwelling of asthenospheric mantle induced by rollback of the Palaeo-Pacific flat-subducting slab.


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