Journal of Geosciences最新文献_第9页

Petrogenesis of fractionated nested granite intrusions: the Sedmihoří Composite Stock (Bohemian Massif) 分级嵌套花岗岩侵入体的岩石成因：Sedmihoří复合岩群（波西米亚地块）

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2020-02-12 DOI: 10.3190/jgeosci.294

J. Trubač, V. Janoušek, A. Gerdes

引用次数: 2

Stratigraphy, structure and geology of Late Miocene Verkhneavachinskaya caldera with basaltic-andesitic ignimbrites at Eastern Kamchatka 堪察加半岛东部晚中新世Verkhneavachinskaya破火山口的地层、结构和地质特征

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2020-02-12 DOI: 10.3190/jgeosci.295

O. Bergal-Kuvikas, V. Leonov, A. Rogozin, I. Bindeman, Evgeniy Kliapitskiy, T. Churikova

引用次数: 4

Radiogenic heat production of Variscan granites from the Western Bohemian Massif, Germany 来自德国西波西米亚地块的瓦里斯坎花岗岩的放射成因热生产

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2020-02-12 DOI: 10.3190/jgeosci.293

L. Scharfenberg, Anette Regelous, H. Wall

{"title":"Radiogenic heat production of Variscan granites from the Western Bohemian Massif, Germany","authors":"L. Scharfenberg, Anette Regelous, H. Wall","doi":"10.3190/jgeosci.293","DOIUrl":"https://doi.org/10.3190/jgeosci.293","url":null,"abstract":"Much of the Mid-European basement has been consolidated during the Variscan Orogeny and includes large volumes of granitic intrusions. Gamma radiation spectroscopic measurements in three study areas along the western margin of the Bohemian Massif give a record of radiogenic element concentrations in the Variscan granites. Most intrusions of the Fichtelgebirge (except for the Tin Granite) and intrusive complexes in the Bavarian Forest show Th/U ratios exceeding unity, most likely related to abundance of monazite. In contrast, some of the Oberpfalz granites located near the Saxothuringian–Moldanubian boundary (Flossenbürg, Steinwald and Friedenfels types) are characterized by higher uranium concentrations and thus Th/U < 1. The low Th/U ratios here are in agreement with a possible U mobilisation along the Saxothuringian–Moldanubian contact zone observed in previous studies. Heat production rates of granites in the three study areas vary between 3.9 and 8.9 µW/m 3 , with a mean of 4.9 µW/m 3 . This classifies the intrusions as moderate- to high-heat-producing granites. Considering the huge volume of granitic bodies in the Variscan crust of the Bohemian Massif, the contribution of in situ radiogenic heat production had to have a major impact and should be considered in further thermal modeling. contains on the surface heat flow. Hasterok and Chapman (2011) estimated that 26 % of the surface heat flow is generated by the upper continental crust. The new database GRAN-ITE2017 has been set up to compile available data on worldwide granitic terrains of all ages (Artemieva al. Based on statistical analysis, first conclusions have been made on variation of bulk heat production of granites through geological time. These results show a peak in the Middle Proterozoic times and a gradual decrease towards younger (Cenozoic) intrusions.","PeriodicalId":15957,"journal":{"name":"Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43173284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Anorogenic Early Permian dykes in the western Mongolian Altai - petrography, geochemistry and K-Ar geochronology 蒙古阿尔泰西部早二叠世造山岩脉——岩石学、地球化学和钾氩年代学

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.280

V. Žáček, D. Buriánek, Z. Pécskay, R. Škoda

{"title":"Anorogenic Early Permian dykes in the western Mongolian Altai - petrography, geochemistry and K-Ar geochronology","authors":"V. Žáček, D. Buriánek, Z. Pécskay, R. Škoda","doi":"10.3190/JGEOSCI.280","DOIUrl":"https://doi.org/10.3190/JGEOSCI.280","url":null,"abstract":"A variety of felsic and mafic dykes grouped into swarms intruded the Lower Palaeozoic volcano-sedimentary sequences (flysch) and Late Devonian to Early Carboniferous plutonic rocks in the Hovd and Altai zones of the Central Asian Orogenic Belt (CAOB), western Mongolian Altai. The dykes reach a thickness of 0.5–20 m, length of approximately 50–2,500 m and strike mostly SW–NE or E–W. The felsic rocks chemically correspond to high-K calc-alkaline to alkaline rhyolites. Compositional trends of mafic rocks pass from alkalineand calc-alkaline basalts to trachyandesite. The bimodal nature of the association and the transitional calc-alkaline to alkaline character of the dykes indicate magma production through partial melting of the mantle and continental crust in an intra-plate (rift) geodynamic setting. The new conventional whole-rock K–Ar dating of mafic and felsic dykes yielded ages ranging from 300 ± 9 to 281 ± 9 Ma (1σ). This indicates anorogenic volcanic activity associated with Late Carboniferous to Early Permian extension coeval with magmatism in the Gobi–Altai Rift and in the adjacent parts of the Chinese Altai. The calculated crystallization pressures of 1–2 kbar and 0.3–0.4 kbar for felsic and mafic rocks, respectively, indicate emplacement at shallow levels.","PeriodicalId":15957,"journal":{"name":"Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42062131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Giftgrubeite, CaMn2Ca2(AsO4)2(AsO3OH)2·4H2O, a new member of the hureaulite group from Sainte-Marie-aux-Mines, Haut-Rhin Department, Vosges, France Giftgrubeite，CaMn2Ca2（AsO4）2（AsO3OH）2·4H2O，来自法国Vosges上莱茵省Sainte-Marie aux矿山的hureaulite集团的新成员

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.276

N. Meisser, J. Plášil, Thierry Brunsperger, C. Lheur, R. Škoda

引用次数: 2

Zalužany - a circular structure in the Czech Republic accompanied by glass of granodiorite composition Zalužany -捷克共和国的一个圆形结构，伴随着花岗闪长岩组成的玻璃

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.281

S. Vrána, J. Mrlina, R. Škoda, P. Halodová

{"title":"Zalužany - a circular structure in the Czech Republic accompanied by glass of granodiorite composition","authors":"S. Vrána, J. Mrlina, R. Škoda, P. Halodová","doi":"10.3190/JGEOSCI.281","DOIUrl":"https://doi.org/10.3190/JGEOSCI.281","url":null,"abstract":"The Hejný Pond, 500 × 400 m, southeast of the Zalužany village in central Bohemia, attracted attention as a possible impact structure. The pond has a notable bilateral symmetry with an axis oriented NW–SE, indicating a significant subhorizontal vector in the overall deformation pattern. A negative gravity anomaly elongated in the same direction (600 × 300 m) with the amplitude of –0.35 mGal was disclosed by detailed gravity survey. The incomplete ring of elevations suggests slightly uplifted basement segments with a diameter of 1 km. Search for glass and other possible indicators of shock metamorphism resulted in a find of glass fragments 22 to 37 mm across. The glass has composition comparable to the local Kozárovice hornblende–biotite granodiorite of the Central Bohemian Plutonic Complex. Unusual features include locally high contamination by iron (up to 10–13 wt. % FeOt) and abundant cristobalite. The absence of planar deformation features in quartz and feldspars together with the absence of platinum-group elements and Ni enrichment in local glass may be considered as obstacles in defining Zalužany as an impact structure. Although glass fragments are rare at the locality, and the considerable Quaternary erosion, the occurrence of rock inclusions in two of the fragments makes the Zalužany structure a promising object for future study.","PeriodicalId":15957,"journal":{"name":"Journal of Geosciences","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41937284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Octahedral substitution in beryl from weakly fractionated intragranitic pegmatite Predné Solisko, Tatry Mountains (Slovakia): the indicator of genetic conditions Tatry Mountains（斯洛伐克）PrednéSolisko弱分级花岗伟晶岩绿柱石的八面体取代：遗传条件的指标

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.272

P. Bačík, Jana Fridrichová, P. Uher, S. Rybár, V. Bizovská, J. Luptáková, Dana Vrablíková, L. Pukančík, T. Vaculovič

引用次数: 5

Trace-element chemistry of barren and ore-bearing quartz of selected Au, Au-Ag and Sb-Au deposits from the Bohemian Massif 波西米亚地块部分Au、Au- ag和Sb-Au矿床贫矿石英微量元素化学特征

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.279

K. Pacak, J. Zachariáš, L. Strnad

{"title":"Trace-element chemistry of barren and ore-bearing quartz of selected Au, Au-Ag and Sb-Au deposits from the Bohemian Massif","authors":"K. Pacak, J. Zachariáš, L. Strnad","doi":"10.3190/JGEOSCI.279","DOIUrl":"https://doi.org/10.3190/JGEOSCI.279","url":null,"abstract":"The trace-element contents in gold-bearing and barren quartz veins from eight Au, Au–Ag and Sb–Au Variscan deposits in the Bohemian Massif have been determined in situ in order to evaluate the differences between the various types of gold deposits and discuss trace-element variations in the successive generations of quartz veins. The variability of Ti, Al, Ge, Li and Sb abundances obtained by Laser-Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS) roughly correlates with the origin and the temperature of the mineralizing fluids. The Al content ranges up to 4020 ppm (median value 230 ppm), while the Li content is generally low (< 4 ppm). The elevated Sb content (30–360 ppm Sb) is only related to quartz that immediately preceded deposition of Sb-rich phases. The titanium content of the ore-bearing vein quartz follows bimodal distribution: gold deposits with assumed higher temperature (> 450 °C) formation exhibit higher median values (~10 ppm Ti) than medium-to-low (< 300 °C) temperature deposits (~2 ppm Ti). A statistically significant threshold value (8 ppm Ti) has been recognized as an empirical tool for discriminating between them. In terms of the Ti and Al contents, the studied Bohemian gold deposits fall within and in between fields of orogenic gold and porphyry deposit types.","PeriodicalId":15957,"journal":{"name":"Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47906122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

An open access-journal with a difference 具有差异的开放存取日记账

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-12-05 DOI: 10.3190/JGEOSCI.282

V. Janoušek

引用次数: 0

Gladkovskyite, MnTlAs3S6, a new thallium sulfosalt from the Vorontsovskoe gold deposit, Northern Urals, Russia 俄罗斯北乌拉尔Vorontsovskoe金矿新发现的铊硫盐

IF 1.4 4区地球科学

Journal of Geosciences Pub Date : 2019-11-16 DOI: 10.3190/jgeosci.290

A. Kasatkin, E. Makovicky, J. Plášil, R. Škoda, N. Chukanov, Sergey Y. Stepanov, A. Agakhanov, F. Nestola

引用次数: 12