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The Late Cretaceous Klepa basalts in Macedonia (FYROM)—Constraints on the final stage of Tethys closure in the Balkans 
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下载免费PDF全文 Dejan Prelević Simon Wehrheim Magnus Reutter Rolf L. Romer Blažo Boev Milica Božović Paul van den Bogaard Vladica Cvetković Stefan M. Schmid 《地学学报》2017,29(3):145-153
The waning stage(s) of the Tethyan ocean(s) in the Balkans are not well understood. Controversy centres on the origin and life‐span of the Cretaceous Sava Zone, which is allegedly a remnant of the last oceanic domain in the Balkan Peninsula, defining the youngest suture between Eurasia‐ and Adria‐derived plates. In order to investigate to what extent Late‐Cretaceous volcanism within the Sava Zone is consistent with this model we present new age data together with trace‐element and Sr–Nd–Pb isotope data for the Klepa basaltic lavas from the central Balkan Peninsula. Our new geochemical data show marked differences between the Cretaceous Klepa basalts (Sava Zone) and the rocks of other volcanic sequences from the Jurassic ophiolites of the Balkans. The Klepa basalts mostly have Sr–Nd–Pb isotopic and trace‐element signatures that resemble enriched within‐plate basalts substantially different from Jurassic ophiolite basalts with MORB, BAB and IAV affinities. Trace‐element modelling of the Klepa rocks indicates 2%–20% polybaric melting of a relatively homogeneously metasomatised mantle source that ranges in composition from garnet lherzolite to ilmenite+apatite bearing spinel–amphibole lherzolite. Thus, the residual mineralogy is characteristic of a continental rather than oceanic lithospheric mantle source, suggesting an intracontinental within‐plate origin for the Klepa basalts. Two alternative geodynamic models are internally consistent with our new findings: (1) if the Sava Zone represents remnants of the youngest Neotethyan Ocean, magmatism along this zone would be situated within the forearc region and triggered by ridge subduction; (2) if the Sava Zone delimits a diffuse tectonic boundary between Adria and Europe which had already collided in the Late Jurassic, the Klepa basalts together with a number of other magmatic centres represent volcanism related to transtensional tectonics. 相似文献
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<正>This study used trace elements in olivine as a new petrogenetic indicator to further constrain the petrogenesis of potassic basalts from the Erkeshan-Wudalianchi-KeluoXiaogulihe potassic volcanic field(EWKX for short)in the Songliao Basin of NE China,with a combination of the previous olivine and whole-rock geochemical data.We 相似文献
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Dejan Vasović Srđan Kostić Marina Ravilić Slobodan Trajković 《Environmental Earth Sciences》2014,72(10):3915-3928
In present paper, the blast-induced ground motion and its effect on the neighboring structures are analyzed at the limestone quarry "Drenovac" in central part of Serbia. Ground motion is examined by means of existing conventional predictors, with scaled distance as a main influential parameter, which gave satisfying prediction accuracy (R > 0.8), except in the case of Ambraseys–Hendron predictor. In the next step of the analysis, a feed-forward three-layer back-propagation neural network is developed, with three input units (total charge, maximum charge per delay and distance from explosive charge to monitoring point) and only one output unit (peak particle velocity). The network is tested for the cases with different number of hidden nodes. The obtained results indicate that the model with six hidden nodes gives reasonable predictive precision (R ≈ 0.9), but with much lower values of mean-squared error in comparison to conventional predictors. In order to predict the influence level to the neighboring buildings, recorded peak particle velocities and frequency values were evaluated according to United States Bureau of Mines, USSR standard, German DIN4150, Australian standard, Indian DMGS circular 7 and Chinese safety regulations for blasting. Using the best conventional predictor, the relationship between the allowable amount of explosive and distance from explosive charge is determined for every vibration standard. Furthermore, the effect of air-blast overpressure is analyzed according to domestic regulations, with construction of a blasting chart for the permissible amount of explosive as a function of distance, for the allowable value of air-blast overpressure (200 Pa). The performed analysis indicates only small number of recordings above the upper allowable limit according to DIN4150 and DMGS standard, while, for all other vibration codes the registered values of ground velocity are within the permissible limits. As for the air-blast overpressure, no damage is expected to occur. 相似文献
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Aleksandar Milosavljević Dejan Rančić Aleksandar Dimitrijević Bratislav Predić Vladan Mihajlović 《International journal of geographical information science》2016,30(10):2089-2107
This paper discusses the integration of three-dimensional (3D) geographic information systems (GIS) and video surveillance systems using augmented reality (AR) techniques. The motivation for this integration is to overcome problems faced by conventional video surveillance systems. Explicit information concerning which camera currently monitors what area in such systems is missing; therefore, insight into the situation depends heavily on the operator’s training and experience. To ensure the complete coordination and monitoring of a situation in a system with multiple cameras, it is necessary to introduce a single reference system. GIS arises as a natural solution because it not only provides a solid ground truth but also provides semantic information that can be highly important in certain video surveillance applications. To integrate information into a GIS application, that information must be georeferenced. Based on our previous research regarding the addition of georeferencing information to surveillance video, this paper introduces models that can be applied to help integrate video and GIS. With an analogy to Milgram’s continuum between the real world and virtual reality, and analogous to the augmented reality and augmented virtuality in Milgram’s continuum, two models of integration are defined here: GIS-augmented video and video-augmented GIS. Then, we define the architecture of GIS-based video surveillance based on these proposed integration models, and finally, a prototype is implemented. The implemented prototype serves as a basis for analysing possible applications of real-world systems based on the integration of GIS and video. 相似文献
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The aim of this paper is to present an application of robust inverse Nyquist array control design method to a milling circuit in Majdanpek Copper Mine. An existent model of a milling circuit was adopted to respond to robust inverse Nyquist array methodology demand by introducing model uncertainty, and optimal robust controller of milling circuit is designed. The proposed controller is robust for reference signals. The robustness of multivariable feedback systems with designed controller is tested and compared with different, previously designed multivariable controllers. Simulation results, in time domain, demonstrate the preferable performance of the designed robust controller in setpoint tracking. Implementation of the new controller without any investments in new equipment significantly improves performance of the milling process. 相似文献
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Orthopyroxene-rich olivine websterite xenoliths (OWB2) in Palaeogene basanites in East Serbia are mostly composed of tabular low-Al2O3 orthopyroxene (> 70 vol.%, Mg# 85–87) containing tiny Cr spinel inclusions. Orthopyroxene shows a slightly U-shaped primitive mantle-normalized trace element pattern with strong peaks at U and Pb, similar to that of orthopyroxene from normal regional peridotitic mantle. In between the orthopyroxenes are interstitial spaces composed of partially altered olivine (Mg# 85–87), clinopyroxene, Ti-rich spinel, Mg-bearing calcite, K-feldspar, apatite, ilmenite and relicts of a hydrous mineral. Clinopyroxene appears as selvages around orthopyroxene and as coarser euhedral crystals. Trace element patterns of the clinopyroxene selvages resemble those of adjacent orthopyroxene, whereas the coarser ones have flatter and more LREE- and LILE-enriched patterns, similar to that of metasomatic clinopyroxene. The OWB2 xenoliths are interpreted as having formed in two stages. During Stage I orthopyroxene crystallized, along with some spinel, olivine and probably hydrous phase(s). This original OWB2 lithology was a hydrous olivine-bearing orthopyroxenite that crystallised from subduction-related SiO2-saturated, boninite-like magmas. During Stage II the interstitial minerals formed due to infiltration of a low-SiO2, high-CaO and CO2-rich external melt, accompanied by decomposition of original H2O-bearing minerals. The calculated composition of the infiltrating liquid corresponds to a mafic alkaline melt similar to the basanitic host but more enriched in CO2, LREE and LILE. Metasomatism is interpreted in terms of small degree melts related to the Palaeogene mafic alkaline magmatism. 相似文献
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橄榄石微量元素原位分析的现状及其应用 总被引：4，自引：1，他引：3
随着高精度EMPA和LA-ICP-MS分析技术的发展和矿物微量元素测试精度的提高,利用橄榄石中的微量元素示踪地幔部分熔融、地幔交代作用、岩浆早期结晶过程等地质问题成为近年来一个新兴的研究方向。一系列开拓性的研究发现也被陆续的发表,主要涉及橄榄石中Ni、Co、Al、Cr、Zn、Ti、Li、V、Sc、Mn、Ca和P等元素的示踪使用。一些卓有成效的示踪方法为:Ca、Al、Ti、Ni及Mn能够很好的用于区分橄榄石捕掳晶和斑晶;橄榄石-尖晶石地幔演化趋势线(OSMA:olivine-spinel mantle array)图解可以用于表征岩浆源区的亏损程度;玄武岩中橄榄石斑晶的Li同位素及Li含量可以很有效地指示岩浆源区是否存在地壳物质再循环及地幔交代作用;橄榄石斑晶中Ni、Ca、Mn、Cr和Al协变关系图解可以识别岩浆的辉石岩源区;利用橄榄石捕掳晶中Zr和Sc的含量差异特征可将橄榄岩中三种最主要的类型(尖晶石橄榄岩、石榴石橄榄岩以及尖晶石-石榴石橄榄岩)区分开来;一些元素的比值或组合(例如Ni/Co、Fe/Mn、V/Sc、Zr和Sc、Ca和Ti)可以指示源区交代作用、岩浆作用过程及氧化状态;基于橄榄石中Al、Cr及Ca的地质温度计可以为推算地幔热状态提供新方法;基于橄榄石分离结晶Fo-NiO演化线的原始岩浆计算模型可以较好的推算原始岩浆成分;利用橄榄石的环带及微量元素的扩散机制可以判别更多岩石成因信息,如识别交代介质、熔体类型以及地质构造背景等。基于上述最新研究的相关资料和已有成果,本文对橄榄石微量元素的地球化学示踪方法做系统性的归纳整理,并对橄榄石微量元素赋存状况、橄榄石微量元素测试方法、橄榄石微量元素的使用条件及需注意的问题等进行讨论,为读者在做相关研究时提供参考。 相似文献
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Cüneyt Akal Osman Candan O. Ersin Koralay Roland Oberhänsli Fukun Chen Dejan Prelević 《International Journal of Earth Sciences》2012,101(1):177-194
Afyon Zone, which was derived from the Anatolide–Tauride platform during closure of the Neo-Tethys, is made up of pre-Mesozoic
basement and unconformably overlying Triassic–Early Tertiary cover series. The Afyon Zone contains widespread metavolcanic
rocks, which are dominated by rhyolite, dacite, and trachyandesite. They form a distinct volcanic succession, which is separated
from the underlying Silurian–Lower Carboniferous metacarbonates and meta-siliciclastics by a regional unconformity. Trachyandesitic
metavolcanics are made up of massive lava flows, pyroclastics and epiclastics, less frequently, domes and dikes, which were
developed on a deeply eroded subaerial landmass. U/Pb and Pb/Pb zircon geochronology yielded Lower Triassic (~250 Ma) ages,
which are interpreted as extrusion age of trachyandesitic volcanics. Based on the stratigraphic, geochronological, and geochemical
data, we suggest that these Lower Triassic magmatic rocks represent an extensional tectonic setting on the northern active
margin of the Gondwana, which led to the development of the northern branch of the Neo-Tethys. 相似文献
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Dejan Pavlic 《Urban geography》2013,34(3):378-401
Spatially referenced quantitative research that attempts systematically to assess inner suburban decline in Canadian metropolitan areas is almost completely missing from the literature. This paper aims to fill this gap and examine whether inner suburban decline is occurring in Canada. Aggregated census tract level data are used to assess all zones for decline based on relative prosperity changes in median household income, average dwelling values, and average gross rent. The results indicate that inner suburbs in Canadian cities experienced a decline in median household income, average dwelling value, and prosperity factors between 1986 and 2006. While a few possible explanations and policy approaches are offered, more research is necessary to explore the implications of these trends. 相似文献