Mafic alkaline metasomatism in the lithosphere underneath East Serbia: evidence from the study of xenoliths and the host alkali basalts

Effects of mafic alkaline metasomatism have been investigated by a combined study of the East Serbian mantle xenoliths and their host alkaline rocks. Fertile xenoliths and tiny mineral assemblages found in depleted xenoliths have been investigated. Fertile lithologies are represented by clinopyroxene (cpx)-rich lherzolite and spinel (sp)-rich olivine websterite containing Ti–Al-rich Cr-augite, Fe-rich olivine, Fe–Al-rich orthopyroxene and Al-rich spinel. Depleted xenoliths, which are the predominant lithology in the suite of East Serbian xenoliths, are harzburgite, cpx-poor lherzolite and rare Mg-rich dunite. They contain small-scale assemblages occurring as pocket-like, symplectitic or irregular, deformation-assisted accumulations of metasomatic phases, generally composed of Ti–Al- and incompatible element-rich Cr-diopside, Cr–Fe–Ti-rich spinel, altered glass, olivine, apatite, ilmenite, carbonate, feldspar, and a high-TiO2 (c. 11 wt%) phlogopite. The fertile xenoliths are too rich in Al, Ca and Fe to simply represent undepleted mantle. By contrast, their composition can be reproduced by the addition of 5–20 wt% of a basanitic melt to refractory mantle. However, textural relationships found in tiny mineral assemblages inside depleted xenoliths imply the following reaction: opx+sp1 (primary mantle Cr-spinel) ±phlogopite+Si-poor alkaline melt=Ti–Al-cpx+sp2 (metasomatic Ti-rich spinel)±ol±other minor phases. Inversion modelling, performed on the least contaminated and most isotopically uniform host basanites (87Sr/86Sr=c. 0.7031; 143Nd/144Nd=c. 0.5129), implies a source that was enriched in highly and moderately incompatible elements (c. 35–40× chondrite for U–Th–Nb–Ta, 2× chondrite for heavy rare earth elements (HREE), made up of clinopyroxene, carbonate (c. 5%), and traces of ilmenite (c. 1%) and apatite (c. 0.05%). A schematic model involves: first, percolation of CO2- and H2O-rich fluids and precipitation of metasomatic hydrous minerals; and, second, the subsequent breakdown of these hydrous minerals due to the further uplift of hot asthenospheric mantle. This model links intraplate alkaline magmatism to lithospheric mantle sources enriched by sublithospheric melts at some time in the past

Meliorism and excess aesthetics

Meliorist pragmatism (or perfectionistic pragmatism), defended by Richard Shusterman, is a view in which ethical and political dimensions are intertwined with epistemological dimensions (Mathias Girel). Experience, the main issue in Shusterman’s aesthetics, which is focused on the body, is of great importance in the aesthetics of the digital era as well. The body has become significant again not just as a subject that affects our experience, but also as a subject-object that is particularly important when it comes to receiving messages from various digital forms and popular programs such as film, video games, selfies, social media etc. In this paper, the author begins with the thesis that the aesthetics of the digital era amounts to the aesthetics of excess (Gilles Lipovetsky), which is superficial and based on stimuli and external impressions. By considering the body indispensable from the aesthetic experience, and accepting the thesis of meliorism, it seems that the aesthetics of excess could be socially desirable, especially if we invoke Shusterman’s third argument for the aesthetics of popular culture, according to which entertainment plays a positive role in human life. However, in this paper it is argued that the above-mentioned aesthetic theory faces some other problems related with loneliness, emptiness, and passivity

ETHICS OF NEWSPAPER PHOTOGRAPHY

Newspaper photographs, visual text that speaks more powerfully than written text, have been unfairly neglected in theory and practice by media scholars and professionals. The author’s starting point is the assumption that the image itself is a powerful medium in which people openly and naively believe under the slogan ‘a picture is worth a thousand words’. Its role in Serbian printed media is regulated by the decrees of the Journalism Code of Ethics in Serbia. Although the instructions are clear, they have been routinely violated in practice. The modern, digital age has brought the opportunity for photographs to be easily downloaded from the internet, while the programs for image manipulation have become more powerful, more accessible and easier to use. These opportunities represent a threat to the status that news, documentary photography has. The ethics of news photography is particularly important because the visual elements represent something the audience notices first and are therefore crucial for whether and how the written word is going to be adopted. Therefore, the participant of the study is the ethics of photography in print media in Serbia. In the analysis of three daily newspapers (Politika, Blic, Kurir), from May 12 to 14, 2014, without add-ons and program guides, the semiotic method was used, as well as the method of quantitative and qualitative analysis of all the published photographs, except advertising. The authors evaluated the ethics of photography in comparison to the Journalism Code of Ethics in Serbia. The aim was to determine to what extent there is a violation of any of the decrees relating photography. The hypotheses on which the study is based on: ethical violations can be found in all the papers, mostly in the tabloids, the least in the serious press. The most common violations are failing to emphasize the nature or the author of the illustrative photograph. There are more serious violations such as disrespect for the presumption of innocence and the right to privacy. Nonetheless, there are more ethical violations on the front page than within the newspaper.Key words:   Newspaper photograph/photography, print media, manipulation, ethics, The Journalist's Code of Serbia

The origin of volcanic section of the Vardar ophiolitic zone: a comparative petrological and geochemical study of latecretaceous volcanics from Macedonia with their jurasic counterparts from Balkans

Since the first appearance of the term “ophiolite” in 1813, its definition and interpretation was under consistent debate. First interpretation of ophiolites as being serpentinized peridotites associated with a suite of magmatic rocks evolved exclusively at the ocean floor extruded at mid ocean ridges (MOR)(e.g. Gass, 1968; Moores and Vine, 1971), was later doubted by Miyashiro (1973). Based on geochemical studies of the Troodos ophiolite (Cyprus), it was recognized close spatial and temporal occurrence of MOR-basalts with magmatic rocks typically showing subduction related calc-alkaline trend. Since then the evidence for an arc related origin of many Mediterranean ophiolites has hardened over decades, but the contrasting volcanic association of arc-lavas like boninites, arc tholeiites or adakites with MORBs was representing a long lasting conundrum. It was only recently recognized that this perplexing issue my be solved if the ophiolites formed during initiation of subduction within or near a ridge (Barth et al., 2008, Barth and Gluhak, 2009; Reagan et al., 2010; Pearce & Robinson, 2011, Božović et al., 2013). In the recent decades worldwide studies of ancient and recent ophiolites and improvement of geochemical measurement techniques led to the idea of a broad geotectonic range of ophiolite generation (Dilek and Furnes, 2011). Although the magmatic origin of ophiolites in an ocean extension environment is unquestioned, Dilek and Furnes (2011) further subdivided ophiolites in supra-subduction zone, continental margin, mid-ocean-ridge, plume-type, volcanic arc and accretionary-type ophiolites

En intervjustudie om några elevers upplevelser om den feedback som de får från sina lärare

Formativ bedömning eller bedömning för lärande introducerades i en kommun i södra Sverige 2013. Målsättningen har sedan dess varit att få med alla yrkesverksamma pedagoger i kommunen till att arbeta formativt i sina klassrum. Bedömning för lärande består av sex nyckelstrategier där feedback, som för lärandet framåt, är en av dessa. Feedback kan ges på olika sätt men de mest vanliga är skriftlig feedback och muntlig feedback. Få studier har gjorts där man har varit intresserad av elevers upplevelser av det formativa arbetssättet. Syftet med denna studie har varit att komma åt elevernas upplevelser av feedback. Vilken sorts feedback föredrar eleverna? När upplever eleverna feedback som betydelsefull? Och finns det faktorer som påverkar mottagandet av feedback? För att svara på dessa frågor har sex elever i årskurs nio intervjuats. Dessa elever har alla gått i en kommunal skola och under många år fått feedback, både muntligt och i skrift. Det insamlade materialet från intervjuerna har sedan kategoriserats och analyserats med hjälp av den sociokulturella teorin och det formativa förhållningssättet. Både dessa utgår ifrån att, samarbetsinriktade aktiviteter mellan lärare och elever, är viktiga förutsättningar för elevens lärande. Resultatet visar att det, enligt eleverna, finns för- och nackdelar med både muntlig och skriftlig feedback. Det eleverna värdesätter mest är feedbackens utformning, även om relationen med läraren också kan vara av betydelse. Eleverna anser att feedback bör bekräfta prestationen för att därefter föreslå förändringar som behöver göras. Detta för att eleverna ska känna sig motiverade till att fortsätta arbeta med uppgiften och ämnet.Formative assessment was introduced in a municipality in the south of Sweden year 2013.Since then the aim of the initiative has been to inspire all teachers to apply a formativeassessment in the classrooms. Formative assessment includes five key strategies wherefeedback is one of them. Feedback could be presented in various ways but the mostcommon one is written and spoken feedback received on a task. Not many studies aremade on the students’ experiences of formative assessment. Therefore, the purpose ofthis study is to widen the understanding of the students’ experiences, what kind offeedback they prefer, when they appreciate the feedback as an important scaffolding andif there are contributing factors to their overall experience of feedback. To answer thesequestions, interviews were made with six students in the Swedish secondary school.They have all attended a public school in a municipality during many years and receivedfeedback both written and spoken. The information from the interviews has beencategorized and analyzed through a sociocultural theory. This theory argues thatcooperation between student and teacher is necessary for the development of thestudent. According to the students, there are pros and cons to both written and spokenfeedback. Students mostly value the shape of the feedback, but the relationship betweenstudent and teacher can also matter when feedback is given. The students believe thatfeedback should acknowledge the effort as well as suggest further development for thestudents to feel motivated to continue the work, both with the assignment and thesubject in general