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Central European Geology
Authors: Zsófia Pálos, István János Kovács, Dávid Karátson, Tamás Biró, Judit Sándorné Kovács, Éva Bertalan, Anikó Besnyi, György Falus, Tamás Fancsik, Martina Tribus, László Előd Aradi, Csaba Szabó and Viktor Wesztergom

.%) “wet” “dry” “wet” “dry” 1 Nagy-Hideg-hegy Lava flow Normal non-rotated 5

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G. Kniewald 2008 Volcanic facies analysis of a subaqueous basalt lava-flow complex at Hruškovec, NW Croatia — evidence of advanced rifting in the Tethyan domain J. Volc. and

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Abstract  

The western region of the Deccan Volcanic Province (DVP) is constituted of tholeiitic lava flows. They host numerous cavities, varying in size and shape, largely occupied by zeolites and a variety of secondary minerals, amongst which the fibrous zeolites (natrolite group), are particularly gorgeous and attractive. Scolecite and mesolite are the only two members commonly occurring in this region. Our data on their thermal behaviour significantly differs from that reported in previous literature. Scolecite, Ca8(Al16Si24O80)·24H2O shows three distinct steps instead of two and water loss is observed even beyond 550°C. It is held that the first step corresponds to the expulsion of water from the site farthest away from Ca and the next two steps in succession correspond to the two sites nearer to Ca. Mesolite, Na16Ca16(Al48Si72O240)· 64H2O has much more complex behaviour with four or five steps of water expulsion and a major loss around 248–270°C in a double reaction attributed here to the expulsion of water from scolecite type channels. It is further held that the natrolite type channels are emptied in further steps. Loss of water in steps even beyond 400°C is particularly noted and such reactions are well reflected in the TG and the DTG. Peak temperature dependence on sample amounts is also evident. Successive phase transformations above 700°C, up to 1000°C are reflected in the DTA curves.

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Community Ecology
Authors: G. Bonanomi, G. Incerti, A. Stinca, F. Cartenì, F. Giannino and S. Mazzoleni

Ring shaped patches of clonal plants fascinated plant ecologists since long time. In this work we review the reports on the occurrence of ring pattern in different environmental conditions, the growth forms of ring-forming plants, the mechanisms underlying ring formation, and the consequences for species diversity at community scale. Rings formed by 83 species of clonal vascular plants have been found in grasslands, deserts, bare substrates of lava flow, harvested peat lands, salt marshes, and sand dunes. Four causal hypotheses have been proposed for the emergence of ring patterns: i. occurrence of architectural constraints for ramets development; ii. induction by fire, drought, trampling or overgrazing; iii. nutrient and water depletion by competition inside the ring; and iv. onset of species-specific negative plant-soil feedback in the inner zone of the clone. Since almost all the available studies are observations of ring structure or modelling exercises, none of the putative mechanisms for ring formation emerged from the literature as either generally applicable or suitable for rejection. Therefore, long-term field experiments are needed to investigate the relative prevalence of different mechanisms in different environments. Ring formation bears important consequences at community scale, because ring forming plants often act as “nurses”, enhancing the recruitment and development of different plant species. In fact, ring establishment modifies above- and below-ground environmental conditions, providing specialized safe sites for beneficiaries in the inner zone of the clones. Such interspecific facilitation by ring forming plants, particularly in chronically stressed environments, contributes to increase plant species richness and can locally promote the successional dynamics.

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flows. - Nature, 434/31, pp. 633 - 636 . Structural and temporal requirements for geomagnetic field reversal deduced from lava flows Nature 434

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Acta Geologica Hungarica
Authors: Réka Lukács, György Czuppon, Szabolcs Harangi, Csaba Szabó, Theodor Ntaflos and Friedrich Koller

Manley, C., R. 1996: Morphology and maturation of melt inclusions in quartz phenocrysts from the Badlands rhyolite lava flow, southwestern Idaho. - Am. Miner., 81, pp. 158-168. Morphology and maturation of melt inclusions in

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G. Kniewald 2008 Volcanic facies analysis of a subaqueous basalt lava-flow complex at Hruškovec, NW Croatia — evidence of advanced rifting in the Tethyan domain J. of Volc

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the samples were previously interpreted as the alternation of volatile-rich and volatile-poor bands within the presumed lava flow by Szepesházy (1967) . It is important to note that, in the ca. 60 km 2 area ( Fig. 1c ), all felsic volcanic rocks

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the samples were previously interpreted as the alternation of volatile-rich and volatile-poor bands within the presumed lava flow by Szepesházy (1967) . It is important to note that, in the ca. 60 km 2 area ( Fig. 1c ), all felsic volcanic rocks

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métamorphites, serpentinites et granitoides hercyniens. Thèse de Docteur Ingenieur. — Université Scientifique et Médicale de Grenoble, 277 pp. Majidi , B. 1981 : The ultrabasic lava flows of

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