Search results for "Massif"
showing 10 items of 112 documents
Implicaciones del turismo masivo en un destino de cruceros
2020
[EN] One of the types of tourism that can generate greater problems of overtourism is cruise ship tourism, given the large number of people who disembark at a port of call to visit the destination. For this reason, the present study aims to analyze the perception of massification among cruise ship tourists visiting an important Mediterranean port of call and how it influences their satisfaction with their visit. To this end, using structural equation models and from a sample of cruise ship passengers, the model proposed in this study is tested. The results indicate that of the two typologies of massification analysed, it is spatial massification that contributes most to the perception of to…
Two new species of the genus emNemaspela/em Šilhavý from caves in Georgia (Opiliones: Nemastomatidae).
2021
Two highly specialized endemic troglobiotic harvestman species of the genus Nemaspela Šilhavý, 1966 are described. N. melouri sp. nov. from Melouri Cave and N. prometheus sp. nov. from Prometheus Cave (Sataplia-Tskaltubo karst massif, Imereti region, western Georgia), respectively. Despite the fact that the entrances of the caves are positioned only 2.5 km apart, the new taxa differ from each other distinctly by presence vs. absence of male cheliceral apophysis, which is lacking in the second species. A key to the Caucasian species of the genus is provided. Relationships of Nemaspela species within the genus and with hypothetical epigean ancestors are discussed.
Working to the conservation and good use of the Devonian palaeontological heritage in Floresta, Boyacá (Colombia): a review of teaching case studies …
2019
The Floresta Massif, located in the Eastern Cordillera of Colombia, has a diverse and precious natural heritage. It is one of the areas that contains an exceptional palaeontological heritage of the Middle Devonian not only of Colombia, but also of South America. This heritage is represented by fossil specimens of marine fauna and terrestrial flora (correlated with North America and Europe) of the Floresta and Cuche Formations, respectively. Since 2004, actions made by several academic and research institutions, community and local government have introduced schoolchildren, teenagers and University students to art and science, and have promoted the conservation of palaeontological heritage a…
Age and mineralogy of supergene uranium minerals — Tools to unravel geomorphological and palaeohydrological processes in granitic terrains (Bohemian …
2010
Abstract Uranyl phosphates (torbernite, autunite, uranocircite, saleeite) and hydrated uranyl silicates (normal and beta-uranophane) found in various erosion levels and structures in the Late Variscan granites at the western edge of the Bohemian Massif, Germany, were the target of mineralogical investigations and age dating, using conventional and more advanced techniques such as Laser-Ablation-Inductive-Coupled-Plasma Mass Spectrometry (LA-ICP-MS). Supergene U minerals have an edge over other rock-forming minerals for such studies, because of their inherent ‘clock’ and their swift response to chemical and physical environmental changes on different scales. Uraniferous phoscretes and silcre…
Proterozoic melting in the northern peridotite Massif, Zabargad Island: Os isotopic evidence
1999
The geodynamic history of the three Zabargad peridotite bodies is the key to their significance as samples of the upper mantle. Currently, there are two main hypotheses that differ greatly in their implications for the origin and age of the peridotite complex as a whole. In the first, the Zabargad peridotite bodies all represent young asthenospheric mantle that was juxtaposed with ancient crustal gneisses during the opening of the Red Sea. In the second, the complex may represent a single package of residual mantle and lower crust of Pan-African age that was uplifted during the Miocene. In order to distinguish between these two models, we have analysed five samples of Zabargad peridotite an…
Highly siderophile element geochemistry of the Earth's mantle: new data for the Lanzo (Italy) and Ronda (Spain) orogenic peridotite bodies
2000
Abstract Nine plagioclase/spinel lherzolites from the Lanzo (Italy) and Ronda (Spain) peridotite bodies were analysed for Re, Os, Ir, Ru, Rh, Pd, and Au using a high-precision instrumental neutron activation (INA) procedure after NiS fire assay. Our data conform with previous observations that orogenic lherzolite massifs sampled domains of the subcontinental lithospheric mantle (SCLM) displaying a characteristic enrichment of Ru, Rh and Pd (i.e. the light platinum group elements; PGEs) over Os and Ir. The Pd/Ir, Rh/Ir and Ru/Ir ratios are superchondritic and very similar in both suites (2.46±0.32 vs. 2.42±0.21; 0.46±0.07 vs. 0.45±0.10; 1.99±0.14 vs. 2.25±0.25, respectively). Rhenium and gol…
Geochemistry, single zircon ages and Sm–Nd systematics of granitoid rocks from theGóry Sowie (Owl Mts), Polish West Sudetes: evidence for earlyarc-re…
1998
Granitoid gneisses as well as their migmatitic and anatectic derivates were investigated from theGory Sowie (Owl Mts) Massif of SW Poland in the central West Sudetes. The gneisses and migmatites aretectonically interlayered with paragneisses, and experienced several consecutive tectono-metamorphicevents. Geochemically, the granitoid gneisses are calc-alkaline and similar to orogenic granite suites, whichtherefore lends support to a subduction-related origin. Single zircon Pb–Pb evaporation ages suggest that the gneiss precursors were emplaced between 473 and488 Ma, and most samples analysed contain zircon xenocrysts with minimum ages between 1124 and2620 Ma. An early phase of high-grade met…
Geochronology of the medium to high-grade metamorphic units of the Peloritani Mts., Sicily
2003
The Peloritani Mountains are a fragment of an orogen variably attributed to the Alpine or Hercynian orogeny. On the basis of 39 Ar- 40 Ar, U-Pb and Rb-Sr dating, the main metamorphism of the two medium-high grade metamorphic units, the Mela and Aspromonte Units, and most of the thrusting responsible for stacking the orogenic edifice are seen to be Hercynian. The main thrusting of the Aspromonte Unit over the lower grade units took place at 301€2 Ma. Brittle deformation during Tertiary reactivation of Hercynian thrust planes did not generate any rejuvenation of white micas in the studied sector. Our dataset shows a great complexity and we propose to unravel it by considering different levels…
Revision of "Leptite-gneisses" in the Menderes Massif: a supracrustal metasedimentary origin
2001
The Pan-African basement of the Menderes Massif comprises a regular lithological succession that reaches a thickness of 8 km, the oldest units of which are, in ascending order, so-called leptite-gneisses, a quartzite-sequence transition zone and mica schists. New findings suggest that the protoliths for the leptite-gneisses, proposed to be of volcanic origin in previous studies, were predominantly elastic sediments of litharenitic composition, Geochemical data indicate that the protoliths for the leptite-gneisses were of cratonic provenance. Because they have undergone Pan-African polymetamorphism and are intruded by approximately 550 Ma gneisses of granitic origin, it is believed that the …
Distribution of radioactive elements in three progressively metamorphosed pelite series of the Bohemian Massif
1980
The variations of the content of radioactive elements in pelitic rocks in dependence on the grade of metamorphism were studied in three regions of the Bohemian Massif with a different character and age of metamorphism. The concentrations of Th, U and K were determined by gammaspectrometric method, the major elements Si, Ti, Al, Fe, Mn, Ca, K, P by the X-ray fluorescence method. An increasing mobility of radioactive elements was found with the help of variation diagrams in the higher stages of metamorphism, the migration being apparent especially for Th and usually starting in the garnet or biotite zone. A significant negative correlation of both Th and U content with the content of SiO2 was…