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EN
The paper presents analysis of the residual strength and geometric structure (roughness) of post-failure surfaces of sandstones from Śmiłów and andesites from Wdżar Mountain. The analysis was carried out on the roughness of the surface distribution of samples obtained by extension and shearing tests of rocks. The morphology of these surfaces was characterized by statistical parameters and 2D and 3D maps, from investigations conducted using a Hommel Tester T8000 profilometer.
2
Content available remote Obiekty przyrody nieożywionej wyspy Teneryfa
PL
W artykule zaprezentowano obiekty przyrody nieożywionej, typowe dla wyspy Teneryfa. Opisano skały występujące w obszarze Parku Narodowego Teide, w tym samego wulkanu Teide, a ponadto utwory odsłaniające się w obszarach Montana de Chinyero, Puerto de Santiago, Masca, Los Gigantes i Garachico. W obszarze Teneryfy dominują lawy, bazalty z widocznymi kryształami oliwinu, fonolity i skały maficzne. Można tu również spotkać trachity i andezyty, a na małych plażach czarny piasek wulkaniczny, zawierający pirokseny, oliwiny, skalenie oraz minerały żelaza (magnetyt).
EN
The objects of inanimate nature, typical for Tenerife Island were presented in this article. Rocks of the National Teide Park, including Teide Volcano, moreover rocks from outputs of Montana de Chinyero, Puerto de Santiago, Masca, Los Gigantes and Garachico were described there. Lavas, basalts with visible olivine Crystals, phonolites, and maphic rocks dominate in the area of Tenerife Island. Moreover it is possible to find there trachytes and andesites and on the beaches, black, volcanic sand with pyroxenes, olivines, feldspars and iron minerals (magnetite).
3
Content available remote K-Ar dating of amphiboles from andesite of complex dyke in Dubie (Southern Poland)
EN
This study presents the results of radiometric K-Ar measurements on separated amphiboles from the andesite of the Dubie complex dyke. The data obtained cover the period of (291.3 ± 6.4) Ma, which corresponds to Carboniferous-Permian transition. The age is contemporaneous to the rhyodacitic and basaltoid volcanism of the Kraków region.
EN
Extensional fractures partly filled with calcite showing the characteristics of flowstone have been observed in the andesite from Jarmuta Mt. The isotopic composition of this calcite indicates low-temperature crystallization conditions and its vadose origin. U-Th dating of the flowstone-like calcite indicates ages of [similar to] 2.5-6.5 ka. The calcite grew on a rough and fresh andesite surface, and hence its age may correspond to the age of the extensional fractures. Rhythmically distributed intergrowths of clay minerals present in the calcite may reflect annual climatic oscillations and show that the calcite grew for at least 500 years. The calcite filling the extensional fractures, like the calcite cementing the loosened cataclastic zones cutting the andesite, does not show any features indicating younger deformations. The origin and geometric features of the fractures show that they could have formed in response to increased strike-slip activity within the deep fault zone known as the Dunajec Fault, which may coincide with the fracture zone between the Upper Silesian and Małopolska blocks.
EN
The late Hercynian volcanic complexes in the Sudetes originated due to decompressional melting of the subcontinental lithospheric source region. The volcanic activity started with the calc-alkaline andesite magma in an Early Permian, followed by the picritic relicts and the andesitic assemblage rocks both of tholeiitic affinity. The tholeiitic andesites originated by AFC processes involving mantle-and lower crust-derived material. The differentiation of the andesitic parental magma within high-level magma chamber(s) by AFC processes involving upper crust components yielded the acid volcanic varieties in the area. The geodynamic processes and geological relations correspond with those of continental rift zones.
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