Results 11 to 20 of about 6,575 (164)
Troubles With Tubules: How Do Iron-Mineral Chemical Gardens Differ From Iron-Mineralized Sheaths of Iron Oxidizing Bacteria? [PDF]
GeobiologyABSTRACT Microscopic tubules and filaments composed of iron minerals occur in various rock types of all ages. Although typically lacking carbonaceous matter, many are reasonably interpreted as the remains of filamentous microorganisms coated with crystalline iron oxyhydroxides. Iron‐oxidizing bacteria (IOB) acquire such a coating naturally during life.
Podbielski M +8 more
europepmc +2 more sources
Gypsum Gardens: Self-Assembled Tubular Structures of Calcium Sulfate with Relevance for the Detection of Extraterrestrial Life. [PDF]
Angew Chem Int Ed EnglChemical gardens are self‐assembled architectures with “life‐like” morphologies that form in the absence of any biological activity. Here we show that such structures can also be obtained by contacting reservoirs of calcium and sulfate ions, under conditions that plausibly emulate those prevailing on early Mars.
Reigl S +5 more
europepmc +2 more sources
Journal of Geophysical Research: Solid Earth, Volume 128, Issue 12, December 2023., 2023 Abstract Full‐field numerical modeling is a useful method to gain understanding of rock salt deformation at multiple scales, but it is quite challenging due to the anisotropic and complex plastic behavior of halite, together with dynamic recrystallization processes. This contribution presents novel results of full‐field numerical simulations of coupled
B. Hao +6 more
wiley +1 more source
Tectonics, Volume 42, Issue 12, December 2023., 2023 Abstract The Cadomian Orogeny produced a subduction‐related orogen along the periphery of Gondwana and configured the pre‐Variscan basement of the Iberian Massif. The architecture of the Cadomian Orogen requires detailed structural analysis for reconstruction because of severe tectonic reworking during the Paleozoic (Variscan cycle). Tectonometamorphic
Diana Moreno‐Martín +5 more
wiley +1 more source
Estudios Geologicos, 2000 La Formación de Utrillas, aflorante en el borde sur de la cuenca Vasco-Cantábrica, está formada por materiales mayoritariamente areniscosos depositados en un ambiente fluvial.
J. Arostegui +3 more
doaj +1 more source
Geogaceta, 2023 Los xenolitos granulíticos del volcán de La Encomienda (Campo Volcánico de Calatrava) representan un conjunto de composición félsica peralumínica.
David Orejana García +2 more
doaj +1 more source
Caracterización composicional de los depósitos arenosos actuales generados en el Sistema Central
Estudios Geologicos, 1989 Se caracteriza composicionalmente la fracción ligera arenosa de los depósitos detríticos actuales generados en zonas de cabecera de arroyos que drenan macizos del Sistema Central con distintas litologías (plutónicas, gnéisicas o pizarras-esquistos ...
A. Tortosa, M. Palomares, J. Arribas
doaj +1 more source
Clima y ocupaciones en la Galería de Estatuas (Atapuerca, Burgos) en los últimos 14.000 años: Relatos de una estalagmita [PDF]
Munibe Antropologia-Arkeologia, 2010 Los espeleotemas constituyen uno de los principales registros para establecer secuencias evolutivas paleoclimáticas del Cuaternario. Además, en cavidades que presentan evidencias de ocupación humana registran los cambios ambientales producidos en el ...
Martínez-Pillado, V. +4 more
doaj
Materiales de Construccion, 2003 Some physical properties of three ornamental granites with different superficial finishes (polished, sawn and flamed) were quantified by standard tests. These granites are commercially known as Rosa Porrino, Rosavel and Blanco Alcazar.
A. Rojo, F. J. Alonso, R. M. Esbert
doaj +1 more source
Estudio petrológico del plutón de Trujillo (Cáceres. España)
Estudios Geologicos, 1984 En función del estudio petrológico, el plutón de Trujillo está constituido por una adamellita porfídica que ha cristalizado en tres fases, presentando una cuarta de alteración.
J. Guijarro +3 more
doaj +1 more source