Search results for "Rock"
showing 10 items of 1160 documents
Oltre i limiti della rappresentazione. La genealogia delle immagini di guerra in Harun Farocki
2017
Il saggio ripercorre l'opera di Harun Farocki a partire dal mondo in cui essa ha messo in questione elaborandole le immagini di guerra
Coupled petrological-geodynamical modeling of a compositionally heterogeneous mantle plume
2018
Abstract Self-consistent geodynamic modeling that includes melting is challenging as the chemistry of the source rocks continuously changes as a result of melt extraction. Here, we describe a new method to study the interaction between physical and chemical processes in an uprising heterogeneous mantle plume by combining a geodynamic code with a thermodynamic modeling approach for magma generation and evolution. We pre-computed hundreds of phase diagrams, each of them for a different chemical system. After melt is extracted, the phase diagram with the closest bulk rock chemistry to the depleted source rock is updated locally. The petrological evolution of rocks is tracked via evolving chemi…
La década contestataria
2017
Con ocasión de un trascendente proceso electoral, Nicolás Sarkozy descargó sobre el Mayo Francés, y por tanto, sobre la izquierda liderada en aquel momento por Segolene Royal, la responsabilidad por los males de la sociedad contemporánea. Este debate, planteado igualmente en Norteamérica de manera cíclica por los Republicanos para desacreditar a los Demócratas, ha tenido ya sucesivos episodios. Hay otra imputación, no sólo a Mayo del 68, sino al conjunto de procesos de protesta y transformación que caracterizaron a toda la década de los sesenta en Occidente y en otras sociedades: la rebeldía que asociamos a esos años es en realidad la expresión de la necesidad de transformación de las empre…
LA-ICP-MS U–Pb dating of detrital rutile and zircon from the Reynolds Range: A window into the Palaeoproterozoic tectonosedimentary evolution of the …
2014
Abstract The Palaeoproterozoic Reynolds Range of the Arunta Region, central Australia, comprises a series of shallow marine clastic sediments (Reynolds Range Group) which overlies deeper water sequences of turbidites (Lander Rock Formation) and minor sandstones (“unnamed sandstone”). U–Pb age data collected from detrital rutile and zircon in these rocks indicates these sequences contain very similar age spectra, although with a notable and important shift to younger ages within the stratigraphically younger Reynolds Range Group. Detrital zircons from the “unnamed sandstone” directly underlying the unconformity with the Reynolds Range Group contain a major age component at ca. 1860 Ma, toget…
Student Author of the Year Award 2009
2009
The ‘‘Student author of the Year Award’’ is made for an outstanding paper in which an undergraduate or graduate student played a key role in the research and publication. The recipient of this award for 2009 is Ruben Diez Fernandez for his contribution, co-authored with Jose R. Martinez Catalan 3D Analysis of an Ordovician igneous ensemble: A complex magmatic structure hidden in a polydeformed allochthonous Variscan unit Journal of Structural Geology, Volume 31, Issue 3, March 2009, Pages 222–236. The Editors have selected this paper out of many student submissions in 2009. The basis of this paper is detailed field mapping, metamorphic petrology and structural analysis. These clearly establ…
The N Variscan margin of the Ruhr coal district (Western Germany): structural style of a buried thrust front?
1988
The Ruhr coal district represents part of an external fold and thrust belt of the Variscan orogen in central Europe. Extensive mining exposed molasse-type, coal-bearing clastic sequences of Upper Carboniferous age, deformed by folding and thrusting. Thrusts range in scale from decameters to 40 kilometers along strike but displacements are below 2.5 km. They are distributed in various stratigraphic levels and no regional detachment horizon is exposed. Displacement is mainly towards NW (towards the foreland) but also towards SE. The thrusts are bound to stockwerk-tectonics and die out towards depth frequently antithetic to the exposed strata. Folds vary in wavelength from decameters to more t…
Trace-element partitioning between amphibole and silicate melt.
2007
Knowledge of the partitioning behavior of trace elements between solid and liquid is a prerequisite for modern igneous and mantle petrology. Most of the mathematical models simulating melt generation, migration and evolution within the mantle and/or the crust require the availability of reliable solid/liquid partition coefficients for the mineral phases involved in the process. Calcic amphiboles are extremely important for the understanding of lithospheric processes because of both their common occurrence in a variety of igneous and metamorphic rocks types and their capability of hosting a large number of geochemically important trace elements. A series of studies on the partitioning behavi…
Acoustic Emission Waveform Picking with Time Delay Neural Networks during Rock Deformation Laboratory Experiments
2020
Abstract We report a new method using a time delay neural network to transform acoustic emission (AE) waveforms into a time series of instantaneous frequency content and permutation entropy. This permits periods of noise to be distinguished from signals. The model is trained in sequential batches, using an automated process that steadily improves signal recognition as new data are added. The model was validated using AE data from rock deformation experiments, using Darley Dale sandstone in fully drained conditions at a confining pressure of 20 MPa (approximately 800 m simulated depth). The model is initially trained by manual picking of five high-amplitude waveforms randomly selected from t…
Compte rendu de : Luc Robène et Solveig Serre (dir.), Punk is not dead. Lexique franco-punk, Paris, Nova, 2019, 200 p.
2020
International audience
Further evidence for an early Carboniferous (∼340 Ma) age of high-grade metamorphism in the Saxonian granulite complex
1998
U–Pb and Pb–Pb zircon ages for metamorphic zircons from granulites in the Saxonian granulite complex are reported, using the SHRIMP ion microprobe, conventional multigrain and single-gain techniques and the evaporation method. This is complemented by a Pb–Pb evaporation age for a post-granulite granite emplaced into the schist mantle around the granulites during uplift of the complex. We also demonstrate that zircon ages are not reset during high-grade metamorphism, as commonly argued, but have a very high closure temperature and usually preserve the isotopic composition reflecting the time of their formation. Multifaceted zircons from four granulite samples that probably grew close to the …