Search results for "TCR"

Sedimentology and vertebrate fossils of the Frasnian Ogre Formation, Gurova outcrops, eastern Latvia

2020

Combined sedimentological and palaeontological study of the siliciclastic sequence of the Ogre Formation in the easternmost area of its distribution in Latvia was aimed at the facies analysis of the deposits and at detailed observation of the taxonomical and taphonomical peculiarities of the fossil vertebrate assemblage. Two facies associations, tidally-influenced fluvial channels and lateral tidal bars, have been identified in exposures along the Gurova River. Sedimentological evidences suggest that the studied deposits were formed in the fluvial environment with strong tidal influence. The sedimentary concentrations of vertebrate remains, dominated by the antiarch Bothriolepis maxima, por…

¿Cabe hablar de una «generación de la crisis»? Discusión en torno a una noción sobreexplotada

2018

This article states that nowadays there is an overuse (or a misuse) of the «Generation» idea. The discussion among many authors over the «Generation of crisis» concept suggests that it is useful to outline the characteristics of the target of population of the collective of youth who are mainly affected by the economic and social crisis over the past years. Nevertheless, through analyzing the meanings of the «Generation of Crisis» made by Mannheim, Ortega and other classic authors, it is clear that the social class approach together with the generational one are needed to define this concrete concept. The conclusion of the articleis that both approaches are seen as underpinning their utilit…

New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean real…

2019

The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary ph…

The Santa Ninfa Cave (Belice Valley): hydrogeochemical features and relationships with neotectonics

2020

The Santa Ninfa Cave (SNC) develops in an outcrop of Messinian gypsum, located in the heart of the zone struck by the 1968 seismic sequence of the Belice valley. It is composed of different levels of sub-horizontal galleries, the lowest of which is characterized by perennial flowing water, running along the water table. From the hydrogeological point of view, it configures as an open circuit, both inflowing and outflowing from/to neighboring aquifers. The geochemical facies of groundwater collected in the SNC is compatible with a meteoric recharge chemically interacting with evaporitic deposits. The most relevant geochemical feature is the mixing between a small tributary of sulfur water wi…

Partitioning between “wedge-top” river- and wave-dominated successions: an example from the late Tortonian — early Messinian Terravecchia Formation (…

2011

AbstractDetailed field sedimentological and facies analyses have been performed in the Terravecchia Formation cropping out in NW Sicily, in order to differentiate and describe, for the first time, wave- and river-dominated shallow-marine (deltaic) siliciclastic successions. The latter were deposited filling syntectonic basins, developed between the late Tortonian and early Messinian time, within the wedge-top depozone of the Sicilian Foreland Basin System. It has been observed that river-dominated successions, recording the deposition of small fan-deltas are characterized by fining- to coarsening upward, transgressive-regressive sequences which were mostly deposited filling relatively narro…

Solution and recrystallisation processes and associated landforms in gypsum outcrops of Sicily

2003

Abstract Four small areas of Messinian (Upper Miocene) age gypsum, outcropping in western Sicily, are described. Messinian age evaporites are found in Sicily over a 1000-km 2 area. Here, gypsum outcrops extensively as a consequence of soil erosion induced by human impact. Geomorphological maps show how the rocky surfaces are characterized by a wide range of forms. There are large, medium, small, and microsized forms, which can be identified as belonging to different morphotypes. The morphotypes can be classified into two main categories: those that originated by solution and those that originated through recrystallisation. Four areas, illustrated by geomorphological maps, were specifically …

1993

The miocene deposits of the Quesa basin (Betic foreland) outcrops in the central part of the Valencia province (Spain). Quesa basin is a subsiding hanging-wall basin related to an ENE-WSW listric fault system. The deposits of this basin are formed by a 440 metres thick sequence of red clays, containing few intercalations of sandstones and micritic white limestones, and breccias. The upper 70 metres of this sequence is a wedge-shaped unit composed by breccias containing megablocks, wich interfinger with tabular limestones towards the central part of the basin. The breccias are foot-wall derived debris fiow deposits formed during normal faulting. A mammal site close to the base of the breccia…

Architecture and tectono-stratigraphic evolution of the intramontane Baza Basin (Bétics, SE-Spain): Constraints from seismic imaging

2017

The Baza basin is a large Neogene intramontane basin in the Bétic Cordillera of southern Spain that formed during the Tortonian (late Miocene). The Bétic Cordillera was produced by NW–SE oblique convergence between the Eurasian and African Plates. Three seismic reflection lines (each 18 km long; vibroseis method) were acquired across the Baza basin to reveal the architecture of the sedimentary infill and faulting during basin formation. We applied rather conventional CDP data processing followed by first arrival P-wave tomography to provide complementary structural information and establish velocity models for the post-stack migration. These images show a highly asymmetric structure for the…

Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland).

2015

18 pages; International audience; Soft-sediment deformation structures are being increasingly used as a tool for reconstructing palaeoenvironments and porewater pressure conditions in glacial settings. However, the potential of hydrofractures and clastic injections in the reconstruction of ice dynamics remains poorly constrained. This paper presents the results of a detailed study of a clastic injection network outcropping in the Sólheimajökull forefield (South Iceland). Sedimentological descriptions are combined with microscopic to macroscopic analyses of clastic injection geometries, sediment-fills, and cross-cutting relationships. The 250 m long and 20 m high exposure observed along the …

Fluid-pressure controlled soft-bed deformation sequence beneath the surging Breiðamerkurjökull (Iceland, Little Ice Age).

2009

16 pages; International audience; The general subject of this paper is subglacial deformation beneath Breiðamerkurjökull, a surging Icelandic glacier. More specifically it discusses the evolution and the role of fluid pressure on the behaviour of subglacial sediments during deformation. During Little Ice Age maximum, the two outcrops studied, North Jökulsarlon (N-Jk) and Brennhola-Alda (BA), were located at 2550 m and 550 m respectively from the front of the Breiðamerkurjökull. Sedimentological analysis at the forefield of the glacier shows thick, coarse glaciofluvial deposits interbedded with thin, fine-grained shallow lacustrine/swamp deposits, overlain by a deformed till unit at N-Jk. BA…