Search results for "Sediment"
showing 10 items of 1648 documents
Integrated stratigraphy of the Norian GSSP candidate Pizzo Mondello section (Sicani Mountains, Sicily)
2008
OSL dating of sediments from the Gobi Desert, Southern Mongolia
2010
Abstract The present study focuses on the chronological relationship between alternating dune sand and silty water-lain sediments in the central part of the Khongoryn Els dune field in the Gobi Desert, Southern Mongolia. The 23 m high section evolved from the construction of a natural dam by west–east moving sand dunes and fluvial inundation by a river system from the mountain ranges in the south. To resolve the chronology of events, optically stimulated luminescence (OSL) dating was applied and from sedimentological and geochemical analysis the depositional processes could be characterised. Quartz OSL dating of these sediments is hindered by feldspar contamination. Thus, dating of coarse-g…
Systems tracts and depositional sequences in a carbonate setting: a study of continuous outcrops from platform to basin at the scale of seismic lines
1991
Abstract The application of sequence stratigraphy concepts to carbonates is feasible and this paper presents an example of its successful application. The continuity and lateral extent of outcropping sedimentary sections observed at the scale of a seismic line from platform to basin in the Southern Vercors Plateau (western Alps, France) confirm the validity of sequence stratigraphy concepts when applied to carbonate depositional systems. From the stratal patterns displayed in outcrop, we determined that carbonate lowstand systems tracts are major components in the basin, even in the deep pelagic realm. Transgressive and highstand systems tracts are very thin, a response to starvation. In co…
River channel evolution and tsunami impacts recorded in local sedimentary archives – the ‘Fiume Morto’ at Ostia Antica (Tiber River, Italy)
2020
Micro- to macro-scale internal structures, diagenesis and petrophysical evolution of injectite networks in the Vocontian Basin (France): implications…
2015
27 pages; International audience; This study discusses the characteristics of two Lower Cretaceous injectite networks in the Vocontian Basin (SE France) using combined structural, sedimentary, diagenetic, and petrophysical analyses. Internal structures, at both the macro- and micro-scale, and diagenetic phases characterising these injectite networks have been described. Simultaneously, precementation porosity values were estimated and parameters controlling the geographical distributions of these values were analysed and statistically tested. All of the data were integrated so as to reconstruct the spatial evolution of the porosity from the time of injection to modern times through five maj…
Preface: Proceedings of the 14th IASWS international conference
2018
Preface to the Proceedings of the 14th IASWS international conference
Strontium and argon isotopic homogenization of pelitic sediments during low-grade regional metamorphism: The pan-African upper Damara sequence of Nor…
1979
Abstract The fine mineral fractions extracted from pelitic sediments of the Eocambrian upper Damaran Mulden Group were subjected to a detailed isotopic study by the Rb-Sr and K-Ar methods in combination with a mineralogical analysis by X-ray diffractometry. The sediments contain two major parageneses of metamorphic origin which can be related to two separate low-grade regional metamorphic events of anchizonal intensity with temperatures between 250 and 300°C and pressures up to 2 kbar. These events are dated at about 535 m.y. and 455 m.y. respectively (with λ( 87 Rb) = 1.42 × 10 −11 yr −1 ). Anomalously high K-Ar ages on samples from specific stratigraphic horizons can be related to open sy…
Sicily’s fold–thrust belt and slab roll-back: the SI.RI.PRO. seismic crustal transect
2016
Sicily is a thick orogenic wedge formed by (1) the foreland (African) and its Sicilian orogen and (2) the thick-skinned, Calabrian–Peloritani wedge. The crust under central Sicily, from the Tyrrhenian margin to the coastline of the Sicily Channel, has been investigated by the multidisciplinary (SI.RI.PRO.) research project. The project dealt with the nature and thickness of the crust and depth and geometry of the Moho, which is essential in formulating subduction models and improving the knowledge of African and Tyrrhenian–European lithospheres. The results resolve features such as (1) the main orogenic wedge, (2) the very steep, NW–SE-trending regional monocline suggesting inflection of th…
Porewater pressure control on subglacial soft sediment remobilization and tunnel valley formation: A case study from the Alnif tunnel valley (Morocco)
2014
25 pages; International audience; In the eastern part of the Moroccan Anti-Atlas Mountains, the Alnif area exposes a buried Ordovician glacial tunnel valley (5 km wide, 180 m deep) cut into preglacial marine sediments. The preglacial sedimentary sequence, deposited in a marine environment, is characterized by a typical "layer-cake" configuration of permeable (sand) and impermeable (clays and early-cemented sandstones) layers. At the base of the tunnel valley, a discontinuous and fan-shaped glacial conglomeratic unit 10 to 15 m thick occurs, erosively deposited over preglacial marine sediments. The conglomeratic unit is composed of preglacial intraclasts embedded within a sandy matrix. Both …
Interpretación paleohidrológica y geoarqueológica del substrato romano y musulmán de la ciudad de Valencia
1990
SE ESTUDIA EL REGISTRO GEOARQUEOLOGICO, ROMANO Y MUSULMAN DE LA CIUDAD DE VALENCIA. SE OBSERVAN CUATRO NIVELES DE SEDIMENTACION DIFERENCIADOS: UN SUELO HIDROMORFO DE EPOCA PRERROMANA, LIMOS Y ARENAS DE DESBORDAMIENTO EN FACIES OVERBANK Y CREVASSE SPLAY DEL PERIODO ROMANO, ARCILLAS Y LIMOS ORGANICOS TARDO ROMANOS Y, FINALMENTE, SECUENCIAS VERTICALES DE SEDIMENTOS DE GRANO MUY GRUESO EN FACIES DE BARRAS Y DEPOSITOS DE CANAL DE EPOCA MUSULMANA. LOS DEPOSITOS DE INUNDACION DE EPOCA HISTORICA CORRESPONDEN A FASES DE PROGRADACION CONTINENTAL EN LA LLANURA COSTERA. (A)