Search results for "transgression"

Quaternary development and evolution of the sedimentary environments in the Central Mediterranean Spanish coast

1995

Abstract The reconstruction of the evolutive phases of the Mediterranean Spanish Central sector during the Late Quaternary is the aim of this work. From geomorphological, sedimentological and chronometrical studies, different morphostratigraphic units are determined. Results point out the development of several transgressive phases. The older one go back to isotope stage 7. The Eemian transgression is broadly recorded, and its coastline was near the present one. During the Flandrian episode, the sea surpassed the current coastline in the northern coastal plain, while in the meridional littoral erosive notches were formed between +1 and +2 m. During the regressive events, we find the prograd…

"And then they found her body" : T. S. Eliot's corporeal Cocktail party

2003

Geomorphological evolution of the River Loukkos estuary around the Phoenician city of Lixus on the Atlantic Littoral of Morocco

2009

The ancient city of Lixus, today situated on a hill on the right bank of the River Loukkos, 4km from the coast, was founded on the shore of a brackish lagoon that was sheltered from Atlantic storms. This geographical context provided the city with one of the best Phoenician harbors and abundant fishing resources, and allowed access to the Gharb cattle farming resources and cereal production systems. In this study, the historical evolution of the Loukkos estuarine environment is reconstructed through geomorphological and sedimentological analyses, combined with cartographic, archaeological, and geographical data. The outcomes reveal the progressive infilling of the estuarine lagoon of Lixus …

Nouvelles méthodes de traitement de signaux multidimensionnels par décomposition suivant le théorème de Superposition de Kolmogorov

2010

The processing of multidimensional signal remains difficult when using monodimensional-based methods. Therefore, it is either required to extend monodimensional methods to several dimensions, which is not always possible, or to convert the multidimensional signals into 1D signals. In this case, the priority is to preserve most of the properties of the original signal. In this context, the Kolmogorov Superposition Theorem offers a promising theoretical framework for multidimensional signal conversion. In 1957, Kolmogorov demonstrated that any multivariate function can be written as sums and compositions of monovariate functions.We have focused on the image decomposition according to the supe…

Environmental evidence of Valencia lagoon coastal barrier stabilization from 8500 BP to Present. Climate and eustatic variations

2020

Abstract The Albufera de Valencia is one of the largest lagoon in the Spanish Mediterranean. Two continuous borehole cores reaching depths of 8 and 14 m in the northern part of the lagoon underwent sedimentological, micropaleontological and biological study. The organic content was also analysed, and 14C radiometric dating and amino acid racemization were performed. Study of the content of benthic foraminifera and n-alkanes and alkanoic acids in the lagoon sedimentary record identified several periods. The core records showed seven different environments: alluvial; freshwater marsh; brackish marsh; brackish lagoon; brackish lagoon with marine connection, backbarrier flat, and backshore. The…

Proposal of a reference section and point for the Cambrian Series 2-3 boundary in the Mediterranean subprovince in Murero (NE Spain) and its intercon…

2011

The classical lower-middle Cambrian boundary is approximately equivalent with the boundary of the Cambrian Series 2 and 3, which is now in the process of definition by the International Subcommission on Cambrian Stratigraphy. Currently, there are two oryctocephalid trilobite species first appearance data (FAD) that are suggested as possible markers of this level: Ovatoryctocara granulata Tchernysheva, 1962 and Oryctocephalus indicus (Reed, 1910), respectively. Until now neither of these two species has been recorded in the Mediterranean subprovince or Baltica. As a result, in these regions a level potentially correlating with either the FAD of Ovatoryctocara granulata or Oryctocephalus indi…

Witnesses of the early Pliocene sea-level rise in the Manilva Basin (Málaga, S Spain)

2020

The Sierra de la Utrera, a relief in the Manilva Basin (Malaga, SW Spain), shows bored surfaces at different heights above present-day sea level, from 96 m to 287 m. Borings occur in the eastern, central, and western parts of the Canuto de la Utrera, a prominent gorge in the central southern part of the relief excavated in Mesozoic limestones, as well as on the western end of the Canuto Chico, a smaller canyon in the northern part. Pliocene marine deposits fossilized the bored surfaces. Bored boulders of the substrate are embedded in the Pliocene sediments. The traces Gastrochaenolites ispp., Entobia ispp., Caulostrepsis ispp., Circolites kotoucensis, and Ericichnus asgaardi have been ident…

Environmental evolution and mid–late Holocene climate events in the Valencia lagoon (Mediterranean coast of Spain)

2016

Integration of geomorphological, stratigraphic, malacological, sedimentological and micropalaeontological techniques and14C dating allows us to characterise the processes and evolution of the coastal barrier–lagoon system of Valencia (Spain), from the middle Holocene to the historical epoch, as well as the responses to global climate events. Four stages are recognised. Phase 1: around 8240 ± 80 cal. yr BP, a brackish lagoon of moderate energy and in restricted environment was formed, with an energy peak that could correspond to the maximum Holocene marine transgression. Dating (8240 ± 80 cal. yr BP) carried out in peat corresponds to a cold cycle and low water levels in inland lakes of the …

Facies variations in response to Holocene sea-level and climate change on Bora Bora, French Polynesia: Unravelling the role of synsedimentary siderit…

2017

International audience; Five mixed carbonate-siliciclastic sedimentary facies were identified in the barrier-reef lagoon of Bora Bora using microfacies and statistical analyses of 70 sediment samples taken at high resolution from two vibrocores. Fades and fades successions were interpreted with respect to Holocene sea-level and climate changes. The windward lagoon core is characterized by sideritic marly wackestones and foraminifera-sideritic wackestones, deposited around 7700 years BP (years before present) during the early-mid Holocene transgression. At that time, extensive weathering and erosion of iron-bearing minerals from the volcanic island, due to a wetter climate, were expressed in…

A foraminiferal assemblage as a bioevent marker of the main Ladinian transgressive stage in the Betic Cordillera, southern Spain

2005

Abstract The Betic Cordillera comprises the mountain range in the southern Iberian Peninsula that extends from Cadiz to Alicante, which displays typical features of alpine cordilleras. The Betic Cordillera includes two large geological tectonic domains, namely an External Zone, and an Internal Zone. The External Zone is essentially composed of epicontinental Triassic rocks that consist of the Buntsandstein, Muschelkalk and Keuper facies. The Buntsandstein facies rarely occur in outcrops, whereas the Keuper stratigraphic successions are truncated. The Muschelkalk facies frequently displays complete successions that are very useful for interpreting the Ladinian stage palaeogeography. The Musc…