Search results for "Calcar"

Onset of the Messinian Salinity Crisis: Sedimentological, petrographic and geochemical characterization of the pre-salt sediments from a new core (Ca…

2022

The present study aims to reconstruct the environmental changes leading to the Messinian Salinity Crisis during the transition from the Tortonian-Messinian marine conditions to the Messinian evaporitic environments. The core 3AGN2S04, recently drilled in the Caltanissetta Basin (Sicily), was analyzed to reveal the petrographic, mineralogical and geochemical characteristics of the late Tortonian – early Messinian pre-salt sediments. In particular, the facies characterization of the carbonates and organic-rich shales of the Calcare di Base (CdB) member allowed to understand its significance in the paleoenvironmental evolution towards salt deposition and to the reconstruct the brecciation proc…

Il miglioramento energetico nel recupero degli edifici storici. Applicazione al patrimonio architettonico palermitano

L'architettura storica può assumere un ruolo rilevante nel raggiungimento degli obiettivi europei di efficienza energetica per il settore edile, obiettivi che, tuttavia, devono essere compatibili con la conservazione del patrimonio storico e del suo valore culturale. A tal fine è necessario far riferimento ai caratteri specifici dell'architettura storica e alla sua dimensione locale. La presente tesi, sulla base di tale assunto, esamina le prestazioni energetiche degli edifici storici e il loro potenziale miglioramento, concentrandosi sul patrimonio architettonico di Palermo, caso di studio significativo per l'area mediterranea. La ricerca, condotta con riferimento sia alla scala urbana sia…

Laminated carbonate deposits in Roman aqueducts: Origin, processes and implications

2013

Carbonate deposits in Roman aqueducts of Patara and Aspendos (southern Turkey) were studied to analyse the nature of their regular layering. Optical microscopy and electron-backscattered diffraction results show an alternation of dense, coarsely crystalline, translucent laminae composed of bundles and fans of elongate calcite crystals with their c-axes parallel to the long axis, and porous, fine-grained laminae with crystals at near-random orientation. The ?18O and ?13C data show a strong cyclicity and anti-correlation, whereby high and low ?18O values correspond to dense columnar and porous fine-grained laminae, respectively. Geochemical analyses show similar cyclic changes in carbonate co…

Post-fire hydrological response and suspended sediment transport of a terraced Mediterranean catchment

2017

In July 2013, a wildfire severely affected the western part of the island of Mallorca (Spain). During the first three post-fire hydrological years, when the window of disturbance tends to be more open, the hydrological and sediment delivery processes and dynamics were assessed in a representative catchment intensively shaped by terracing that covered 37% of its surface area. A nested approach was applied with two gauging stations (covering 1.2 km2 and 4.8 km2) built in September 2013 that took continuous measurements of rainfall, water and sediment yield. Average Suspended Sediment Concentration (1,503 mg l-1) and the maximum peak (33,618 mg l-1) were two orders of magnitude higher than tho…

A new Neoplatyura Malloch from Finland (Diptera, Keroplatidae).

2014

The genus Neoplatyura Malloch is globally represented by 50 species, of which four are European species. In this article a new European Neoplatyura from Finland is described. The new species, Neoplatyura noorae Salmela, sp. n. is a dark brown species with tibial bristles arranged in rows. The new species is here reported from seven localities in Finnish Lapland. Based on available data, the new species occurs in mires, especially in calcareous rich fens.

230Th/U-dating of carbonate deposits from ancient aqueducts

2016

Abstract Carbonate deposits in aqueducts, known as calcareous sinter, can reach a considerable thickness and are commonly annually laminated. Environmental and palaeoclimate proxies measured in calcareous sinter samples, such as stable oxygen and carbon isotopes and trace elements, can provide important high-resolution information on hydrological conditions, temperature, and local precipitation in the catchment area of an aqueduct. In order to utilize the proxy data for palaeoclimate reconstruction, the sinter deposits must be dated by annual laminae counting and more precisely by 230 Th/U-dating. The major problem of 230 Th/U-dating of calcareous sinter in aqueducts is the relatively large…

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages. A comparison with micro-X-ray …

2009

Durability of calcarenitic hypogea in the underground cultural heritage of Palermo (Sicily)

2011

The paper deals with the stability conditions of hypogea, several hundred m 2 wide, dating from the Punic period to the XIX century, dug out of the calcarenitic table that makes up the bedrock of the Plain of Palermo in the Fossa della Garofala. This work concerns the influence that the shape of the hypogea and the characteristics of the lithotypes wields on the instability and decay phenomena taking place, by mean of laboratory tests on the calcarenite and parametric numerical models. The comparison between the numerical models and the actual instability phenomena validated the use of the empirical formula of Hoeck to the mechanical characterization of complex structured rock-mass in soft …

Facilitated transport of diuron and glyphosate in high copper vineyard soils.

2007

6 pages; International audience; The fate of organic herbicides applied to agricultural fields may be affected by other soil amendments, such as copper applied as a fungicide. The effect of copper on the leaching of diuron and glyphosate through a granitic and a calcareous soil was studied in the laboratory using sieved-soil columns. Each soil was enriched with copper sulfate to obtain soil copper concentrations of 125, 250, 500, and 1000 mg kg(-1). Glyphosate leaching was influenced by soil pH and copper concentration, whereas diuron leaching was not. In the calcareous soil, glyphosate leaching decreased as copper levels increased from 17 mg kg(-1) (background) to 500 mg kg(-1). In the gra…

Occurrence and regional distribution of calcareous concretions in the rat pineal gland.

1978

Serial sections of 90 Sprague-Dawley rat brains with the pineal in situ were scanned to determine the occurrence and regional distribution of calcareous concretions within the pineal gland and its surrounding leptomeningeal tissue. In 90% of the cases examined concretions were found in varying number and appearance, predominantly lying in the dorsal region of the pineal gland and in the distal portion of the pineal stalk. Discussing the hypothesis advanced by Lukaszyk and Reiter (1975) that the origin of pineal concretions may be related to a neurosecretory process involving a pineal carrier protein, called neuroepiphysin, it is thought that, in view of the intra- and extra-pineal occurrenc…