Search results for "petrography"
showing 10 items of 138 documents
Ethnoarchaeometric Study of the Traditional Cooking Ware Production Centre of Pabillonis (Sardinia): Investigating Raw Materials and Final Products
2010
Ethnoarchaeometry can be used to test assumptions in ceramic provenance studies. Within the Late Roman Cooking Wares (LRCW’s) commercialised in the Western Mediterranean some fabrics such as Fabrics 1.2, 1.6/1.7 and 1.9 (Fulford and Peacock, 1984) have been proposed to have a Sardinian origin. This motivated a specific project to explore the nature of cooking pottery on the island and the raw clays as well as the production technologies that have been used traditionally for their manufacture. In this paper, the traditional cooking pottery making in Pabillonis (Oristano province) was studied. First, a field survey in the area of Pabillonis was undertaken in order to locate the raw materials …
Basalt magmatism along the passive continental margin of SE Brazil (Campos basin)
1992
The SE-Brazil passive continental margin is characterized by tholeiitic magmatism that is particularly widespread in the marginal Campos basin, facing the inland flood basalts of the adjacent Parana basin. Campos magmatism is represented by Early Cretaceous (EC; 134–122 Ma) flood basalts and minor Upper Cretaceous-Early Tertiary basalt flows and intrusives, which were emplaced in a basin with attenuated crustal thickness (20 km). Petrography, mineral chemistry, wholerock geochemistry and Sr−Nd isotope composition emphasize that the EC-Campos basalts have suffered extensive seawater interaction which caused enrichment in MgO, FeO total, K2O, Rb and Ba, and depletion in SiO2 and CaO, while Zr…
The White Stone of South-Eastern Sicily: Urban and Territorial Identity
2017
La Sicilia è un territorio fortemente "segnato" dall'impiego massiccio della ricca varietà di materiali lapidei che la natura ha messo a disposizione: materia prima dalle differenti qualità petrografiche, colore, caratteristiche tecniche e con una vasta possibilità di impiego, sia come elemento costruttivo sia come pietra ornamentale. La "pietra bianca" di Siracusa, il basalto dell'Etna, la "pietra forte" del ragusano, la pietra di Sabucina di Caltanissetta e Niscemi, le calcareniti e le rocce tufacee delle cave di Carini e Aspra, il calcare grigio di billiemi nel palermitano e il tufo calcareo di Agrigento, caratterizzano gran parte degli insediamenti antropici dell'isola, espressione di u…
Petrography, mineralogy and geochemistry of a primitive pumice from Stromboli: implications for the deep feeding system
2011
We describe the field relations, petrographic, mineralogical and geochemical characteristics of an exceptional “ golden ” pumice belonging to a tephra layer exposed on the summit area of Stromboli volcano, Italy. Pumice sample PST-9 comes from a fallout deposit older than a spatter agglutinate sequence emplaced during the twentieth century. The eruption that produced it had a size exceeding that of intermediate paroxysms but was smaller than large-scale, spatter-forming, paroxysms from the sixteenth century and 1930 A.D. Lapilli are strongly vesicular and crystal-poor, similar to other “ golden ” pumices. Modal proportions include 89 vol% glass, 8 vol% clinopyroxene, 1–2 vol% olivine and 1–…
Amygdaloidal basalts: Isotopic and petrographic evidence for non-diagenetic crustal source of carbonate inclusions
1980
Even though carbonate amygdules in volcanics are generally assumed to be diagenetic in origin, the authors are of the opinion that almost all carbonate inclusions in the investigated amygdaloidal volcanic rocks from Sicily (Italy), Pindos (Greece) and Bohemia (Czechoslovakia), have a different origin. On the basis of a mineralogical, petrological and geochemical study these “amygdules” are interpreted as being remains ofmagmatic incorporation of carbonate. Therefore, the identification of carbonate globules in volcanics purely on field observations, is inadequate to distinguish true amygdules from carbonate assimilation remnants. A nomenclature of the various types of inclusions is proposed…
Fracture stratigraphy and oil first migration in Triassic shales, Favignana Island, western Sicily, Italy
2021
This study aims at evaluating the control exerted by fracture stratigraphy and diagenetic processes on oil first migration through an outcropping, mixed carbonate-siliciclastic succession. The present work included results of sedimentological, paleontological, mineralogical, petrographic, structural, and microstructural analyses carried out on organic-rich shales exposed at the Favignana Island of Sicily, Italy. The analyses focus on Upper Triassic yellowish siltstones and greyish laminated dolomitic limestones, which form a 10's of m-thick succession exposed along the westernmost portion of the Sicilian fold-and-thrust belt. The studied succession deposited in a coastal lagoon associated t…
Composantes culturelles et Premières productions céramiques du Bronze ancien dans le sud-est de la France
2012
The collective research project "Cultural components of the first pottery productions of the Early Bronze Age in Southeast France" derives from renewal of documentation on the Early Bronze Age in the southeast Rhodanian region and new approaches to the Bell Beaker period, particularly in the southern part of Southeast France. In 1998, the Riva del Garda conference constituted a high point in Bell Beaker research at a European scale, of which the consequences and questions motivated the collective project for an overview of the transition from the end of the Neolithic to the Early Bronze Age in a large southeastern quarter of France. In these regions, issues relating to the future of Bell Be…
Obsidians of Pantelleria (Strait of Sicily): A Petrographic, Geochemical and Magnetic Study of Known and New Geological Sources
2020
Abstract This paper provides new petrochemical and paleomagnetic data from obsidian sub-sources on the island of Pantelleria, exploited since the Neolithic. Data has been obtained from 14 obsidian samples from 4 locations: Fossa della Pernice (2 sites), Salto la Vecchia and Balata dei Turchi. Here, we aim to better characterize these obsidians using a cross-disciplinary and multi-analytical approach, to further understand their archaeological significance. Major element analyses (EMP) have enabled two compositional super-groups to be distinguished: (i) Fossa della Pernice, less peralkaline and (ii) Balata dei Turchi–Salto la Vecchia, distinctly more peralkaline and having almost identical c…
Burial dissolution of micrite in Middle East carbonate reservoirs (Jurassic–Cretaceous): keys for recognition and timing.
2006
14 pages; International audience; This paper discusses burial diagenesis and especially a burial dissolution phase and its effects on micrite microtexture in reservoirs in the Middle East. Three microporous reservoirs were selected: the Cenomanian Mishrif Formation in Iraq; the Kimmeridgian–Tithonian Arab D and the Barremian Kharaib Formations, both in Abu Dhabi. Staining, cathodoluminescence and scanning electron microscopy were used for petrographic observations. In the selected reservoirs, three typical micrite microtextures are distinguished: micro-rhombic, compact anhedral, and rounded. The chronology of diagenesis, based on petrographic observations, shows that mineralogical stabilisa…
Bulk carbonate isotope stratigraphy from CRP-3 core (Victoria Land Basin, Antarctica): evidence for Eocene–Oligocene palaeoclimatic evolution
2005
Bulk carbonate isotope compositions and carbonate petrography from upper Eocene and lower Oligocene siliciclastic sediments of the CRP-3 sediment core (Victoria Land Basin, Antarctica) have been investigated with the aim of contributing to reconstruction of the Antarctic Cenozoic palaeoclimate. Most of the carbonate is calcite cement occurring as patches, nodules and horizons and consisting of equant and/or drusy sparry calcite, pervasive blocky calcite and rare poikilotopic calcite spar. 18O-depleted values (from −17 to −8 δ‰) of the CRP-3 carbonates suggest that the precipitating fluids were a mixing between marine and meteoric waters from melting glaciers. The δ18O record exhibits a numb…