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The Origin of the Gran Canarian Xenoliths / Ursprunget till Gran Canarias xenoliterJägerup, Beatrice January 2016 (has links)
Xenoliths are pieces from the surrounding bedrock, brought to the surface of the earth by host magma. On Gran Canaria, the largest island in the Canary Islands archipelago, strange xenoliths have been found. They are light in color, porous and very different from the basaltic magma carrying them. By studying petrological features and oxygen isotope content of the xenoliths, the focus of this report will be to investigate their origin. The minerals and texture of 14 samples were studied in thin section, and the δ18O–value was determined for 17 samples. The mineralogical composition of xenolith glass was examined by EPMa. The results show that the xenoliths are rich in silica rich glass, quartz and feldspars, but also have high calcium content. 9 of 14 xenoliths have textures and δ18O–values from 8.1 ‰ to 16.77 ‰, similar to sedimentary rocks. The remaining xenoliths are metamorphosed and exhibit altered phenocrysts, indicating they have been melted and recrystallized. The latter group also has extremely low δ18O–value, which could be explained by the effects of hydrothermal processes. Most likely all the xenoliths originate from the prevolcanic sedimentary deposits beneath Gran Canaria.
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Ceramic thin-section analysis and Early Postclassic to Middle Postclassic discontinuity at Colha, BelizeReid, Elizabeth Katherine 12 November 2013 (has links)
Petrographic and Type:variety analyses of Colha ceramics are used to investigate changes in ceramic production technology and organization during the Early and Middle Postclassic. Postclassic sherds from Colha are grouped by petrofabric, surface treatment, and modes. This dissertation focuses on the petrofabric analysis of the ceramic sherds. The groupings are then compared to locally available raw materials. Changes in technological homogeneity, production specialization, and origin will be examined and related to the general economy of Postclassic Colha. / text
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Sicilian amphorae (1st-6th centuries AD) : typology, production and tradeFranco, Carmela January 2014 (has links)
This thesis is a comprehensive investigation of the transport containers produced in Roman Sicily over a chronological period composed of five phases: Early Roman period (30 BC–AD 100); Middle Roman period (AD 100–300); Late Roman period (AD 300–440); Vandal Perios (AD 440/535) and Early Byzantine period (AD 536/600). The research investigates the production and transportation of Sicilian foodstuffs (especially wine) from the major ports of the island to Mediterranean ports and northern Europe. The results demonstrate the wide distribution of Sicilian amphorae and their important role within the wider economy of the Roman Empire. The importance of this research lies in the fact that, despite the agricultural prosperity of Sicily in the Roman Period and its strategic topographical position, transport amphorae remain understudied especially in economic terms. In regards to typology, chronology and distribution, our current knowledge of regional containers has not reached a level comparable to that of amphorae manufactured in other territories. The key discussion focuses on the commercial dynamics of Roman Sicilian amphorae from local, regional and Mediterranean-wide perspectives. The research aims to outline the distribution trends of Sicilian amphorae, looking at the different relative quantities of each amphora type and consequently the extent to which they are present in regions inside and outside Sicily, while considering presences and absences within the more general and homogeneous context of the Mediterranean basin. The organisation of Sicilian amphora production is also tackled through the presentation of probable production sites and excavated kilns. Using these examples, the study investigates the management of production of these containers on the island. The initial data obtained by this research represents a first step in determining differences between Sicilian amphorae workshops producing amphorae — therefore trading wine — for Mediterranean export and manufacturing sites specializing in local/regional trade. Other key achievements include the creation of a new illustrated typology with profile drawings of all the amphora forms and a summary and catalogue of Sicilian amphorae fabrics. In the thesis, the results of archaeometric analysis (thin-sections) carried out on more than 120 Sicilian amphora samples, provided by numerous institutions in Sicily and abroad, are presented. These results add significantly to our knowledge of the fabric composition, manufacture technology, origin and consequently movement of these amphorae around the Mediterranean over six centuries. More generally the research shows that the study of Sicilian material culture along with archaeological evidence is essential for recording the economic dynamics of Sicily, with the intent of dispelling the stereotype that Sicily's primary role was as a grain supplier to Rome. Besides grain — widely produced and exported throughout the imperial period, as attested by ancient sources and inscriptions — the archaeological evidence clearly indicates the export of foodstuffs, especially wine, at an inter-provincial level from the 1<sup>st</sup> until the second half of the 6<sup>th</sup> century AD.
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Deep anthropogenic topsoils in Scotland : a geoarchaeological and historical investigation into distribution, character and conservation under modern land coverMcKenzie, Joanne T. January 2006 (has links)
Deep anthropogenic topsoils – those augmented through long-term additions of mineral bulk among fertilising agents – retain in both their physical and chemical make-up significant indicators for cultural activity. This project researched the geographical distribution and historical context of deep anthropogenic topsoils in Scotland and the Isles, and used this information to investigate the impact of current land cover upon the cultural information they retain. In so doing, the project investigated the potential for conservation of this significant cultural resource. A review of the historical information available on agricultural and manuring practices for Scotland identified several factors likely to affect deep topsoil distribution and frequency. These were: the availability of bulk manures to Scottish farmers, the significance of the seaweed resource in determining fertiliser strategies in coastal areas, and the influence of urban settlement and associated patterns of domestic and industrial waste disposal on the location of deep topsoils. Evidence for widespread deep topsoil development was limited. The primary data source used – the First Statistical Account of Scotland – was manipulated into a spatial database in ArcView GIS, to which geographical data from the Soil Survey of Scotland and national archaeological survey databases were added. This was used to devise a survey programme aiming both to investigate the potential factors affecting soil development listed above, and to locate deep topsoil sites for analysis. Three sites were identified with deep topsoils under different cover types (woodland, arable and pasture). The urban-influenced context of two of these highlighted the significance of urban settlement to the location of Scottish deep topsoils. Analysis of pH, organic matter, and total phosphorus content showed a correlation between raised organic matter and a corresponding increase in phosphorus content in soils under permanent vegetation. By contrast, soils under arable cultivation showed no such rise. This was attributed to the action of cropping in removing modern organic inputs prior to down-profile cycling. The potential for pasture and woodland cover to affect relict soil signatures was therefore observed. Thin section analysis aimed to both provide micromorphological characterisation of the three deep topsoil sites and investigate the effect of modern land cover on micromorphological indicators. Distinctive differences in micromorphological character were observed between the rural and urban deep topsoils, with the latter showing a strong focus on carbonised fuel residues and industrial wastes. All sites showed a highly individual micromorphological character, reflective of localised fertilising systems. There was no correlation between land cover type and survival of material indictors for anthropogenic activity, with soil cultural indicators surviving well, particularly those characteristic of urban-influenced topsoils. Suggestions for preservation strategies for this potentially rare and highly localised cultural resource included the incorporation of deep anthropogenic topsoil conservation into current government policy relating to care of the rural historic environment, and the improvement of data on the resource through ongoing survey and excavation.
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