Search results for "feature"

Melt extraction and accumulation from partially molten rocks

2004

Current models for melt segregation and ascent are not adequate to accurately describe transport and accumulation in combination. We propose that transport is discontinuous and in batches, and that accumulation occurs by stepwise merging of batches. A simple numerical model of jostling spheres that merge when they touch was used to represent stepwise accumulation and transport of batches by propagation of hydrofractures. Results of the numerical model indicate that such a system may quickly develop into a self-organised critical (SOC) state. In this state, the distribution of melt batch volumes can be described by a power law, with an exponent m that lies between 2/3 and 1. Once a self-orga…

Polycyclic Aromatic Hydrocarbons (PAH) in Volcano island (Aeolian archipelago) mud utilized for therapeutic purpose

2007

This paper examines the possible presence, distribution, nature and sources of 18 Polycyclic Aromatic Hydrocarbons (PAH) as constituents of the mud pools collected in Vulcano Aeolian Island. PAH are important from environmental and toxicological point of view. Analysis was performed by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM). The total concentration of Polycyclic Aromatic Hydrocarbons ranged from 112 to 154 μ g/Kg of dry matrix. The volcanic mud, used for therapeutic purposes, are moderately contaminated.

Improvement of the technological process of carbonated spring water by implementing the quality and food safety management standards

2019

Bottled spring water must be health providing, clean, without microorganisms, parasites or substances. The design, manufacturing and management of processes, related to spring water bottling involves controlling the safety issues that may arise in the production processes. These aspects are not sufficient to prevent hazards and they must be related to the implementation of a quality and food safety systems. The aim of the paper is to improve the technological process of carbonated spring water in Monopolis S.A Company, by implementing the quality and food safety management standards. The methodology is based on the implementation requirements of the HACCP principles, included in ISO 22000 s…

Late Proterozoic and Silurian basement units within the Serbo-Macedonian Massif, northern Greece: the significance of terrane accretion in the Hellen…

2006

Os isotopes and highly siderophile elements (HSE) in the Ligurian Ophiolites, Italy.

2000

The Os isotopic and highly siderophile element (HSE) concentration systematics of the upper mantle have been the focus of much recent interest. However, little systematic study has addressed the combined HSE and Os isotopes in mantle rocks from MOR ophiolites. The Ligurian ophiolites in northern Italy represent an important class of ophiolites representing, like Zabargad or the Galicia margin, crust with clear ocean ridge affinity floored by older mantle with arguably more continental affinities [Rampone et al., J. Petrol. 36, 18–105, 1995; Rampone et al., Contrib. Mineral. Petrol. 123, 61–67, 1996]. We have studied a suite of 15 geochemically and geologically well characterized mantle peri…

Internal structures and dating of complex zircons from Meissen Massif monzonites, Saxony

1999

Abstract U–Pb zircon ages were determined for accessory zircons from two monzonites from the Meissen Massif (Northern Bohemian Massif, Germany) by SHRIMP ion microprobe. BSE and CL imaging revealed that the monzonite zircons, showing oscillatory growth zoning, often contain inherited cores. Raman microprobe measurements showed that zoned rims (U 277–1426 ppm, Th 144–910 ppm) are slightly disordered to moderately metamict whereas cores have a wide spectrum of structural states, from well-crystallized to highly metamict. The radionuclide (U+Th) content of cores varies from a few hundred to more than 20,000 ppm. SHRIMP ion probe measurements on zoned rims, interpreted as zircon growth during c…

Zircon reconnaissance dating of Proterozoic gneisses along the Kunene River of northwestern Namibia

2015

Abstract The northern margin of the Epupa Metamorphic Complex (EMC) along the Kunene River in NW Namibia is one of the geologically least known terranes in Africa because of its remoteness and difficult accessibility. We report field relationships and reconnaissance zircon ages for granitoid gneisses from a 120 km foot-traverse along the Kunene River between the Ruacana Falls in the east and Marienfluss in the west. Most rocks are late Palaeoproterozoic in age and correlate well with similar rocks of the EMC farther south in Kaokoland (1757–1835 Ma, one sample 1861 Ma) and with granitoid rocks in the Kamanjab Inlier, some 400 km SE of the Kunene River (1801–1836 Ma). All these rocks constit…

Toward resourcefulness: Pathways for community positive health

2021

Abstract   Communities play a central role in strengthening their health, but conventional community health promotion often adopts paternalistic and top-down approaches. Conversely, agentic approaches are critiqued for tasking marginalized communities to create change without opportunities. Taking into consideration these shortcomings, we ask how communities may be most effectively and appropriately supported in their pursuit of health. We review community health literature to articulate how community health is understood, moving from negative to positive conceptions; determined, moving from a risk-factor orientation to social determination; and promoted, moving from conventional to agentic…

On the formation of maars

1973

The Pleistocene maars in the Eifel region of Germany, and Massif Central in France, formed when fissures opened at the bottom of older valleys allowing stream water to pour down them and come into contact with rising magma. The resulting phreato-magmatic eruptions gave rise to both base surge and air-fall deposits. Spalling of wall rock at depth enlarged the fissure into an eruption chamber. Subsidence along a ring fault into the eruption chamber accounts for the larger crater cut into the country rocks. The volume relationship between the crater excavated, the ejected pyroclastic debris of the rim and the volume below the floor of the crater, indicates that the volume of the maar ejecta is…

Craton reactivation on the Labrador Sea margins: 40Ar/39Ar age and Sr–Nd–Hf–Pb isotope constraints from alkaline and carbonatite intrusives

2007

Abstract The once-contiguous North Atlantic craton (NAC) is crosscut by the Labrador Sea that opened during the Early Cenozoic after extensive Mesozoic continental rifting and removal of cratonic mantle. This large-scale structural change within the cratonic lithosphere was followed at about 150 Ma by the cessation of ultrapotassic and potassic-to-carbonatitic magma production, which had prevailed throughout much of the NAC history. At Aillik Bay, a sequence of olivine lamproites (1374.2 ± 4.2 Ma, 2σ), aillikites/carbonatites (590–555 Ma), and nephelinites (141.6 ± 1.0 Ma, 2σ) erupted through the southern NAC edge on the present-day Labrador Sea margin. Links between these alkaline magma ty…