Search results for "Lithology"
showing 10 items of 61 documents
Gamma activity and geochemical features of building materials: estimation of gamma dose rate and indoor radon levels in Sicily.
2001
A high-purity germanium detector has been used to measure the abundance of radium (Ra), thorium (Th) and potassium (K) in building materials used in Sicilian dwellings. The measurements were performed to evaluate which material was suitable for the construction of an enclosure, which would have a low background emission. The materials examined in this work showed concentrations of 226Ra, 232Th and 40K dramatically variable depending on the lithologies, particularly in the case of blocks, sands and aggregates commonly used in building materials in Sicily. The results are discussed and a criterion is indicated to reduce the radiation dose to humans. Since radon inlet is a major health problem…
Seasonal variation of air kerma rate in Sicily.
2007
Thermoluminescence dosimetry has been used to measure air kerma in 29 sites in Sicily. Four three month measurement campaigns have been carried out in order to assess seasonal variations. Average annual values between 20 and 90 nGy h(-1), after cosmic background subtraction, are reported. Average annual values are strongly dependent on site lithology, and we find that winter data are generally the highest, while spring and autumn rates are generally the lowest with very similar trends in any site. Summer values generally lay in between. Largest seasonal variations are found in sites along the southern coast of the island, probably because of stronger action of winds affecting radon, along w…
Age and metasomatic alteration of the Mt Neill Granite at Nooldoonooldoona Waterhole, Mt Painter Inlier, South Australia
2001
Quartz feldspar augen gneisses, quartz augen schists and trondhjemites outcrop at Nooldoonooldoona Waterhole in the southwestern corner of the Proterozoic Mt Painter Inlier, northern Flinders Ranges, South Australia. These rocks were previously interpreted as having different origins and ages. However, we argue that all rock types were the result of deformation and strong metasomatic alteration of one common precursor: the Mt Neill Granite. Our conclusion is based on field observations that show that the different lithologies grade into each other and that intrusive contacts are lacking. Whole rock major and trace element analyses also point to a common protolith. Finally, Pb/Pb dating of m…
Trace elements in scalp hair of children chronically exposed to volcanic activity (Mt. Etna, Italy)
2014
Abstract The aim of this survey was to use scalp hair as a biomonitor to evaluate the environmental exposure to metals and metalloids of schoolchildren living around the Mt. Etna area, and to verify whether the degree of human exposure to trace elements is subject to changes in local environmental factors. Twenty trace elements were determined in 376 samples of scalp hair from schoolboys (11–13 years old) of both genders, living in ten towns located around the volcanic area of Mt. Etna (Sicily). The results were compared with those (215 samples) from children living in areas of Sicily characterized by a different geological setting (reference site). As, U and V showed much higher concentrat…
Diverse Lithologies and Alteration Events on the Rim of Noachian‐Aged Endeavour Crater, Meridiani Planum, Mars: In Situ Compositional Evidence
2018
We report the results of geological studies by the Opportunity Mars rover on the Endeavour Crater rim. Four major units occur in the region (oldest to youngest): the Matijevic, Shoemaker, Grasberg, and Burns formations. The Matijevic formation, consisting of fine‐grained clastic sediments, is the only pre‐Endeavour‐impact unit and might be part of the Noachian etched units of Meridiani Planum. The Shoemaker formation is a heterogeneous polymict impact breccia; its lowermost member incorporates material eroded from the underlying Matijevic formation. The Shoemaker formation is a close analog to the Bunte Breccia of the Ries Crater, although the average clast sizes are substantially larger in…
The “chessboard” classification scheme of mineral deposits: Mineralogy and geology from aluminum to zirconium
2010
Abstract Economic geology is a mixtum compositum of all geoscientific disciplines focused on one goal, finding new mineral depsosits and enhancing their exploitation. The keystones of this mixtum compositum are geology and mineralogy whose studies are centered around the emplacement of the ore body and the development of its minerals and rocks. In the present study, mineralogy and geology act as x - and y -coordinates of a classification chart of mineral resources called the “chessboard” (or “spreadsheet”) classification scheme. Magmatic and sedimentary lithologies together with tectonic structures (1 - D/pipes, 2 - D/veins) are plotted along the x -axis in the header of the spreadsheet dia…
Exploring the effect of absence selection on landslide susceptibility models: A case study in Sicily, Italy
2016
Abstract A statistical approach was employed to model the spatial distribution of rainfall-triggered landslides in two areas in Sicily (Italy) that occurred during the winter of 2004–2005. The investigated areas are located within the Belice River basin and extend for 38.5 and 10.3 km 2 , respectively. A landslide inventory was established for both areas using two Google Earth images taken on October 25th 2004 and on March 18th 2005, to map slope failures activated or reactivated during this interval. Geographic Information Systems (GIS) were used to prepare 5 m grids of the dependent variables (absence/presence of landslide) and independent variables (lithology and 13 DEM-derivatives). Mul…
Structural framework and crustal characteristics of the Sardinia Channel Alpine transect in the central Mediterranean
2000
Abstract The submerged area located between the Sardinia Channel and the western Sicily offshore has been investigated based on deep crustal and conventional seismic lines with the aim of illustrating the relationships between the crust and its overlying crystalline and sedimentary thrust wedge. Analyses of seismic attributes and reflector pattern, supported by dredge hauls, also provided data in areas where stratigraphic and lithologic control is absent. Crustal geometries, tectonic processes and timing of the deformation are discussed here. North of the Elimi chain (central Sardinia Channel) the reflecting body consists of superposed tectonic wedges of crystalline rocks and their Meso-Cen…
Palynology and lithostratigraphy of Late Elsterian to Early Saalian aquatic sediments in the Ziemupe–Jūrkalne area, western Latvia
2000
Abstract This study is based upon lithological and palynological investigation of test-drilling cores along the Baltic Sea coast. Three intertill units of basin sediments are underlain by a thin layer of Lētiža (Elsterian) till and overlain by glaciotectonically deformed Kurzeme (Saalian Complex) till. The Kurzeme till differs from the Lētiža till by higher contents of limestone clasts and rounded hornblende grains. The lowermost intertill unit consists of glaciolacustrine to glaciomarine laminated clay of the Sudrabi member, a late glacial deposit of the Lētiža glaciation. Treeless vegetation covered the adjoining land. Next is the marine to brackish Akme n rags formation, deposited during…
Chemical heterogeneities in the mantle: The equilibrium thermodynamic approach
2016
Abstract This study attempts to answer a simple and yet fundamental question in relation to our understanding of the chemical evolution of deep Earth and planetary interiors. Given two initially separate assemblages (lithologies) in chemical equilibrium can we predict the chemical and mineralogical compositions of the two assemblages when they are put together to form a new equilibrated system? Perhaps a common perception is that given sufficient time, the two assemblages will homogenize chemically and mineralogically, however from a chemical thermodynamic point of view, this is not the case. Certain petrological differences in terms of bulk composition, mineralogy and mineral abundance rem…