Trace Element Levels in the Groundwater of Mediterranean Coastal Plains – The Case of Silifke,Turkey     

Turan Yilmaz  Galip Seckin  Bulent Sari 《洁净——土壤、空气、水》2010,38(3):221-224

The Silifke plain is located near the coast of the Mediterranean Sea in Turkey. The delta in the plain is a highly fertile land that supports the agriculture of more than twenty types of crop. Some trace element content of the groundwater samples taken from the existing wells in this area are analyzed using inductively coupled plasma optical emission spectrometry (ICP‐OES). The mean levels (ppm) of boron (B), barium (Ba), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn), total chromium (TCr), cadmium (Cd), copper (Cu), aluminum (Al), and nickel (Ni) were obtained for the sampling points in the area for four seasons. Groundwater samples taken in the study area don't exhibit significantly elevated levels of these elements during a period of twelve months between December 2007 and November 2008. Furthermore, all of the elements exhibit values lower than 0.005 ppm, with the exception of B, Ba, and Fe. The results demonstrate that although these three elements produce the highest values, most are found to be appropriate for activities such as irrigation and human consumption in terms of trace elements.  相似文献   

The sources of metal contents in the shelf sediments from the Marmara Sea, Turkey     

Oya Algan  Nuray Balkıs  M. Namık Çağatay  Erol Sarı 《Environmental Geology》2004,46(6-7):932-950

The shelf area is the largest morphological unit of the Marmara Sea and is subjected to increasing population, urbanization, and industrial activities. Metal contents (Al, Fe, Mn, Cu, Pb, Zn, Ni, Cr, Co and Hg) of the surface sediments from the shelf areas of the Marmara Sea generally do not indicate shelf-wide pollution. The variability of the metal contents of the shelf sediments is mainly governed by the geochemical differences in the northern and southern hinterlands. Northern shelf sediments contain lower values compared to those of the southern shelf, where higher Ni, Cr, Pb, Cu and Zn are derived from the rock formations and mineralized zones. However, besides from the natural high background in the southern shelf, some anthropogenic influences are evident from EF values of Pb, Zn and Cu, and also from their high mobility in the semi-isolated bay sediments. Anthropogenic influences are found to be limited at the confluence of Istanbul Strait in the northern shelf. However, suspended sediments along the shallow parts of the northern shelf were found to be enriched in Pb and Hg and to a lesser degree in Zn, reflecting anthropogenic inputs from Istanbul Metropolitan and possibly from the Black Sea via the Istanbul Strait.  相似文献   

Impulsive and Varying Injection in Gamma-Ray Burst Afterglows     

Sari R  Mészáros P 《The Astrophysical journal》2000,535(1):L33-L37

The standard model of gamma-ray burst afterglows is based on synchrotron radiation from a blast wave produced when the relativistic ejecta encounters the surrounding medium. We reanalyze the refreshed shock scenario, in which slower material catches up with the decelerating ejecta and reenergizes it. This energization can be done either continuously or in discrete episodes. We show that such a scenario has two important implications. First, there is an additional component coming from the reverse shock that goes into the energizing ejecta. This persists for as long as the reenergization itself, which could extend for up to days or longer. We find that during this time the overall spectral peak is found at the characteristic frequency of the reverse shock. Second, if the injection is continuous, the dynamics will be different from that in constant energy evolution and will cause a slower decline of the observed fluxes. A simple test of the continuously refreshed scenario is that it predicts a spectral maximum in the far-infrared or millimeter range after a few days.  相似文献   

Petrological and geochemical evolution of the Kymi stock, a topaz granite cupola within the Wiborg rapakivi batholith, Finland   总被引：5，自引：0，他引：5  

Ilmari Haapala  Sari Lukkari 《Lithos》2005,80(1-4):347-362

The 6×3 km Kymi monzogranite stock represents the apical part of an epizonal late-stage pluton that was emplaced within the 1.65 to 1.63 Ga Wiborg rapakivi batholith. The stock has a well-developed zonal structure, from the rim to the center: stockscheider pegmatite, equigranular topaz granite, porphyritic topaz granite. The contact between the two granites is usually gradational within a few centimeters, but local inclusions of the porphyritic granite in the equigranular granite indicate that the latter solidified later. Hydrothermal greisen and quartz veins, some of which contain genthelvite, beryl, wolframite, cassiterite, and sulfides, cut the granites of the stock and the surrounding country rocks. The equigranular granite contains 1 to 4 vol.% topaz, and its biotite is lithian siderophyllite; the porphyritic granite has 0 to 3 vol.% topaz, and the mica is siderophyllite. The equigranular granite is geochemically highly evolved with elevated Li, Rb, Ga, Ta, and F, and very low Ba, Sr, Ti, and Zr. The REE patterns show deep negative Eu anomalies and tetrad effects indicating extreme magmatic fractionation and aqueous fluid–rock interaction. The zonal structure of the stock is interpreted as a result of differentiation within the magma chamber. Internal convection in the crystallizing magma chamber and upward flow of residual melt as a boundary layer along sloping contacts resulted in accumulation of a layer of highly evolved, volatile-rich magma in the apical part of the chamber. Crystallization of this apical magma produced the stockscheider pegmatite and the equigranular granite; the underlying crystal mush solidified as the porphyritic granite. Much of the crystallization took place from volatile-saturated melt, and episodic voluminous degassing expelled fluids into opened fractures where they or their derivatives reacted with country rocks and caused alteration and mineralization.  相似文献   

Secondary toppling failure analysis and optimal support design for ignimbrites in the Ihlara Valley (Cappadocia,Turkey) by finite element method (FEM)     

Sari  Mehmet 《Geotechnical and Geological Engineering》2021,39(7):5135-5160

Geotechnical and Geological Engineering - Kizilkaya ignimbrite, characterized by a blocky structure in the Ihlara Valley (Cappadocia, Turkey), poses many hazards to visitors and the human-made...  相似文献   

Seismic landslide analysis: Gurpinar (Istanbul) as a case history   总被引：2，自引：2，他引：0  

Ferhat Ozcep  Engin Erol  Fatih Saraçoğlu  Mustafa Haliloğlu 《Environmental Earth Sciences》2012,66(6):1617-1630

Slope failures triggered by earthquakes are among the most important soil mechanics problems. In this study, static and pseudostatic analyses of slope stability for earthquake conditions were carried out in the Gurpinar area. In situ testing (SPT) was carried out and laboratory samples were obtained from six boreholes (maximum depth 50.0 m) to determine soil classification and strength characteristics. Geophysical studies (seismic refraction and MASW) were also carried out in the area to estimate the structure and stiffness strength characteristics of the slope to 50.0 m depth. All field and laboratory data were used to determine the mechanical and structural (geometrical) behavior of the slope. In order to solve the slope stability problem, three soil slope models were considered. Pseudostatic analysis was carried out to estimate the earthquake acceleration seismic hazard in the region. These analyses showed that, while there was no potential slope instability under static load conditions, some problems would appear with increasing earthquake acceleration. A geotechnical slope improvement project is proposed for the study area.  相似文献   

Chemical and genetic characterization of the ungrouped pallasite Lieksa     

Emily M. Chiappe  Richard D. Ash  Arto Luttinen  Sari Lukkari  Jukka Kuva  Connor D. Hilton  Richard J. Walker 《Meteoritics & planetary science》2023,58(12):1747-1759

The meteorite Lieksa was found in 2017 in Löpönvaara, Finland, and later donated to the Finnish Museum of Natural History. Here, we report siderophile element concentrations, genetic isotopic data, and a metal–silicate segregation age for the meteorite. The ~280 g Lieksa is ~80% metal and ~20% silicate and oxide inclusions by volume, with the inclusions consisting primarily of Fe-rich olivine. Due to Lieksa's silicate content, coupled with a texture characterized by metal enclosing the silicates, it has been classified as a pallasite. Lieksa's olivine and bulk chemical characteristics are distinct from those of the known pallasite and iron meteorite groups, consistent with its classification as ungrouped. The meteorite exhibits a flat, chondrite-normalized highly siderophile element pattern, consistent with an origin as an early crystallization product from a metallic melt with chondritic relative abundances. Molybdenum, Ru, and ¹⁸³W isotopic data indicate that Lieksa formed in the non-carbonaceous (NC) domain of the solar nebula. Radiogenic ¹⁸²W abundances for Lieksa yield a model metal–silicate segregation age of 1.5 ± 0.8 Myr after calcium-aluminum-rich inclusion formation, which is within the range established for other NC-type pallasite and iron meteorite parent bodies.  相似文献