Mineralogical and Chemical Characteristics of Clay Areas,Gümüşhane Region (NE Turkey), and Their Detection Using the Crósta Technique with Landsat 7 and 8 Images

Natural Resources Research - The clay areas in Gümü?hane (NE Turkey) were examined in mineralogical and geochemical terms, and by remote sensing methods. X-ray diffraction, scanning...     

Geochemistry of dacitic volcanics in the Eastern Pontides (NE Turkey)

Dacitic rocks that crop out around the Zigana Mountain (Gümü?hane) in the eastern Pontide (NE Turkey), are mainly composed of quartz, plagioclase, sanidine, amphibole, muscovite, and biotite as the main minerals. Zircon and rutile are the accessory minerals. Pyrite, chalcopyrite, and covellite are the opaque components. On the basis of trace-element data, dacites have been classified as Dacite-I and Dacite-II. Dacite-I is tholeitic-transitional, whereas Dacite-II is transitional-calc-alkaline. The geochemical variation can be explained by the fractionation of the common mineral phases, such as plagioclase, hornblende, magnetite, and apatite. Dacites also show island-arc properties, with negative Nb, Sr, P, and Ti anomalies. The trace-element distrubitions of the dacitic rocks reflect the typical characteristics of rocks from the subduction-related tectonic setting, with enrichment of large-ion lithofile elements and light rare-earth element, but depletion in high-field-strength elements. The dacitic rocks are developed through plagioclase ± hornblende-controlled fractionation from the same parental magma that settled in two successive stages and are derived from an enriched source, probably by the mixing of slab-derived and lithospheric melts.     

Petrogenesis of the late Cretaceous Turnagoel intrusion in the eastern Pontides： Implications for magma genesis in the arc setting

A series of Cretaceous plutons is present in the eastern Pontides of northeastern Turkey.The Turnagl intrusion is the least studied and,thus,the least understood plutons in the orogen.This intrusion consists of hornblende-biotite granodiorites emplaced at 78 Ma based on LA-ICP-MS U-Pb zircon dating.It is of sub- alkaline affinity,belongs to the medium- to high-K calc-alkaline series,and displays features typical of Itype granites.The rocks of the intrusion are enriched in large-ion lithophile elements and light rare earthelements with negative Eu anomalies（Eu/Eu^*= 0.69-0.82）,but are deficient in high-field-strength elements.They have a small range of (⁸⁷Sr/⁸⁶Sr)_i（0.7060-0.7063）,ε_Ndi（-2.6 to -3.1）,and δ¹⁸O（+8.1 to +9.1） values.Their Pb isotopic ratios are ²⁰⁶Pb/²⁰⁴Pb = 18.63-18.65,²⁰⁷Pb/²⁰⁴Pb = 15.62-15.63,and ²⁰⁸Pb/²⁰⁴Pb = 38.53-38.55.The fractionation of plagioclase,hornblende,and Fe-Ti oxides had key functions in the evolution of the Tumagl intrusion.The crystallization temperatures of the melts ranged from 758 to 885℃ as determined by zircon and apatite saturation thermometry.All these characteristics,combined with the low values of K₂O/Na₂O and（Na₂O + K₂O）/（FeO^t+MgO + TiO₂）,as well as the high values of （CaO + FeO^t + MgO + TiO₂）.suggest an origin by dehydration melting from a metabasaltic lowercrustal source.     

Trace and rare earth elements as indicators of provenance and depositional environments of Lias cherts in Gumushane,NE Turkey

Trace elements and rare earth elements (REEs) of Lias-aged cherts in the Gumushane area were studied in order to understand their origin and depositional environment. Twenty three chert samples from five stratigraphic sections were analysed by inductively coupled plasma-mass spectrometry, X-ray diffraction, and mineralogical investigation. Lias cherts in the study area are microcrystalline, cryptocrystalline quartz, and megaquartz depending on mineralogical content. Trace elements of the cherts were compared with PAAS, Co, Y, and Th had stronger depletions in the five sections, whereas V, Ni, Zr, Nb, and Hf had smaller depletions. The distribution of Zr, Hf, and Ta yields Zr/Hf, Zr/Ta and Hf/Ta ratios (25/645, 37/665, and 0.18/3, respectively) that differ from those of chondrites and average upper continental crust, suggesting that these elements are likely non-detrital but are sourced from seawater. Th/U ratios range from 0.04 to 0.45 and are lower than those of the upper continental crust (average: 3.9). Lias-aged cherts have low total REE abundances and stronger depletions in five sections of the PAAS and chondrite-normalised plots. The cherts are characterised by a positive Eu anomaly (average: 4.9) and LREE-enrichment (La_N/Yb_N = average: 3.5). In addition, about one-half of the cherts exhibit positive Ce anomaly (range: 0.25–2.58), chondritic Y/Ho values (range: 3.3–60), and low (La/Ce)_N values (average: 1.8). REE and trace element abundance in Lias cherts indicate that these elements were likely derived from hydrothermal solutions, terrigenous sources, and seawater. The REE patterns of the cherts show that they were probably deposited close to a continental margin.     

VZ CVn: a close binary system with γ Doradus-like variations

We present new photometric two-colour observations of the double-lined close binary star VZ CVn. Combining two data sets obtained in 1971–72 and in 2006, the physical parameters of both components were derived. After removing the light variations due to the eclipses and proximity effects, a periodic variation in the more massive component with a dominant period of 1.068 76 d could be detected in the first photometric data set. In accordance with its position on the Hertzsprung–Russell diagram and both its pulsation period and pulsation constant of 0.62 d, the primary component of VZ CVn should be an excellent γ Doradus candidate. The less massive secondary component seems to have smaller radius with respect to its mass. Both components appear to have lower luminosities with respect to their masses; hence, their radiative properties seem to be different. The evolutionary status of the components is also discussed.     

Rehabilitation of storm water collection systems of urban environment using the small roads as conveyance channels

In this study a new grated inlet is proposed for small roads which do not have storm water collection systems. A setup was designed and constructed in the laboratory conditions to calibrate the grated inlet. The inlet is suggested to be installed at the end of the road where the road itself joins to another road or to a street. Thus, newly installed inlet will collaborate with existing storm water collecting system of the main road. Inlet structure covered by slots is installed across a 0.90-m wide flume which will act as a small road. The slots are longitudinal and parallel to the flow direction in order to curtail clogging. It is a tilting flume and both subcritical and supercritical flow regimes can be observed. The intercepted flow by the inlet is measured and the efficiency of the inlet is obtained in terms of longitudinal slope and the Froude number. It is observed that the grate efficiency gets higher as the longitudinal slope approaches to horizontal. Further the grate efficiency also depends on the total flow through the channel. As flow increases in the channel, the efficiency of the grate increases within the limit of the inlet or discharge channels capacity.     

Absolute properties of the neglected eclipsing B-type binary HD 194495

We present the results of the high-resolution spectroscopic observations of the neglected binary system HD 194495 (B3 IV-V+B4 V). A combined analysis of three different photometric data set (Tycho B_T and V_T photometry, H_p-band data of Hipparcos and V-band data of ASAS3 photometry) and radial velocities indicates that the system has an orbital period of 4.90494 ± 0.00005 days and an inclination of 69 ± 1 degrees. This solution yields masses and radii of M₁ = 7.57 ± 0.08 M_⊙ and R₁ = 5.82 ± 0.03 R_⊙ for the primary and M₂ = 5.46 ± 0.09 M_⊙ and R₂ = 3.14 ± 0.08 R_⊙ for the secondary. Based on the position of the two stars plotted on a theoretical H-R diagram, we find that the age of the system is ?28 Myr, according to stellar evolutionary models. The spectroscopic and photometric results are in agreement with those obtained using theoretical predictions.     

The irregular variable KU Her: The light and period variations

We present CCD photometric observations of the slow irregular type variable KU Her. We have also used observations from the ASAS Database and the AAVSO International Database. The V-band observations span eight years from August of 2002 to September of 2010. The length and density of the data enable us to look for variations on time scales ranging from days to years. The V-band observations of KU Her are analysed to derive periodicity. This analysis was an approach to find the fundamental periods of the variability of KU Her. Analysis of the KU Her light variation indicates a complex combination of different periods. Five main and three harmonic periods are identified. In addition to the period analysis, we present the colour variations of the star.