Characteristics,genesis and classification of a basin peat soil under negative human impact in Turkey     

Orhan Dengiz  H. Huseyin Ozaytekin  Gokhan Cayci  Abdullah Baran 《Environmental Geology》2009,56(6):1057-1063

The objective of this research was to investigate the morphology, genesis and classification of organic soils formed on depression and flat land around Lake Yenicaga, west-central Turkey. Formation of the area has been influenced by tectonic and karst processes. This peatland is important in this area due to its extensive use as a horticultural plant growth medium resulting from positive physical and chemical properties. Organic soils in the study area were formed in nutrient-rich conditions and it is classified as typical basin peat. Four representative pedons were excavated in the study area based on extensive observations performed with random grid method using an auger. Samples were taken from horizons in each profile for laboratory analyses. Organic matter contents ranged from 12.5 to 91.5% across all four pedons. Fiber contents were between 4.3 and 91.5%, and N ranged from 0.56 to 2.19%. Cation exchange capacity ranged from 37 to 222 cmol kg⁻¹, bulk density from 0.09 to 0.78 g cm⁻³, lime from 0.15 to 2.62%. The pH and EC_e values ranged from 5.38 to 7.92 and 0.50 to 3.80 dS m⁻¹, respectively. Sand, silt and clay contents of the organic soils ranged between 0.75–3.92, 40.70–74.77 and 24.15–57.30%, respectively. Differences in organic soils were found to depend on the environment, botanical origins, decomposition degrees, and groundwater composition. The organic soils of the research area were classified in the typic, hemic and hydric subgroups of Medifibrists (Soil Taxonomy 1999).  相似文献   

A view of tectonic structure and gravity anomalies of Hatay Region Southern Turkey using wavelet analysis     

Hakan Alp  A. Muhittin Albora Huseyin Tur 《Journal of Applied Geophysics》2011,75(3):498-505

In this study, we demonstrate wavelet analysis as a method of delineating the boundaries of subsurface geological structures. We applied wavelet transform to Bouguer anomaly data of the Cilicia Region and adjacent areas. The residual anomalies are the results of various depth and other properties of buried structures on the gravity anomaly map. The superposition of anomaly of the underground structures with different properties such as depth, density and size, increases the complexity of the overall system. Thus the extraction of the desired properties from the anomaly map becomes difficult. Different separation techniques are used to solve this problem. Wavelet transform is one of these modern approaches. Here, we tested various types of wavelet transform modeling on synthetic examples and then applied them to the gravity anomaly map of the Cilicia Region in Turkey. We have detected the borders of the Hatay Region in southern Turkey and proposed the tectonic model of this real complex structure using the wavelet transformation. The most important result we have found is the presence of a triple junction near the Hatay region.  相似文献   

The SFXC software correlator for very long baseline interferometry: algorithms and implementation     

A. Keimpema  M. M. Kettenis  S. V. Pogrebenko  R. M. Campbell  G. Cimó  D. A. Duev  B. Eldering  N. Kruithof  H. J. van Langevelde  D. Marchal  G. Molera Calvés  H. Ozdemir  Z. Paragi  Y. Pidopryhora  A. Szomoru  J. Yang 《Experimental Astronomy》2015,39(2):259-279

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Early Paleozoic Evolution of the NW Gondwanaland: Data from Southern Turkey and Surrounding Regions     

M. Cemal Goncuoglu  Huseyin Kozlu 《Gondwana Research》2000,3(3):315

The Lower Paleozoic rock-units in the Eastern Mediterranean can be separated into two distinct zones: the Northern Zone (Carpathian-Balkan, Istanbul, Zonguldak and Main Range terranes) and the Southern Zone (Tauride-Anatolide, SE Anatolian-Arabian, and Central Iranian terranes). A Gondwanan /Perigondwanan origin can only be properly indicated for the Southern Zone, whereas the Early Paleozoic paleogeographic positions of smaller terranes (e.g. Istanbul Terrane) of the Northern Zone remains questionable.During the Infracambrian-Early Cambrian time in the Southern Zone, the Pan-African consolidated NW Gondwanan pericratonic margin was rifted by back-arc extension or transtension, which is represented by the deposition of fault-controlled continental sediments.The late Early Cambrian-Late Cambrian period in the Southern Zone is designated by a regional transgression from northeast suggesting a rapid subsidence in the area to the northwest of Arabian-Tauride platform and hence opening of a relatively deep basin to the north.The Lower Ordovician in the Southern Zone comprising the Tremadoc and Arenig Series is characterized by a monotonous siliciclastic deposition. Towards the end of Early Ordovician shallowing upward sequences and formation of NW-SE trending highs were noticed. The stratigraphic hiatuses, unconformities and irregular distribution of the Caradoc-Ashgill deposits in the Southern Zone has been ascribed to glacio-eustatic sea-level changes.The Early Silurian (Aeronian-Telychian) deepening and deposition of black shales that follows the regression around the Ordovician-Silurian boundary in the Southern Zone is also very probably related to the relatively rapid global sea-level rise. To the north of the Tauride-Anatolide Platform, Wenlock and Late Silurian are represented by deep marine (basinal) sediments with oceanic basalts.The generation of an accretionary complex in the northern margin of the Taurides together with the regional regression in the southern Taurides and SE Anatolia at the uppermost Silurian-Lower Devonian boundary and the regional unconformity at Lower Devonian (Middle Lochkovian) is very probably related to the closure of a “Paleotethyan” oceanic basin to the north of the Perigondwanan terranes.  相似文献   

Adsorption of carbonate and bicarbonate salts at the air–brine interface     

Orhan Ozdemir  Stoyan I. Karakashev  Anh V. Nguyen  Jan D. Miller 《International Journal of Mineral Processing》2006

Previous research has shown that the flotation of soluble salt is determined by interfacial water structure, thermal stability, and viscosity. These salts include alkali halide and alkali oxyanion salts. Of particular interest are the carbonate salts such as those associated with the great trona deposit of the Green River basin in Wyoming. In this study, we investigated the adsorption of carbonate and bicarbonate salts at the air–brine interface and correlated the adsorption behavior with water structure. Specifically, the equilibrium and dynamic surface tensions of sodium carbonate and sodium bicarbonate salts have been measured as a function of the salt concentration up to saturation and compared with the model prediction using the Gibbs–Langmuir adsorption theory. The results show that the negative adsorption of sodium carbonate leads to a significant increase in surface tension of the brine solution. For sodium bicarbonate, both the negative adsorption and the increase in surface tension are significantly lower when compared with the sodium carbonate case. The negative adsorption is correlated with the water structure making/breaking character of carbonate and bicarbonate solutions. In particular, sodium ions are significantly more hydrated than carbonate and bicarbonate ions, and, therefore, tend to be excluded from the air–brine interface. On the other hand, carbonate and bicarbonate ions are accommodated at the air–brine interface. In any event, the balance between sodium exclusion and carbonate/bicarbonate accommodation results in an increase in the surface tension of these solutions with an increase in salt concentration.  相似文献   

A synthesis: Late Cenozoic stress field distribution at northeastern corner of the Eastern Mediterranean,SE Turkey     

Semir Over  Suha Ozden  Ulvi Can Unlugenc  Huseyin Yılmaz 《Comptes Rendus Geoscience》2004,336(1):93-103

Fault kinematic analysis and inversion of focal mechanisms of shallow earthquakes reveal significant evolution of the regional stress regime in the northeastern most corner of the Eastern Mediterranean region since the Mio-Pliocene to the present time. This study was carried out in the interaction area between the Arabian/African plates and the Anatolian block. The evolution of stress regimes consists of a change from older transpression to younger transtension. Both strike-slip stress regimes having a NNW- to northwest-trending σ_Hmax (σ₁) and ENE- to northeast-trending σ_Hmin (σ₃) axes induce a sinistral component of displacement on the major intra-continental Karatas–Osmaniye and Misis–Ceyhan faults elongated with the northeast-trending Misis Range between Adana and Osmaniye provinces (sub-area i) and by a NNE-trending plate boundary Amanos fault running along Amanos Range between Antakya and Kahramanmaras provinces (sub-area ii). The inversion results show that the transtensional stress regime is dominantly strike-slip to extension, with an ENE- to northeast-trending σ_Hmin (σ₃) axis for sub-areas (i) and (ii), respectively. The inversions of earthquake focal mechanisms indicate that the transtensional stress regime is still active in the whole study area since probably recent Quaternary time. To cite this article: S. Over et al., C. R. Geoscience 336 (2004).  相似文献   

Seismic technique to determine the allowable bearing pressure for shallow foundations in soils and rocks     

Semih S. Tezcan  Zuhal Ozdemir  Ali Keceli 《Acta Geophysica》2009,57(2):400-412

Based on a variety of case histories of site investigations, including extensive bore-hole data, laboratory testing and geophysical prospecting, an empirical formulation is proposed for the rapid determination of allowable bearing capacity of shallow foundations. The proposed expression consistently corroborates the results of the classical theory and is proven to be rapid and reliable. It consists of only two soil parameters, namely, the in situ measured shear wave velocity, and the unit weight. The unit weight may be also determined with sufficient accuracy by means of another empirical expression using the P-wave velocity. It is indicated that once the shear and P-wave velocities are measured in situ by an appropriate geophysical survey, the allowable bearing capacity as well as the coefficient of subgrade reaction and many other elasticity parameters may be determined rapidly and reliably through a single step operation, not only for soils, but also for rock formations. Such an innovative approach, using the seismic wave velocities only, is considerably cost- and time-saving in practice.  相似文献   

Effects of land-based sources on water quality in the Omerli reservoir (Istanbul,Turkey)     

Enis Morkoç  Vildan Tüfekçi  Huseyin Tüfekçi  Leyla Tolun  Fatma Telli Karakoç  Tuğba Güvensel 《Environmental Geology》2009,57(5):1035-1045

The Omerli reservoir is located on the northeastern side of the Istanbul City. It is one of the most important sources of drinking water with a surface area of 23.1 km² and a volume of 220 × 10⁶ m³ in the Marmara Region. Water quality characteristics of the lake investigated from May 2002 to April 2003 enabled us to identify the effect of waste loads on water quality of Omerli Lake. The following parameters were measured in the lake water: temperature (16.1°C), conductivity (250 μS/cm), secchi disk depth (1.9 m), dissolved oxygen (DO) (9.36 mg/L), nutrients [ortho-phosphate (78.9 μg/L), nitrate + nitrite (707.5 μg/L) and ammonia-nitrogen (264 μg/L)], chlorophyll a (9.43 μg/L), total organic carbon (3.33 mg/L), total suspended solids (4.54 mg/L), total poly aromatic hydrocarbon (t-PAH) (0.69 μg/L) and copper (24.5 μg/L). T-PAH (16.5 mg/g-dry-w), Cu (96.5 μg/g-dry-w), organic carbon (org-C) (2.0%) and N (0.44%) were determined in the surface sediment. The values of chlorophyll a and DO in the upper layer were relatively high and low secchi disk depths indicates eutrophic state. There are five channels discharging water, including waste water, into the lake. All channels were sampled during six occasions in order to cover variations between seasons. The following parameters were measured: total organic carbon, total phosphorus, total kjeldahl nitrogen, ammonia and total suspended solids with the flow rates. The Göçbeyli stream has the highest flow into the lake (1.5 × 10⁸ m³/year) but most of the nutrients were discharged from the Pa?aköy channel. It is accounting for 81% of ammonia and 80% of total phosphorus into the lake. Three scenarios were run using AQUATOX model: (1) all existing inflows are discharging into the lake (present situation); (2) none is discharging; (3) all are discharging except the Pa?aköy channel. The first scenario produced concentrations consistent with measurements in the lake. In all stations, a phytoplankton peak value was predicted during November and December 2002, and January 2003. In the second scenario, as expected, a significant decrease in the concentrations was predicted. In the third scenario, a small improvement in the water quality was obtained. To significantly improve the state of the lake, instead of entering Pa?aköy channel, wastewater should bypass the lake.  相似文献   

Early Archean spherule layers from the Barberton Greenstone Belt,South Africa: Mineralogy and geochemistry of the spherule beds in the CT3 drill core          下载免费PDF全文

Seda Ozdemir  Toni Schulz  Christian Koeberl  Wolf Uwe Reimold  Tanja Mohr‐Westheide  Desiree Hoehnel  Ralf Thomas Schmitt 《Meteoritics & planetary science》2017,52(12):2586-2631

Little is known about the Hadean and the Archean impact record on Earth. In the CT3 drill core from the Fig Tree Group of the northern Barberton Greenstone Belt, 17 spherule layer intersections occur, which, provide an outstanding new opportunity to gain insights into meteorite bombardment of the early Earth. CT3 spherules, as primary features, mostly exhibit textural patterns similar to those of the other Barberton spherule layers, but locally mineralogical and chemical compositional differences are observed, likely as a result of various degrees of alteration. The observed mineralogy of the spherule layers is of secondary origin and comprises K‐feldspar, phyllosilicates, carbonates, sulfides, and oxides, with the exception of secondary Ni‐Cr spinel that is of primary origin. Our petrographic investigations suggest alteration by K‐metasomatism, sericitization, silicification, and carbonatization. Siderophile element contents of bulk samples show significant enrichments in Ni (up to 2 wt%) and Ir (up to ~3 ppm), similar to previously studied Archean spherule layers. These values are indicative of the presence of a meteoritic component. On the other hand, lithophile and chalcophile element abundances indicate hydrothermal overprint on the CT3 samples; this may also have influenced the redistribution of the meteoritic component(s). Last, we group the CT3 spherule layers, which occur in three intervals (A, B, and C), according to their petrographic and geochemical features, which indicate evidence for at least three distinct impact events before tectonic overprint that affected the original deposits.  相似文献   

Predicting forest structural parameters using the image texture derived from WorldView-2 multispectral imagery in a dryland forest,Israel     

Ibrahim Ozdemir  Arnon Karnieli 《International Journal of Applied Earth Observation and Geoinformation》2011

Estimation of forest structural parameters by field-based data collection methods is both expensive and time consuming. Satellite remote sensing is a low-cost alternative in modeling and mapping structural parameters in large forest areas. The current study investigates the potential of using WordView-2 multispectral satellite imagery for predicting forest structural parameters in a dryland plantation forest in Israel. The relationships between image texture features and the several structural parameters such as Number of Trees (NT), Basal Area (BA), Stem Volume (SV), Clark-Evans Index (CEI), Diameter Differentiation Index (DDI), Contagion Index (CI), Gini Coefficient (GC), and Standard Deviation of Diameters at Breast Heights (SDDBH) were examined using correlation analyses. These variables were obtained from 30 m × 30 m square-shaped plots. The Standard Deviation of Gray Levels (SDGL) as a first order texture feature and the second order texture variables based on Gray Level Co-occurrence Matrix (GLCM) were calculated for the pixels that corresponds to field plots. The results of the correlation analysis indicate that the forest structural parameters are significantly correlated with the image texture features. The highest correlation coefficients were calculated for the relationships between the SDDBH and the contrast of red band (r = 0.75, p < 0.01), the BA and the entropy of blue band (r = 0.73, p < 0.01), and the GC and the contrast of blue band (r = 0.71, p < 0.01). Each forest structural parameter was modeled as a function of texture measures derived from the satellite image using stepwise multi linear regression analyses. The determination coefficient (R²) and root mean square error (RMSE) values of the best fitting models, respectively, are 0.38 and 109.56 ha⁻¹ for the NT; 0.54 and 1.79 m² ha⁻¹ for the BA; 0.42 and 27.18 m³ ha⁻¹ for the SV; 0.23 and 0.16 for the CEI; 0.32 and 0.05 for the DDI; 0.25 and 0.06 for the CI; 0.50 and 0.05 for the GC; and 0.67 and 0.70 for the SDDBH. The leave-one-out cross-validation technique was applied for validation of the best-fitted models (R² > 0.50). In conclusion, cross-validated statistics confirmed that the structural parameters including the BA, SDDBH, and GC can be predicted and mapped with a reasonable accuracy using the texture features extracted from the spectral bands of WorldView-2 image.  相似文献