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21.
Dr.-Ing. Hikmet Akin 《International Journal of Earth Sciences》1979,68(1):253-283
Zusammenfassung Die Erkenntnisse über den tektonischen Aufbau, die geologische Entwicklung und die Genese der Lagerstätten, sowie über die petrologischen Eigenschaften der Magmatite führen zu der Auffassung, daß das Ostpontische Gebirge (Nordost-Türkei) insgesamt ein (Paläo-)Inselbogensystem darstellt. Daraus folgt die Annahme, daß die südlich benachbarten Anatoliden in der Vortiefenzone dieses Vulkanbogens gebildet wurden. Das Schwarze Meer ist dann entsprechend der Theorie der Plattentektonik als ein aktives Randbecken nördlich des Inselbogens anzusehen; seine kontinentale Kruste wurde in den mittleren Bereichen in ozeanische Kruste (in situ) umgewandelt.Die mit den sauren Vulkaniten zusammen auftretenden Buntmetall-Lagerstätten sind dem Kuroko-Typ im weiteren Sinn zuzuordnen; sie sind die charakteristischen Lagerstätten der Ostpontiden. Dagegen sind Porphyrische Kupferlagerstätten von wirtschaftlicher Bedeutung aufgrund dieses Konzepts kaum zu erwarten.
Herrn o. Prof. Dr.-Ing. A. Wilke zum 65. Geburtstag gewidmet! 相似文献
Present knowledge about the tectonical structure, geological development, genesis of ore deposits as well as about petrological characteristics of magmatites supports the concept of an (paleo) island arc system for the Eastern Pontic Mountains (NE Turkey). Consequently, the Anatolides in the southern neighbourhood would have been formed within the foredeep of that volcanic arc. According to the theory of plate tectonics the Black Sea is to be considered as an active marginal basin north of the island arc, its continental crust in the central zone being transformed (in situ) into oceanic crust.The base metal ore deposits associated with acid volcanics can be classified as Kuroko types, these are the characteristic ore deposits of the Eastern Pontides, Economic porphyry copper ore deposits, however, would hardly be expected according to this concept.
Résumé Les acquisitions sur les structures tectoniques, le développement géologique et la génèse des gisements, de même que sur les propriétés pétrologiques des magmatites permettent d'interpréter génétiquement les Montagnes Pontiques Orientales comme un système de (paléo) arc insularie. En conséquence on peut considérer que les Anatolides, qui les avoisinent au sud, se sont formées dans l'avant — fosse de cet arc volcanique. La Mer Noire peut être donc considérée — selon la théorie de la »tectonique des plagues« — commé un bassin marginal actif au Nord de l'arc insulaire, so croûte continentale étant transformée dans la zone centrale (in situ) en croûte océanique.Les gisements des métaux non-ferreux associés avec les volcanites acides peuvent être rapportés aux types »Kuroko« (sensu lato), représentant les minéralisations caractéristiques pour les Pontides Orientales. Quant aux gisements type »Porphyry Copper«, il n'y a guère de chance, selon notre hypothèse, pour qu'il en existe avec une importance économique.
, , , - (- ) . , . , , ; in situ . , , «Kypoko» . . - «» .
Herrn o. Prof. Dr.-Ing. A. Wilke zum 65. Geburtstag gewidmet! 相似文献
22.
Liquefaction which is one of the most destructive ground deformations occurs during an earthquake in saturated or partially saturated silty and sandy soils, which may cause serious damages such as settlement and tilting of structures due to shear strength loss of soils. Standard (SPT) and cone (CPT) penetration tests as well as the shear wave velocity (V s)-based methods are commonly used for the determination of liquefaction potential. In this research, it was aimed to compare the SPT and V s-based liquefaction analysis methods by generating different earthquake scenarios. Accordingly, the Erci? residential area, which was mostly affected by the 2011 Van earthquake (M w = 7.1), was chosen as the model site. Erci? (Van, Turkey) and its surroundings settle on an alluvial plain which consists of silty and sandy layers with shallow groundwater level. Moreover, Çald?ran, Erci?–Kocap?nar and Van Fault Zones are the major seismic sources of the region which have a significant potential of producing large magnitude earthquakes. After liquefaction assessments, the liquefaction potential in the western part of the region and in the coastal regions nearby the Lake Van is found to be higher than the other locations. Thus, it can be stated that the soil tightness and groundwater level dominantly control the liquefaction potential. In addition, the lateral spreading and sand boiling spots observed after the 23rd October 2011 Van earthquake overlap the scenario boundaries predicted in this study. Eventually, the use of V s-based liquefaction analysis in collaboration with the SPT results is quite advantageous to assess the rate of liquefaction in a specific area. 相似文献
23.
The Palaeoproterozoic Frere Formation (ca 1.89 Gyr old) of the Earaheedy Basin, Western Australia, is a ca 600 m thick succession of iron formation and fine‐grained, clastic sedimentary rocks that accumulated on an unrimmed continental margin with oceanic upwelling. Lithofacies stacking patterns suggest that deposition occurred during a marine transgression punctuated by higher frequency relative sea‐level fluctuations that produced five parasequences. Decametre‐scale parasequences are defined by flooding surfaces overlain by either laminated magnetite or magnetite‐bearing, hummocky cross‐stratified sandstone that grades upward into interbedded hematite‐rich mudstone and trough cross‐stratified granular iron formation. Each aggradational cycle is interpreted to record progradation of intertidal and tidal channel sediments over shallow subtidal and storm‐generated deposits of the middle shelf. The presence of aeolian deposits, mud cracks and absence of coarse clastics indicate deposition along an arid coastline with significant wind‐blown sediment input. Iron formation in the Frere Formation, in contrast to most other Palaeoproterozoic examples, was deposited almost exclusively in peritidal environments. These other continental margin iron formations also reflect upwelling of anoxic, Fe‐rich sea water, but accumulated in the full spectrum of shelf environments. Dilution by fine‐grained, windblown terrigenous clastic sediment probably prevented the Frere iron formation from forming in deeper settings. Lithofacies associations and interpreted paragenetic pathways of Fe‐rich lithofacies further suggest precipitation in sea water with a prominent oxygen chemocline. Although essentially unmetamorphosed, the complex diagenetic history of the Frere Formation demonstrates that understanding the alteration of iron formation is a prerequisite for any investigation seeking to interpret ocean‐atmosphere evolution. Unlike studies that focus exclusively on their chemistry, an approach that also considers palaeoenvironment and oceanography, as well the effects of post‐depositional fluid flow and alteration, mitigates the potential for incorrectly interpreting geochemical data. 相似文献
24.
The present study to find seasonal (September 2010–June 2011) heavy metal (Cd, Pb, Cr, Co, Ni, Zn, Cu, Fe, As) contamination and the origins thereof in surface sediments of Gökçekaya Dam Lake, as constructed on Sakarya River, the third-longest river in Turkey and the largest river of the Northwestern Anatolia. Upon analyses for the purpose thereof, heavy metal contamination in annual average concentrations in the lake sediment varied, respectively, as Fe > Zn > Cr > Ni > Cu > Pb > Co > As > Cd. Statistical assessments performed in order to see whether the average values of the heavy metal contamination as measured at stations placed in the lake changed by seasonal periods. There found statistically significant differences especially in Cd, Zn, and Pb between seasonal periods. In accordance with the Sediment Quality Index, Gökçekaya Dam Lake sediment was classified as “highly polluted” in terms of the amount of anthropogenic contaminants of As, Cr, Cu, Ni, Pb, and Zn. Enrichment factor and geoaccumulation index values (I geo) were calculated in order to geochemically interpret the source of contamination due to heavy metal concentration in the lake sediment and the level of pollution. The As, Co, Cr, Cu, Ni Pb, and Zn values demonstrated that the sediment was rich for anthropogenic contaminants. The lake was found especially rich for arsenic (14.97–34.70 mg/kg) and lead (68.75–98.65 mg/kg) in accordance with annual average values. In general the lake was geochemically characterized as “moderately contaminated” in terms of As, Co, Cr, Cu, Ni, Pb, and Zn content. 相似文献
25.
The transition region and coronal explorer 总被引：5，自引：0，他引：5
Handy B.N. Acton L.W. Kankelborg C.C. Wolfson C.J. Akin D.J. Bruner M.E. Caravalho R. Catura R.C. Chevalier R. Duncan D.W. Edwards C.G. Feinstein C.N. Freeland S.L. Friedlaender F.M. Hoffmann C.H. Hurlburt N.E. Jurcevich B.K. Katz N.L. Kelly G.A. Lemen J.R. Levay M. Lindgren R.W. Mathur D.P. Meyer S.B. Morrison S.J. Morrison M.D. Nightingale R.W. Pope T.P. Rehse R.A. Schrijver C.J. Shine R.A. Shing L. Strong K.T. Tarbell T.D. Title A.M. Torgerson D.D. Golub L. Bookbinder J.A. Caldwell D. Cheimets P.N. Davis W.N. Deluca E.E. McMullen R.A. Warren H.P. Amato D. Fisher R. Maldonado H. Parkinson C. 《Solar physics》1999,187(2):229-260
The Transition Region and Coronal Explorer (TRACE) satellite, launched 2 April 1998, is a NASA Small Explorer (SMEX) that
images the solar photosphere, transition region and corona with unprecedented spatial resolution and temporal continuity.
To provide continuous coverage of solar phenomena, TRACE is located in a sun-synchronous polar orbit. The ∼700 Mbytes of data
which are collected daily are made available for unrestricted use within a few days of observation. The instrument features
a 30-cm Cassegrain telescope with a field of view of 8.5×.5 arc min and a spatial resolution of 1 arc sec (0.5 arc sec pixels).
TRACE contains multilayer optics and a lumogen-coated CCD detector to record three EUV wavelengths and several UV wavelengths.
It observes plasmas at selected temperatures from 6000 K to 10 MK with a typical temporal resolution of less than 1 min. 相似文献
26.
Beril Akin 《洁净——土壤、空气、水》2008,36(4):360-365
The production of excess sludge is one of the most serious challenges in biological wastewater treatment. In the present work, disintegration is added as a new additional unit operation in a wastewater treatment plant, and the main objective is to reduce the amount of excess sludge. The use of high power ultrasound can effectively disintegrate the bacterial cells, and thereby, enhance the subsequent biodegradation during digestion. In the study, attempts are made to determine the disintegration capacity of waste activated sludge that has different total solids (TS) concentrations with low ultrasound frequency (20 kHz) and a fixed amplitude value (50%). The results show that in terms of soluble chemical oxygen demand (SCOD) release, sludge disintegration was primarily governed by ultrasonic density (W mL–1), whereas specific energy input appears to be more critical for protein release. A SCOD release of about 329 mg SCOD gTS–1 was obtained at a TS content of 2% and specific energy input of 5 kWs gTS–1. The SCOD release decreased to 248.5 and 124.2 mgSCOD gTS–1 at TS contents of 4 and 6%, respectively. The highest protein release of 80.7 mg gTS–1 was obtained at a TS content of 2% and a specific energy input of 10 kWs g–1. The sludge disintegration efficiency declined significantly at higher TS content. 相似文献
27.
28.
This paper describes different change detection techniques, including image differencing, image rationing, image regression and change vector analysis (CVA) to assess their effectiveness for detecting land use/cover change in a Mediterranean environment. Three Landsat TM scenes recorded on 7 July 1985, 27 July 1993 and 21 July 2005 were used to minimize change detection error introduced by seasonal differences. Images were geometrically, atmospherically and radiometrically corrected. The four change detection techniques were applied and an object-based supervised classification was used as a crossclassification to determine ‘from–to’ change which enabled assessment of the four techniques. The change vector analysis resulted in the largest overall accuracy of 75.25 and 75.55% for the 1985–1993 and 1993–2005 image pairs, respectively. The ratio yielded the least accurate results with an overall accuracy of 59.10 and 61.05% for the 1985–1993 and 1993–2005 image pairs, respectively. Different change detection algorithms have their own merits and advantages. However, the change vector analysis change detection technique was the most accurate model for handling the variability present in Mediterranean land use/cover. 相似文献
29.
Spatial and temporal variation in fish assemblage structure of Koycegiz Lagoon–Estuarine System (KLES), located on the northwestern Turkish coast of Mediterranean, was investigated along an estuarine gradient where salinity ranged from 5 in upper reaches to 40 in lower reaches during October 1993–September 1994. Throughout the study, 42 species, consisting of marine (25), marine–estuarine-dependent (12), freshwater (3), catadromous (1), and estuarine resident (1) forms, were collected in trammel nets. Although species richness of marine species was greater than that of other groups, numerical contribution by marine species to the total catch was only 16%. Tilapia spp., the most abundant species mostly during summer and early spring at upper reaches, contributed 17% of the total samples. Among the seven species of Mugilidae, which contributed 42% of the total catch, Mugil cephalus, Liza aurata, and Liza salines contributed 10, 13, and 10% of the total catch, respectively. Consistent with findings from other studies, species richness and abundance were highest during late spring and summer and the lowest during winter and early spring. Samples from sites at or near the sea had more marine species. Samples from upper reaches had more freshwater and marine–estuarine-dependent species. Canonical correspondence analysis (CCA) indicated that salinity and turbidity were the most important environmental parameters affecting fishes. Sites near the sea were associated with high salinity and low turbidity, and sites in upper reaches had low salinity and high turbidity. Thus, the pattern observed in fish assemblage structure appears to be strongly influenced by species' responses to dominant salinity and turbidity gradients. 相似文献
30.
Assessment of rockfall hazard around Afyon Castle,Turkey 总被引：2，自引：0，他引：2
The Afyon Castle is a tourist destination and a historical site in the City of Afyon in Turkey. The Castle is located on a
steep hill, with a height of 226 m. In close proximity to the Castle there are settlements. The hill consists of trachitic
andesite. The rock contains columnar joints and flow layering. Owing to these discontinuities, blocks of varying sizes had
fallen down. The settlement areas near the Castle are now in danger because of the rockfall risk. In this study, rockfall
analysis was carried out along nine profiles of the hill. Fall-out distance, bounce height, kinetic energy and velocity of
the rocks along each profile were investigated. The results of the analyses were evaluated, and the areas delineated as susceptible
to rockfall risk are highlighted. Remedial measures including rock bolts and protective fences were suggested on the basis
of the field observations and the rockfall risk evaluation. 相似文献