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1.
Sacit Özdemir Cahit Yeşilyaprak Bahadır Aktuğ Derya Öztürk Deniz Çoker Recep Balbay 《Experimental Astronomy》2018,46(2):323-336
We present preliminary statistics on the precipitable water vapor (PWV) content over the Karakaya Hills in Erzurum city, where the largest optical and near-infrared astronomical telescope in Turkey will be operated. Since the observatory will observe in the near-infrared (NIR), it is intended to perform PWV measurements of the atmosphere above the site by using signal delays in Global Positioning System (GPS) communication. The analysis of the GPS data recorded on the summit for almost one year shows that the atmosphere over the site of the observatory, which has an altitude of 3170 m, has favorable conditions for NIR observations. From GPS measurements, we report that the site had an average PWV of 3.2 mm and a median PWV of 2.7 mm between October 6, 2016, and June 15, 2017. We also present the time dependency of the PWV content and the correlations between the amount of PWV and the other meteorological records gathered from radiosonde flights and ground-based measurements. 相似文献
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Volkan Karabacak
nder Ynlü Eray Dkü Nafiye Güne K&#x;yak Erhan Altunel ükrü
züdoru Cahit alar Yal&#x;ner Hüsnü Serdar Akyüz 《Geoarchaeology》2013,28(6):531-543
The ancient city of Kibyra in southwest Turkey has the potential to reveal the location and date of historical earthquakes. The most compelling evidence for earthquake faulting is observed in the city's Roman stadium. Damage related to seismic shaking is characterized by systematically collapsed columns, dilated and collapsed walls, and by rotated and displaced blocks in the stadium. Detailed archaeoseismological observations suggest that Kibyra was affected by earthquakes that were also recorded in historical earthquake catalogs. Although there is no historical record of a large earthquake after the 5th century A.D., Optically stimulated luminescence (OSL) dating of deposits under the collapsed blocks suggests a later seismic event. OSL results indicate that another large event occurred in southwest Turkey, probably around the 10–11th century A.D., and caused extensive damage (Io = VIII‐IX) to the Kibyra stadium. 相似文献
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Cüneyt Akal Cahit Helvacı Dejan Prelević Paul van den Bogaard 《International Journal of Earth Sciences》2013,102(2):435-453
Volcanic rocks of the Afyon province (eastern part of western Anatolia) make up a multistage potassic and ultrapotassic alkaline series dated from 14 to 12 Ma. The early-stage Si-oversaturated volcanic rocks around the Afyon city and further southward are trachyandesitic volcanic activity (14.23 ± 0.09 Ma). Late-stage Si-undersaturated volcanism in the southernmost part of the Afyon volcanic province took place in three episodes inferred from their stratigraphic relationships and ages. Melilite–leucitites (11.50 ± 0.03 Ma), spotted trachyandesites, tephryphonolites and lamproites (11.91 ± 0.13 Ma) formed in the first episode; trachyandesites in the second episode and finally phonotephrites, phonolite, basaltic trachyandesites and nosean-bearing trachyandesites during the last episode. The parameter Q [normative q-(ne + lc + kls + ol)] of western Anatolia volcanism clearly decreased southward with time becoming zero in the time interval 10–15 Ma. The magmatism experienced a sudden change in the extent of Si saturation after 14 Ma, during late-stage volcanic activity of Afyon volcanic province at around 12 Ma, though there was some coexistence of Si-oversaturated and Si-undersaturated magmas during the whole life of Afyon volcanic province. 相似文献
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Volkan Karabacak
nder Ynlü Eray Dkü Nafiye Günen K&#x;yak Erhan Altunel ükrü
züdoru Cahit alar Yal&#x;ner Hüsnü Serdar Akyüz 《Geoarchaeology》2014,29(4):353-356
In their comment, Elitez and Yaltırak (2013) criticize our paper (Karabacak et al. 2013 ) by arguing that it contains misinterpretations and unreliable data for a fault cutting the Roman Stadium in the ancient city of Kibyra. However their comments are not based on strong arguments to disprove our geological and archeological field observations or previous data. Here we present additional data supported by new figures which validate the faulting both in the bedrock and in the stadium floor. We reject their comments and uphold our original viewpoint on the faulting at the Stadium. 相似文献
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Yal??n?E.?ErsoyEmail author Cahit?Helvac? Martin?R.?Palmer 《Contributions to Mineralogy and Petrology》2012,163(3):379-401
The western Anatolian volcanic province formed during Eocene to Recent times is one of the major volcanic belts in the Aegean–western
Anatolian region. We present new chemical (whole-rock major and trace elements, and Sr, Nd, Pb and O isotopes) and new Ar/Ar
age data from the Miocene volcanic rocks in the NE–SW-trending Neogene basins that formed on the northern part of the Menderes
Massif during its exhumation as a core complex. The early-middle Miocene volcanic rocks are classified as high-K calc-alkaline
(HKVR), shoshonitic (SHVR) and ultrapotassic (UKVR), with the Late Miocene basalts being transitional between the early-middle
Miocene volcanics and the Na-alkaline Quaternary Kula volcanics (QKV). The early-middle Miocene volcanic rocks are strongly
enriched in large ion lithophile elements (LILE), have high 87Sr/86Sr(i) (0.70631–0.71001), low 143Nd/144Nd(i) (0.512145–0.512488) and high Pb isotope ratios (206Pb/204Pb = 18.838–19.148; 207Pb/204Pb = 15.672–15.725; 208Pb/204Pb = 38.904–39.172). The high field strength element (HFSE) ratios of the most primitive early-middle Miocene volcanic rocks
indicate that they were derived from a mantle source with a primitive mantle (PM)-like composition. The HFSE ratios of the
late Miocene basalts and QKV, on the other hand, indicate an OIB-like mantle origin—a hypothesis that is supported by their
trace element patterns and isotopic compositions. The HFSE ratios of the early-middle Miocene volcanic rocks also indicate
that their mantle source was distinct from those of the Eocene volcanic rocks located further north, and of the other volcanic
provinces in the region. The mantle source of the SHVR and UKVR was influenced by (1) trace element and isotopic enrichment
by subduction-related metasomatic events and (2) trace element enrichment by “multi-stage melting and melt percolation” processes
in the lithospheric mantle. The contemporaneous SHVR and UKVR show little effect of upper crustal contamination. Trace element
ratios of the HKVR indicate that they were derived mainly from lower continental crustal melts which then mixed with mantle-derived
lavas (~20–40%). The HKVR then underwent differentiation from andesites to rhyolites via nearly pure fractional crystallization
processes in the upper crust, such that have undergone a two-stage petrogenetic evolution. 相似文献
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Tectonic implications of new Appalachian Ultradeep Core Hole (ADCOH) seismic reflection data from the crystalline southern Appalachians 总被引：1，自引：0，他引：1
Robert D. Hatcher Jr. John K. Costain Cahit Conih Robert A. Phinney Richard T. Williams 《Geophysical Journal International》1987,89(1):157-162
Summary. Some 180 km of new VIBROSEIS profiles have been acquired in the southern Appalachian Inner Piedmont, Brevard fault zone and eastern Blue Ridge as part of the ADCOH Project site investigation. These data are of the highest quality yet obtained in a crystalline terrane in the US, perhaps in the world, and reveal several conclusions that should have a direct bearing upon the world-wide nature of composite crystalline thrust sheets and their modes of interaction with the platform rocks beneath. Strong reflections previously interpreted as the base of the crystalline sheet are clearly part of the platform sedimentary (clastic rocks) sequence resting upon the autochthonous basement and early Palaeozoic rift basins. This reflection package and related transparent zones are clearly repeated beneath the crystalline sheet indicating a complex of thrusts repeating units within the platform succession. Reflectors (granitoid-amplibolite contacts) in the crystalline sheet in the Inner Piedmont represent recumbent folds of similar wavelengths and amplitudes to folds mappable on the surface. Duplexing of platform rocks beneath the crystalline sheet appears to have resulted in doming of the crystalline sheet. Similarly, duplex formation in the platform was probably controlled by both the thickness of the crystalline sheet and the rheological properties of the platform succession. 相似文献
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Samuel T. Peavy Cahit oruh John K. Costain William J. Domoracki 《Journal of Geodynamics》2004,37(3-5):633
Two reflection seismic transects, one across the central Appalachians in Virginia and the other across the southern Appalachians in Georgia, reveal a significant contrast in mid- and lower crustal reflectivity from east to west. Data from east of the Blue Ridge geologic province in Virginia and to the east of the Inner Piedmont in Georgia show a highly reflective crust extending from the near-surface to the Moho, including zones of east-dipping reflections, a sub-horizontal reflection signature at 7 seconds, and a west-dipping Moho. Reflection seismic data from west of the Blue Ridge in Virginia and Inner Piedmont farther south are characterized by reflector geometries related to deformation above a master decollement, leading to classic ‘thin-skinned’ tectonic structures in the overlying allochthon, and few if any apparent structures in the underlying basement. The location of the Iapetan rifted margin, the preexistence of favorably oriented structures to the east of this point, and sub-horizontal weak zones within the lower Paleozoic shelf strata have played critical roles in the distribution of seismic reflector geometry. Seismic reflection signatures seen in the southeastern United States are a result of multiple episodes of deformation from the early Paleozoic through the middle Mesozoic. Oblique stresses during late Paleozoic time produced transpression that manifested itself as predominantly strike-slip faulting to the east of the Blue Ridge/Inner Piedmont. Onlapping lower Paleozoic shelf strata responded to tectonic stresses through thin-skinned deformation above a master decollement during the late Paleozoic Alleghanian orogeny, aided in part by sub-horizontal zones of weakness in the strata. This partitioning of strain was supported via tectonic buttressing provided by Precambrian continental crust that was little deformed in the Taconic orogeny. During the Alleghanian orogeny, the variations in Valley and Ridge deformational style between the central and southern Appalachians were controlled by the original shape of the continental edge. Further deformation during Mesozoic extension occurred to the east of the Precambrian rift margin in the region where favorably oriented faults were reactivated, leading to the rotation of the fault zones from more steeply dipping initial orientations, the merging of the mid-crustal reflection zone with the Moho, and the formation of Mesozoic basins and antiformal reflections in the seismic sections. 相似文献
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