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Öğe Causes of Darkening of the Pamukkale Travertines, Denizli, South-West Turkey(Parlar Scientific Publications (P S P), 2003) Zedef, Veysel; Matsuda, Yusuke; Tanaka, Yuji; Harada, Hisashi; Öncel, Mehmet Salim; Doyen, Adnan; Söğüt, Ali Rıza; Şensöğüt, CemSince the beginning of the 1990's, the travertines at Pamukkale, south-west Turkey, have faced a serious environmental pollution problem. The travertines were originally snow-white in colour, but this colour has been turning into pale grey. In addition to other features, the snow-white colour and the huge mass of rocks on the edge of Pamukkale plateau make the travertines unique and attractive to visitors. Living bacteria exist 1-2 mm beneath the surface of the travertines in both terrace and water channel types. The thickness of the bacterial lamina is 1-2 mm in the water channel type, whilst it is approximately 1 cm for other types. Absorbance Spectral (AS) data shows that the living bacteria are cyanobacteria, which are responsible for the green colour in certain areas of the travertines. Our investigations show that the major force responsible for the change of colour in the area is the increasing level of excess organic matter, which also causes a shift in the metal content of the travertines. While the greyish polluted samples have 584 ppm of Total Organic Carbon (TOC), the unpolluted snow-white samples have only 177 ppm of TOC. On the other hand, the Al, Fe and Mn contents of the polluted samples are respectively 144, 62, 6 ppm higher than the unpolluted samples. As the TOC is the main cause of the pollution, decreasing the organic matter in the pools would be the first step to protecting the area. This requires limiting, or even banning, people who enter the pools for swimming. Sources of Al, Fe, Mn and other hazardous metals should be reduced in the region.Öğe Effect of salt crystallization on stones of historical buildings and monuments, Konya, Central Turkey(PERGAMON-ELSEVIER SCIENCE LTD, 2007) Zedef, Veysel; Kocak, Kerim; Doyen, Adnan; Ozsen, Hakan; Kekec, BlIgehanIn this study, we investigated the chemical and physical properties of the volcanic rocks used as building stones in historical places and monuments. The chemical weathering effect of salt crystallization on these stones was measured on the laboratory conditions (in most cases, used samples were very small). For this purpose, the dry weight loss (DWL) test was conducted. The rocks of dacite, andesite and tuffs of volcanic origin have different durability against salt crystallization. The most stable rocks are dacites (DWL 2.06%) which were used in the construction of Hittite monuments at Eflatun. The durability of the stones is closely related to their chemical, mineralogical, petrographical and mechanical properties. The stones used in the historical buildings are generally much more stable than present-day building stones. (c) 2005 Elsevier Ltd. All rights reserved.Öğe Rare earth element (REE) geochemistry and genetic implications of the Mortas bauxite deposit (Seydisehir/Konya - Southern Turkey)(ELSEVIER GMBH, URBAN & FISCHER VERLAG, 2009) Karadag, M. Muzaffer; Kupeli, Suayip; Aryk, Fetullah; Ayhan, Ahmet; Zedef, Veysel; Doyen, AdnanThe Mediterranean-type karst-bauxite deposit of Mortas, South Turkey, placed unconformably between Cenomanian and Senonian shallow marine limestones is built of massive (MB), oolithic (OB), breccia-bearing (BB) and earthy (EB) bauxite horizons, from top to bottom. The MB layer is enriched in Al and REE (except Cc) due to loss of Si, Na, K, Mg and P. REE are accumulated in the BB but depleted in the EB layers. The ferruginous OB lost LREE and gained in HREE probable due to scavenging by authigenic heavy minerals like rutile, anatase and titanite. Total REE contents in the bauxite profile display an increasing trend from bottom to top, while negative and maximum positive Ce anomalies characterize the upper and the lower parts of the profile, respectively. This unusual REE behavior is explicable by assuming mobilization of Ce(W) either under reducing condition or chemical complexation under alkaline conditions in the top layer and scavenging of Cc by Al-Mg hydrosilicates and Ti-oxides and/or precipitation with authigenic REE minerals, especially of the bastnasite group near the bedrock limestones. Similarity in chondrite normalized-REE patterns of the Seydisehir phyllites, bauxite and terra rossa samples and the presence of tridymite (?) in bauxites makes a felsic source rock most likely and reveal a close genetic relationship between the Seydisehir phyllites and the recent terra rossa occurrences. The REE patterns of the bauxites resemble those of the Katrangedigi limestone despite variations in Sigma REE. Field observations and geochemical data together with mass-balance calculations suggest that the Mortas deposit was derived from the Seydisehir phyllites and argillic phase within the Katrangedigi limestone which in turn have Precambrian (?) felsic, probably granitic precursors. (c) 2008 Elsevier GmbH. All rights reserved.Öğe Stratigraphic Features of the Yesilova Ophiolite, Burdur, South-Western Turkey(SPRINGER INT PUBLISHING AG, 2014) Doyen, Adnan; Comlekciler, Fuat; Kocak, KerimThe Yesilova ophiolite is located in the Alpine zone as a major part of the Lycian nappes of western Taurus. It was formed at the southern branch of Neo-Tethys, and was abducted over the southern edge of the Menderes Massif during the Cenonian during Laramian orogenesis. The ophiolite in the study area starts with tectonite, consisting mainly of harzburgites (37.02 % MgO, 38.77 % SiO2, and 0.42 % Cr2O3) and smaller amounts of dunite and chromite pods. The sequence continues with cumulates, including (from bottom to top) dunite, wehrlite, clinopyroxenite, layered and nonlayered gabbro (45.53 % SiO2, 11.92 % Al2O3, and 13.11 % MgO), and plagiogranite (77.41 % SiO2, 0.25 % K2O). The tectonite and cumulates have been cut by isolated gabbro and diabase dikes. The altered volcanites are found at the top of ophiolitic sequence, and were abducted by the Upper Cretaceous Kizilcadag Melange, with limestone, chert-radiolarite blocks, and ophiolitic rock fragments. The upper Eocene Varsakyayla Formation rests over the melange; it contains abundant nummulites and is composed of conglomerate sandstone, limestone, and conglomerate towards the top. The stratigraphic sequence continues with the Pliocene-Quaternary Niyazlar Formation, consisting of terrigenous conglomerate intercalated with sandstone, and ends with rock talus and alluvium.
