Van Yüzüncü Yıl Üniversitesi

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Morphosedimentary Evidences of Lake Level Variations in the Terraces of Lake Van (Turkey)
(Association Francaise pour l'Etude du Quaternaire, 2010) Christol, A.; Kuzucuoglu, C.; Fort, M.; Mouralis, D.; Dogu, A.F.; Akköprü, E.; Zorer, H.
In the eastern Anatolian Mountains, the relatively high-magnitude variations exhibited by the level of Lake Van in recent years indicate, as the lake has no outlet, that this level can be considered as a sensitive indicator of climate if these variations respond to changes in water input/output. Until now, previous palaeoclimatic research has focused mainly on deep sediments in the lake, which provided an environmental sequence which is today a reference for the Late Glacial and the Holocene in the Middle East. In spite of many landforms and deposits around the lake pointing out to the occurrence of very high levels in the past, studies on the lacustrine sediments preserved in terrace records around the lake have remained quite rare since a first exhaustive overview realized in the 1970's. We here present the first results of a field work coupled with sedimentology studies (stratigraphy, facies analyses), DGPS elevation measurements, spatialized reconstructions. Chronostratigraphy takes advantage of the presence of interstratified tephras layers dated by 39Ar/40Ar, of travertines dated by U-Th series, as well as of organic deposits and shells dated by 14C. Results evidence the occurrence of two major and rapid transgressions, the first one happening at the beginning of the Last Glacial, the second one in the millennia preceding the Last Glacial Maximum (LGM). Each identified lacustrine cycle started with a very rapid transgression followed by slower regressions with intermediate oscillations. Regressions started immediately after the highest stand was reached (+80 m and +55 m). Regressions lasted long, with some stand-by during the descent, allowing erosion surfaces to truncate the surface of the emerging lake deposits. During Upper Pleistocene, tectonic and volcanic activities interfered with the climatic record of lake levels, both by deforming deposits locally (uplift, faulting) and by modifying the drainage area and river network of the lake basin (closure by damming, captures, isolation). Our preliminary results thus enlighten the complexity of the processes triggering the high magnitude transgressions of the Upper Pleistocene Van Lake, as well as the difficulty to establish correspondences between climatic changes and water volume changes as evidenced by past shoreline deposits preserved in the terrace sedimentary records.
Obsidian Outcrops From Nemrut Volcano (Eastern Anatolia): Evidence in Favor of an Exploitable Source, First Results
(Groupe Francias Geomorphologie, 2015) Robin, Anne-Kyria; Mouralis, Damase; Kuzucuoglu, Catherine; Akkopru, Ebru; Gratuze, Bernard; Dogu, Ali Fuat; Cetoute, Joel
Archeological studies have demonstrated that many Prehistoric artefacts in obsidian found in the Near East have a chemical affinity with obsidian out-cropping in the Nemrut volcano. In the archaeological literature, Mount Nemrut is considered as one of the most important obsidian sources used by prehistoric societies. During our two field works in 2013 and 2014, we prospected a wide area on and around Nemrut volcano. Our findings confirm the location of the obsidian outcrops described in the literature. According to our observation, obsidian on Mount Nemrut volcano is generally not exploitable for chopping tools. Most of the studied obsidians we defined on the field, present a facies with numerous phenocrysts and cracks, which is not compatible with a good knapping quality. However, we identified a new outcrop associated with obsidian artefacts such as nuclei and rough flakes. Geological samples of the obsidian from this outcrop present all a very different fades compare to those of others Mount Nemrut obsidians: obsidian from this area does not show any phenocryst or cracks, and they are very homogeneous and uniform. These characteristics are in favor to knapping criteria. Comparatively to the other known obsidian outcrops in the Nemrut volcano, we can assume here that this obsidian outcrop is, to date, the only source one that could have been exploited, by Prehistoric people on the Nemrut volcano. Our work, using chemical analyzes (LA-ICP-MS), petrology and field observation enhances characteristics for workable obsidian that depends on the modality of emplacement. This last one should have been different from the other outcrops to provide a different facies.
The Pyroclastites Around Southwestern Part of Van Lake (Eatern Anatolia, Turquey): Implications on The Regional Palaeohydrography
(Soc Geologique France, 2010) Mouralis, Damase; Kuzucuoglu, Catherine; Akkopru, Ebbru; Dogu, Ali Fuat; Scaillet, Stephane; Christol, Aurelien; Guillou, Herve
THE PYROCLASTITES AROUND SOUTHWESTERN PART OF VAN LAKE (EATERN ANATOLIA, TURQUEY): IMPLICATIONS ON THE REGIONAL PALAEOHYDROGRAPHY Located in eastern Anatolia (Turkey), Lake Van is the fourth largest lake in the world. Along the banks of the lake, several lake terraces record Pleistocene variations of the lake levels. In the terraces, the lake deposits are often interbedded with pyroclastites emitted by the volcanoes located on the northern side of the lake. Our research focuses on the south-western part of the lake, where several pyroclastites interbedded with lake deposits allow establishing a regional tephrostratigraphy, which is being Ar/Ar dated. In this area, the study of the pyroclastites allows to understand the impact of volcanism on the palaeohydrography: all the valleys where filled-in with pyroclastites which induced heavy disruptions of the drainage network. Moreover, our research enlightens evidences that volcanic activity was responsible for the enclosure of the lake and that the major transgression of the lake, dated ca. 100 ka, is not only linked to changes in the water balance, but at first linked to volcanic activity.
Symptomatic Os Triangulare. (Case Report)
(Masson Editeur, 1999) Akpinar, F; Aydinlioglu, A; Tosun, N
Os triangulare is an accessory bone found in the triangular cartilage of the wrist just distal to the end of the ulna and is generally asymptomatic. A case report of symptomatic Os triangulare is reported. Treatment associated immobilization and anti-inflammatory medication.
Total Bilateral Carpal Coalition With Carpometacarpal Fusion: One Case
(Masson Editeur, 2001) Tuncay, I; Akpinar, F; Unal, O; Aydinlioglu, A
Carpal coalition may involve more than two carpal bones wich is more common when coalition occurs as part of a syndrome of congenital malformations. We describe an unusual case of congenital complete entire carpal coalition with massive carpometacarpal coalition except the first carpometacarpal joint and abnormal distal radioulnar joint bilaterally. In addition, radiocarpal joint surfaces were slightly irregular but compatible. There were abnormal distal radioulnar joints and ulnar styloids articulated with the ulnar side of the lunate of the both wrists.

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