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    Drainage Characteristics of the Cappadocia Region
    (Istanbul Univ, Fac Letters, Dept Geography, 2019) Ozturk, Muhammed Zeynel; Ozkan, Demet; Simsek, Mesut
    The morphology of the widespread badlands in the region of Cappadocia has mainly been the result of erosional processes on ignimbrite and tuff formations. Fairy chimneys are the most characteristic landforms of badlands morphology and many factors are responsible for the formation of these landforms in the region. Bedding, hardness and porosity of ignimbrites, shape, size and frequency of discontinuities in ignimbrites, slope, climate and drainage properties etc. of the area all significantly contribute to the development of badlands and fairy chimneys. In this study, drainage properties, which are one of the main controlling factors in this development, were investigated referencing 1/25.000 scale topography maps. Firstly, all valley thalwegs were digitized using GIS. Subsequently, the Strahler order numbers of each stream were determined, and a drainage density map was created. Basing our results on maximum drainage densities, the highest drainage density (15.3 km/km(2)) in the study area was identified in ignimbrite and tuffs in the Goreme National Park, whilst, the lowest drainage densities were located on plateau surfaces (basalt (9 km/km(2)), dacite (4.2 km/km(2)) and andesite (3.2 km/km(2)) in the southern part of the study area. According to the Strahler order method, 53% and 22.7% of all streams belong to first and second orders, respectively. All these results show that drainage conditions on ignimbrite and tuffs are determinant factors in the formation of both badlands morphology and fairy chimneys.
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    GIS based analysis of doline density on Taurus Mountains, Turkey
    (Springer, 2018) Ozturk, Muhammed Zeynel; Simsek, Mesut; Sener, Mehmet Furkan; Utlu, Mustafa
    The Taurus Mountain is one of the most important karstic region of the world and dolines are characteristics landforms of this area. However, the number and distribution of doline are unknown in the study area. The aims of this study are to explain the total number of dolines, distribution of doline density, effects of slope conditions and the change of doline orientation in the Taurus Mountains. According to the 1/25000 scale topographic maps utilized in this study, a total of 140,070 dolines were determined in a 13,189 km(2) area on eleven high karstic plateaus bordered by steep slopes and deep gorges. These plateaus are substantially affected by highly-faulted and jointed systems and about 80% of each plateau is covered with neritic limestone. The dolines are located at an elevation between 10 and 2870 m. Average elevation of all dolines is 1842 m. 90% of dolines are located between 1300 and 2270 m and only 5% of dolines found under 1330 m. According to this results, the densest doline zone corresponds to the alpine and periglacial zone above the treeline. Doline density reaches > 100 doline/km(2) on Mt. Anamas and the Seyran, Geyik and Akdag ranges as well as the TaAYeli plateau. Maximum density (187 doline/km(2)) is found on the Akdag Mountains. However, 66% of the study area is characterized by low density, 29.9% with moderate density, 3.4% with high density and 0.7% with very high density. The highest doline densities are seen on gentle slopes (15A degrees-25A degrees/km(2)) and steep slopes (> 35A degrees/km(2)) are limited doline distribution. According to the rose diagram formed by the azimuths of the long axis of the dolines at the Central Taurus, two direction are dominant in doline orientations (NW-SE and NE-SW). However, dominant directions are NE-SW at eastern, NE-SW and NW-SE at central and NW-SE at western part of the Central Taurus. According to this elongations, doline orientations are formed an arc which is formed by tectonic evolution of the Central Taurus.
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    Morphometric characteristics and paleogeographic implication of glacial cirques in Eastern Black Sea Mountains (Turkiye)
    (Elsevier, 2023) Simsek, Mesut; Ozturk, Muhammed Zeynel; Yesilyurt, Serdar; Utlu, Mustafa
    The Eastern Black Sea Mountains, located in the northeastern region of Anatolia and running parallel to the Black Sea coast, underwent glaciation during the Quaternary. The mountain range contains 811 cirque sites. Although the majority of the cirques are simple, 309 are complex, according to their developmental features. In Anatolia, intensive cirque development is observed only on north-facing slopes in several mountains, while in the Black Sea Mountains, 66.5 % of the cirques are located on north-facing slopes and 14.5 % on south-facing slopes. Differences in cirque morphometry between the north- and south-facing slopes were primarily influenced by aspect, which had a significant influence on Quaternary glaciation. While the northwest-facing cirques are the largest, the east- and southeast-facing cirques are the smallest. This situation is related to that air masses that bring rain to the mountains generally come from the northwest. The mean cirque floor elevation is 2815 m, while 90 % of the cirques have floor elevations between 2479 and 3130 m. In light of these measurements, the former Equilibrium Line Altitude (ELA), initially positioned above 2480 m, underwent a complete stabilization at elevations exceeding 2800 m within the Black Sea Mountains. However, these averages are not sufficient to represent the former ELA across the mountain. According to the cirque floor elevations, the cirques in the Nsector have a mean elevation of 2760 m, while the cirques in the S-sector have a mean elevation of 3004 m, and there is a 244 m difference between the two sectors. In the NW basin, the cirques start at 2434 m and reach a permanent former ELA level at 2743 m. In the SE basin, on the other hand, the cirques start at 2635 m and become permanent at 2920 m. Aspect had a significant effect on the distribution of other morphological elements associated with the cirques. The N-sector cirques harbor 73.5 % of the cirque lakes and 81.8 % of the rock glaciers. The average depth of the cirques in the northern sector stands at 388 m, whereas it diminishes to 341 m in the southern sector. Negative correlations emerge between former ELA levels and both latitude and distance from the watershed, while positive correlations align with distance from the coast. Based on these correlations and the associated distribution maps, a clear trend emerges: the former ELA diminishes as one travels north, approaches the coast, and encounters decreasing topographic elevations.
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    Morphometric Properties of Poljes in the Taurus Mountains, Southern Turkey
    (Istanbul Univ, Fac Letters, Dept Geography, 2021) Simsek, Mesut; Ozturk, Muhammed Zeynel; Dogan, Ugur; Utlu, Mustafa
    Poljes, which represents the largest and relatively the most complex karst forms, are one of the most characteristic and widespread features in the karst terrains of the Taurus Mountains. Although poljes have been one of the most studied landforms in the Anatolian karst, except for a few studies, no particular attention has been directed to provide a quantitative study on the morphometry and spatial distribution of poljes. In this study, an attempt has been made to present a comprehensive account of the basic morphometric characteristics and spatial distribution of the poljes within the karst regions in the Taurus karst belt, based on the critical review of the previous literature and detailed map studies. In this respect, 680 topographic maps, 1;25.000 scales with 10 m contour intervals, were analyzed and the 175 poljes were mapped. A data set based on the determination of morphometric parameters of the poljes was prepared, including X and Y centroid coordinates, the elevation of the floors above mean sea level, area, perimeter length, short and long axis lengths, elongation ratio, and circularity index. Within the scope of this dataset, the spatial distribution of the basic morphometric properties of poljes and the main factors controlling these properties were evaluated and interpreted. Most of the poljes in the Taurus karst belt are found in the area within the Isparta Angle located in the Western and Central Taurus. Most of the polje floor elevation (90%) is about between 447 and 1865 m above mean sea level though they are distributed in various elevations. Some poljes cover rather large areas, but the majority (65%) of them have a surface area of not more than 10 km sq. Due to the hydrological and tectonic characteristics of poljes, the circularity index values increase up to 28 and the elongation ratio values up to 9. The circularity index reaches higher values in fluvio-karst poljes dominated by fluvial processes, whereas the elongation ratio is higher in tectonically controlled poljes.
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    Morphotectonic development of surface karst in Western Taurus (Türkiye)
    (Springer, 2023) Sener, Mehmet Furkan; Simsek, Mesut; Utlu, Mustafa; Ozturk, Muhammed Zeynel; Sozbilir, Hasan
    The Taurus Mountains, the most important karst terrains of Turkiye, contain many surface and subsurface karst landforms, and the morphometric features of these landforms provide important data on the geomorphological and morphotectonic development of karst areas in the Taurus Mountains. Micro and macro karst depressions are the most important surface landforms in the Western Taurus Mountains. In this study, a total of 7093 micro depressions (doline) and 74 macro depressions (polje) located in the Western Taurus Mountains were detected and morphometric properties were calculated. The poljes developed within the Beydaglari Autochthon and Lycian nappes, while the dolines developed mainly in the high karst plateaus within the Beydaglari Autochthon. As briefly described below, the morphotectonic evolution of both landforms is closely related to the tectonic evolution of the Western Taurus Mountains. As a result of this tectonic activity, the Lycian Nappes from the northwest and the Antalya Nappes from the east thrust over the Beydaglari autochthon, leading to the development of nappes, reverse faults, and fold systems in the study area. The Western Taurus began terrestrialization starting from the Oligocene and began to erode from the Miocene. This erosion process led to the development of valley systems within the Western Taurus region. The NE-SW and NW-SE directional normal faults have developed under the influence of extensional tectonics since the Miocene. This extensional tectonism has caused widespread development of the poljes in the study area. Furthermore, with the lowering of the karst base level, dolines and paleovalleys began to develop in limestone areas at higher elevations. All morphometric and morphotectonic processes reveal that the extension of both doline and polje areas in the study area are parallel to the elongation of tectonic structures in the Western Taurus.
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    Structural controls on distribution of dolines on Mount Anamas (Taurus Mountains, Turkey)
    (Elsevier Science Bv, 2018) Ozturk, Muhammed Zeynel; Sener, Mehmet Furkan; Sener, Mehmet; Simsek, Mesut
    Solution dolines are characteristic landforms on the high plateaus of the Taurus Mountains. In this study, the effects of tectonic structures, drainage and slope conditions on the distribution and morphometric properties of dolines in the western part of the Central Taurus are explained. To delimit the dolines, 1/25000 scale topographic maps were used. The uppermost closed contour lines were digitized as polygons and the elevation, long and short axes, elongation ratios, orientation angles of the polygons were calculated. The doline density is compared with drainage density and mean slope values. A total of 111 rose diagrams were created in order to illustrate the superficial distribution of orientation. As a result, a total of 10,652 dolines were detected in a 711 km(2) doline area and maximum density reaches 123 dolines/km(2). However, according to the doline density, two distinct regions were detected, high density (RI) and low density (R2). Correlations between drainage density, slope angle and doline density are negative in the two regions. According to negative correlations, the drainage density is not a determinant factor in RI, while it is a determinant factor in R2. A 30 degrees slope angle (in km2) limits doline distribution on the plateau surface. The orientation of all doline long axes is NW-SE, which is parallel to the general orographic extent of Mount Anamas. However, different orientations were detected and these orientations were showed in farther sub-regions according to the 111 gridded rose diagrams. The overall result of this study is that the fault and joint systems that developed on the thick-bedded limestone between thrust faults affected the doline density, while lateral strike-slip, normal faults and joint systems in front of the thrust belt were more effective on the geometric shapes of dolines. (C) 2018 Elsevier B.V. All rights reserved.