Abstract:

Dolines and uvalas which are characteristic landform of karstic areas displays intensive development in Taurus Karstic Zone In this study, dolines and uvalas on karstic plateau located at southwest of Tahtalı Mountains (Central Taurus), on borderline between Kayseri-Adana were investigated. Totally 992 karstic dissolution pits including 846 dolines and 146 uvalas have been identified on karstic plateau as result of investigation of 1/25000 scale topographic map. Center X and Y coordinates, elevation (m), area (m2), perimeter (m), long and short axis length (m), azimuth of long axis (º), ratio of long axis to short axis, density, circularity and nearest neighbor index values of each pit are calculated by GIS. By examining relationships among obtained data, factors controlling development of doline and uvalas were attempted to reveal. Most of the forms are found on Upper Cretase limestone at between 2200 to 2350 meters. Areas of the forms vary between 16 m2 - 230000 m2, while their maximum length changes between 192 - 816 meters. Mean density of the forms is 22 pit/km2 while maximum density of them is reach to 46 depression/km2. Circularity index and long/short axis ratios of dolines show that depressions don’t have an important elliptical shape and they protect their circularity characteristics. Also nearest neighbour index and value of nearest distance indicate that distribution of the forms is random. This situation arises from absence of a tectonic factor affecting doline distribution on plateau surface. But rose diagrams show that long axis of the dolines extend along NE-SW direction in parallel with the general direction of extension of mountains. Also it indicates that there is a significant relationship between long axis of the uvalas and lineaments obtained from satellite images and paleovalley axis. These relationships display that karstic dissolution start with the gaps between the inclined layer surfaces and continue following paleovalley axis.

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