Kapadokya Volkanik Provensi'nde Yer Alan Eğrem Tepe Hidrovolkanik Çökellerinin Petrolojik İncelemesi

Abstract

The existence of continually renewed lacustrine environments in the region represented by a continuous volcanic sequence together with lacustrine and fluvial sediments and mainly ignimbrite deposits is known in the Middle Miocene - Quaternary time interval in Cappadocia Volcanic Province (Central Anatolia). Hydrovolcanic eruptions and products that have occurred during geological time as a result of water – basic / intermediate magma interaction in the region where large lake / river environments develop, have not been encountered in previous studies. With this study, for the first time in Ürgüp region, hyaloclastites which occurs with the magma-water interaction were identified in confined areas. Resedimented deposits and volcaniclastites, which are thought to have formed in the same lake environment, are also identified in the region. Mineralogical and petrographic studies were carried out on the samples taken from the field, and mineral chemistries were determined by using Energy Dispersive Spectrometer (EDS). In addition, modern petrological analysis methods have been used with micro X-ray tomography device. Finally, the major oxides, trace elements and rare earth elements geochemicals of the products have been determined. One of the three distinguished units, Late Miocene aged, Ürgüp lacustrine resedimented deposits are in orange-brown colour, poor welded, poor sorted, grain supported, and contains 10-50 cm in diameter volcanic blocks. Also resedimented deposits are the most widespread units among the products that studied units. It is thought that Eğrem Hill hyaloclastites and Karain volcaniclastics are Pliocene aged. These two products are similar to each other in mineralogical, textural and geochemical aspects, although they can be seen at two locations 4 km apart. They are both gray in color, medium welded, poorly sorted and their matrix is carbonated. Also, vesicular rock fragments in the Karain volcaniclastics shows similar features to the Eğrem Hill juveniles. The resedimented deposits in the eastern part of Ürgüp are separated from other products, both in the stratigraphic location and in the rock fragments derived from a magma rich of incompatible trace elements. Eğrem Hill and Karain products are derived from geochemically similar magma origin. It is thought that large number of fault systems are responsible for the volcanic activities that generate this products. In Late Miocene, blocks from the Topuzdağ lavas and other lava flows from the region were transported to the lake floor by various processes. In Pliocene, the magma that went through fault systems interacted with the lake water and formed hyaloclastites at Eğrem Tepe. At the same period, Karain volcaniclastics are deposited.