Tortum Gölü (Erzurum) kuzeyinin stratigrafik ve sedimentalojik özellikleri

Abstract

SUMMARY Sedimentological and stratigraphical properties of northestern of Tortum Lake (Erzurum) This study aims at investigating the stratigraphical and sedimentological properties of northern Tortum Lake (Erzurum). The basement of the study area is made up of by the Hamurkesen Formation consisting of volcanic-, volcani-clastic-, and sedimentary facies rocks. The lithological and sedimentological features of this formation indicate that it precipitated in terrestrial to shallow marine environments. This formation is conformably overlain by the Malm- Lower Cretaceous aged and transitional Posburun Tepe Formation and Kayadibi Formation. While Posburun Tepe Formation consist of pelagic limestones, Kayadibi Formation contains neritic limestones. Posburun Tepe Formation is unconformably overlain by the Çağlayan Formation containing four turbidity sequences with upward coarsening grain size. Examined sandstone samples which are from Çağlayan Formation are mineralogically and texturally immature and plot in the fields of feldspathic lithic- and lithic arenite. The source area studies show that their components are derived from magmatic arc rocks. Contour diagrams indicate that the study area was subjected to two different pressures along NW-SE and NE-SW directions respectively. Total organic carbon values of the investigated shales which could be considered as a possible source rock, vary from 0. 1 to 0.5% and imply that they cannot form a source rock. Key words: Tortum Lake (Erzurum), strtaigraphy, sedimentology, origin, source rock, sandstone.

SUMMARY This study aims at investigating the stratigraphical and sedimentological properties of northern Tortum Lake (Erzurum). The basement of the study area is made up of by the Hamurkesen Formation consisting of volcanic-, volcani-clastic-, and sedimentary facies rocks. The lithological and sedimentological features of this formation indicate that it precipitated in terrestrial to shallow marine environments. This formation is conformably overlain by the Malm- Lower Cretaceous aged and transitional Posburun Tepe Formation and Kayadibi Formation. While Posburun Tepe Formation consist of pelagic limestones, Kayadibi Formation contains neritic limestones. Posburun Tepe Formation is unconformably overlain by the Çağlayan Formation containing four turbidity sequences with upward coarsening grain size. Examined sandstone samples which are from Çağlayan Formation are mineralogically and texturally immature and plot in the fields of feldspathic lithic- and lithic arenite. The source area studies show that their components are derived from magmatic arc rocks. Contour diagrams indicate that the study area was subjected to two different pressures along NW-SE and NE-SW directions respectively. Total organic carbon values of the investigated shales which could be considered as a possible source rock, vary from 0. 1 to 0.5% and imply that they cannot form a source rock. Key words: Tortum Lake (Erzurum), strtaigraphy, sedimentology, origin, source rock, sandstone.