Akademik Veri Yönetim Sistemi
Journal of African Earth Sciences, cilt.235, 2026 (SCI-Expanded, Scopus)
Stratigraphic and structural features of the Aşkale-Pasinler-Horasan basins located within the borders of Erzurum Province in the Eastern Anatolia Region were investigated to depths of approximately 3–4 km by evaluating 1300 km of multichannel 2D seismic reflection data and three boreholes collected in the region between 1977 and 2001. A total of eight seismic units ranging from Mesozoic to Plio-Quaternary were interpreted within the basins. Seismic stratigraphy and structural features show that Aşkale, Erzurum, Pasinler and Horasan basins were initiated and began to shape during the tectonic regime extending from the Mesozoic to the Late Miocene, with possible strong compression, rapid uplift and long-term erosion processes, respectively. Particularly, Mesozoic Ophiolites play an important role to form these basins and ridges geometry at present. Because both the ophiolites are widespread under the Neogene deposits of basins and the wells drilled in this region penetrate into the ophiolitic melange by cutting through the Neogene deposits. The Late Miocene erosional surface is overlain by very gently accumulated horizontal sediments deposited from the Upper Miocene to present within the basins (∼2.0 km thick). These interpretations on the seismic sections indicated that compressional tectonic regime has remarkably left the region after Late Miocene. However, within the Plio-Quaternary sediment strata, several active N-S to NE-SW oriented strike-slip faults with reverse components, WNW-ESE oriented strike-slip faults and ENE-WSW oriented positive flower structures were mapped. These faults are interpreted as Plio Quaternary in age, which are responsible for the recent deformation in the basins and their surrounding region. The major of them either overlap with the previously mapped active Aşkale, Erzurum and Pasinler fault zones in the region or form their continuations within the basin. These compressional strike-slip faults border the basins and elevate the ridges to the north and to the south. Thus, they form ramp basins structures in the Aşkale, Pasinler and Horasan. In addition, newly mapped strike-slip faults and positive flower structures squeeezed the basin deposits within the Aşkale, Erzurum and Horasan basins. It is seen that the basins and ridges have recently been under a compressional strike-slip tectonics. The quantitative analysis of earthquake focal mechanisms supports our fault orientation and character. It reveals an approximately NNE-SSW maximum horizontal stress (SHmax) orientation within these basins which is primarily controlled by the continental collision between the Arabian and Eurasian plates.