Characteristics and development of soft-sediment deformation structures observed kirkgeçit formation (Western Elazig)

The Elazig basin is one of the developed basins during the closure of the southern branch of Neotethys in Tertiary. The Elazığ basin extending in the NE-SW direction is located in the Eastern Taurus Mountains. The Palu county is bounded by the East, the Peri river and Keban Dam Lake to the north, the Euphrates to the west and southwest and the Karga Mountain and Mastar Mountain to the south and south-east. In and under this basin, metamorphic, magmatic and sedimentary rocks of varying age range from Permo Triassic to Plio-Quaternary. The units in the study area consist of Permo-Triassic Keban Metamorphites, Senonian Elazığ Magmatites, Maastrichtian Harami Formation, Early Paleocene Kuşçular Formation, Late Paleocene-Early Eocene Seske Formation, Middle Eocene-Oligocene Kırkgeçit Formation, Early Miocene Alibonca Formation, Plio-Quaternary Palu Formation and present alluvium Soft sediment deformation structures forming the subject of this work were observed in two regions within the Kırkgeçit Formation in the est of Baskil (Elazığ) . These; 1.Around Hacıtemur village, 2. Around Saluşağı village, Kırkgeçit Formation consists of low inclined slope and reef sediments formed by calcarenite-carbonate mudstone (marl) alternation around Hacıtemur village. The commonly observed slump features in the study area are described in low slope slope deposits consisting of calcarenite-carbonate mudstone facies. The direction of movement of slump structures continuing up to 5 km was determined as south-southeast. Kırkgeçit Formation consists of conglomerate, sandstone and marl facies slope deposits consisting of dense channel deposits south of the study area (around Salusagi village). This region has been deposited in a deeper area than the north facies. Various soft sedimentary deformations were observed in the facies. These are slump features, chaotic deposits, load casts, flame structures, water escape structures (water-flow structures between layers), convolute lamination, clastic dykes and syn-sedimentary faults. The deformation mechanism of the described soft sedimentary deformation structures is related to liquefaction, fluidization, brittle behavior and density difference. The mechanism that initiates deformation is related to rapid sedimentation, slope inclination, and tectonic and seismic activity in the region.