DATE2019-01-08 12:44:22
AUTHORSKürsad Kadir Eris (1)|Namik Çagatay (2)|Tugçe Nagihan Arslan (3)|Sena Akçer Ön (4)|Demet Biltekin (5)|Dursun Acar (6)|Zülfü Gürocak (7)|Özlem Öztekin Okan (8)
  1. Firat University, Elazig, Turkey
  2. Istanbul Technical University, Istanbul, Turkey
  3. Firat University, Elazig, Turkey
  4. Mugla Sitki Koçman University, Mugla, Turkey
  5. Firat University, Elazig, Turkey
  6. Firat University, Elazig, Turkey
  7. Firat University, Elazig, Turkey
  8. Firat University, Elazig, Turkey
ABSTRACTThe Lake Hazar is located on the left-lateral East Anatolian Fault Zone (EAFZ) at ~1100 m elevation on the East Anatolian Plateau. Precise correlation of high-resolution seismic and core stratigrafies in this study provided an accurate chronology for lake level changes and multi-proxy core data for climate during the last 30 ka BP. Subdivision of the lake infill into different facies in the seismics and cores reveals different subenvironments, each subject to a distinctive hydrological and sedimentological processes controlled by the climatic changes. An abrupt climatic shift at the transition from MIS-3 to MIS-2 is recorded in seismic profiles by formation of progradational unit below -80 meter below present lake level (mbpll) on the shelves of the lake. The continued lake level drop was modulated by formation of -93 mbpll paleo-terrace, and then attined its maximum lowstand at -105 mbpll due to cold and dry climate at the onset of Last Glacial Maximum (LGM). The initiation of the Bølling/Allerød interstadial is documented by multi-proxy analyses of the cores displaying increased physical weathering and erosion in the catchment, thus resulting in high clastic sediment supply due to warm and wet climate during this period. The last climatic drought prior to the Holocene is recorded in the cores during the Younger Dryas (YD) that is marked by a major unconformity surface in the seismic profiles. This major shelf-crossing unconformity surface truncates older sedimentary units below, implying a lowstand water level of the lake at -73 mbpll. According to pollen record, the beginning of Holocene was associated by an expansion of vegetation due to increased warming and humidity after the YD, which was associated with a sudden lake level rise recorded by subaqueous paleo-terraces at -63 mbpll and -56 mbpll in the seismic profiles. At the beginnig of mid-Holocene, the higher humidity in Eruope and eastern Mediterranean allowed wide-spread delta depositions. Increasing moisture and consequently high river runoff prevailed in Lake Hazar, with the major Kürkçayi River building an extensive delta over the western shelf of the lake. The onset of the late Holocene is associated with rising lake level above -38 mbpll, followed by a remarkable climatic shift to the major drought period during the late Holocene is only recorded at 2.7 ka BP when the lake level decreased about by ~ 15 to ~-43 mbpll.