[A-CC26] Ice cores and paleoenvironmental modeling

[ACC26-P09] Analyses of pollen grains and insoluble particles in an ice core drilled in the Pamir-Arai Mountains in central Asia

*Nozomu Takeuchi¹, Haruka Ogaya¹, Koji Fujita², Kenji Kawamura³, Akane Tsushima¹, Vladimir Aizen⁴ (1.Chiba University, 2.Nagoya University, 3.National Institute of Polar Research, 4.University of Idaho)

Keywords:ice core, pollen, central asia

We analyzed pollen grains and insoluble particles in an ice core drilled in the Pamir-Arai Mountains in central Asia. The ice core was drilled in August of 2016 on an ice cap of elevation 5300 m a.s.l. The length of the ice core was 36 m from the surface to the bedrock. Microscopy revealed that the ice core contained mainly three morphological types of pollen grains, which are likely to correspond the genus of Juniperus, Artemisia, and Ephedra. Using the variations in these pollen concentrations in the ice core, annual layers were determined from the surface to the depth of 15 m for 21 years. In the section between the depths of 15 m and 26 m, little pollen grains were found in the ice core. The lack of pollen grains in the section is probably due to refrozen ice originated from water filled in a crevasse. Below the depth of 26 m, the pollen grains appeared again down to the bottom of the ice core. We found the charcoal particles in several layers in the deeper part of the core, suggesting that forest fires occurred in the past in this region. We also found pure calcite particles in some layers, which appeared not to be derived from terrestrial surface, but from a geyser because silicate mineral particles were not contained in the layers. Although this ice core did not appear to preserve a continuous past climate information, particle analyses could reveal unique environment events in this region of central Asia.