Holocene Environment Changes Inferred From The GDGTs From The Peatlands In Altai Mountains, Xinjiang

The analysis of GDGTs under the high-confident chronological framework of the core ATM10-C4at the Altay Mountains, Xinjiang has been conducted. By modeling the climatic and environmental history in this area over the Holocene with several GDGTs proxies, the adaptability of different GDGTs proxies under the sedimentary environment of peatland is also evaluated. Based on previous age model and the result of loss on ignition, we compare it with the analysis of plant residue of this core, thus providing invaluable information for exploring the application of peatland GDGTs in climate change.The variation of pH which reacted by branched GDGT with high reliability reaction Combined with the LOI and plant macrofossil analysis, the reconstruction of paleoclimate and paleoenvironment shows that in the early Holecene (11.1-9.Oka), the surface of peatland was quite wet and the water level was rather high, growing eutrophic low-moor peat with Cyperaceous plants. In the mid-Holecene (9.0-4.4ka)-the Holocene Optimum, the surface of peatland was the humidest in this period, when Cyperaceous plants flourished. In the late Holecene, the water level decreased and oligotrophic high-moor peatland began to develop, while Cyperaceous plants reduced and sphagnum which adapted aridity increased,indicating that the climate was the driest. After1.2ka, moisture on peatland surface added and the water level rose, with Cyperaceous plants multiplying, which inferred that the climate was ameliorated.