滇东北拱王山地区全新世以来的气候环境变化

CLIMATIC ENVIRONMENTAL CHANGE DURING HOLOCENE IN GONGWANGSHAN, NORTHEAST OF YUNNAN PROVINCE

对滇北拱王山狐狸房峰南侧老碳房村附近冰蚀湖相沉积剖面进行粒度、磁化率分析,结合14C年代,建立了8.4ka至今的古气候环境变化序列。全新世早期以来经历5次较明显的气候波动:8.4～7.7ka,磁化率(xlf)变化在1.62～3.88μm3kg-1,粒度平均值为5.46φ,气候凉湿;7.7～6.5ka,粒度均值为5.83φ,磁化率降低,变化在1.44～2.28μm3kg-1之间,气候冷湿;6.5～4.7ka,粒度均值为5.95φ,磁化率值变化在1.53～3.65μm3kg-1之间,气候冷干;4.7～2.1ka,粒度均值为5.91φ,磁化率增加,变化在2.0～5.2μm3kg-1之间,气候凉湿;2.1ka以来,粒径平均值为5.63φ,磁化率值显著增加,介于3.44～6.33μm3kg-1之间,平均值为4.80μm3kg-1,气候以暖湿为主。

One continuous glacio-lacustrine sedimentary deposits, Laotanfang located on the southern side of Hulifang peak of Xiaojiang river, Yunan province were studied here in. Using grain size, environmental magnetic susceptibility and pollen analysis, together with the 14^C dating methods, the climatic environmental change since the Holocene epoch was discussed. The results reflected that the climate fluctuated in different stages during the Holocene, that is, the climate was cool and wet during 8.4-7.7ka with average grain size of 5.46φ and low frequency magnetic susceptibility （Xlf） 1.62-3.88μm^3kg^-1; Cold and wet during 7.7-6.5ka with average grain size of 5.95φand Xlf of 1.44-2.28μm^3kg^-1; Cold and dry during 6.5 -4.7ka with average grain size of 5.83φand Xlf of 1.53-3.65μm^3kg^-1; Cool and wet during 4.7-2.1 ka with average grain size of 5.91φand Xlf of 2.0-5.2μm^3kg^-1; Warmer and wet since the 2.1 ka with average grain size of 5.63φand Xlf of 5.63φ; Results reflect that the study area was influenced by both the southwest and southeast monsoons of different stages during Holocene.