嘎顺淖尔盆地新近纪以来孢粉组合与古环境特征

Spore-pollen assemblage and tentative palaeoenvironment feature in Gaxun Nur of Inner Mongolia since Late Tertiary

通过对内蒙古额济纳旗嘎顺淖尔湖深42.5m钻孔岩心沉积物的孢粉分析,探讨中更世以来湖盆周边的古植被变化特征.结果表明,该时期以温湿的森林植被为主导,可分为7个孢粉带.中更新世早中期,沉积物以洪积物为主,夹多层湖相层;中更新世晚期至晚更新世早期,沉积环境以湖滨相为主;晚更新世中期,沉积环境以浅湖相为主,夹湖滨相;晚更新世晚期,沉积相以湖滨相为主;晚更新世末期至全新世以浅湖相为主.从沉积特点看,嘎顺淖尔湖形成较晚.

The XK1 borehole of 42.5 m long obtained from Gaxun Nur,Ejina Qi of Inner Mongolia had provided us sediment since Late Tertiary. The spore pollen r ecords revealed the feature of vegetation during this period. The sporopollen an alysis suggested that conifer forest had dominated vegetation cover in the area. The vegetation had gone through seven stages corresponding to the change of pal aeoclimate. According to sediment feature,the sediment phase had undergone Pluv ial phase alternate with lacustrine facies from early to middle stage of Middle Pleistonce,shore deposit from late stage of Middle Pleistonce to early stage of Late Pleistonce,shallow lake alternate with shore deposit in middle stage of L ate Pleistonce,shore deposit in late stage of Late Pleistonce,and shallow phas e in Holocene. The Gaxun Nur forms in a relatively late period according to the feature of sediment.