8.4ka以来纳木错湖芯介形类组合的环境变化意义(英文)

编号 zgly0001586027

文献类型 期刊论文

文献题名 8.4ka以来纳木错湖芯介形类组合的环境变化意义(英文)

作者 谢曼平  朱立平  彭萍  王君波  汪勇  SCHWALBAntje 

作者单位 InstituteofTibetanPlateauResearch  CAS  GraduateUniversityofChineseAcademyofSciences  InstitutfürUmweltgeologic  TechnischeUniversitt 

母体文献 Journal of Geographical Sciences 

年卷期 2009年04期

年份 2009 

分类号 P532 

关键词 ostracods  environmentalchange  lacustrinecore  NamCo  TibetanPlateau 

文摘内容 A 332-cm long lacustrine core was drilled in the Nam Co in the central-southern part of the Tibetan Plateau. From the core, 15 species of ostracods (Crustacea: Ostracoda), which belong to 6 genera have been identified. According to the variations of the ostracod assemblages and the ostracods ecological features, which are sensitive to the changing environment, three main stages can be distinguished as follows: Stage I was from 8400 to 6800 a BP, during which the climate was cold-humid, and the lake depth changed from shallow to deep. Stage II was from 6400 to 2500 a BP, during which the climate changed from warm-humid to cold-humid, and then to cold-dry. The lake depth gradually became deep. The shifting of climate, from wet-cold to dry-cold during this period, had constructed the basis of present environment in the Nam Co. Stage III was from 2500 a BP to the present, which showed a trait of lake depth increasing. At the earlier period of this stage, the climate kept as cold-dry as that in the former stage, but the salinity of the lake increased. At the later period of this stage, the degree of cold-dry was enhanced, and the activities of land surface runoff tended to be weakened. Our research also found that the peak values of ostracods with black shell was coherent with the maximum production of the ostracods, and agreed with the increasing sedimentary water dynamics. This indicated that the ostracods with black shell was simultaneous with the high prolificacy of ostracod, and transported from other places. The abundance of Candona juvenile shells reflected the high mortality of that kind of ostracods under an unfavorable condition. This was probably a result of the rapid change of water dynamics of sedimentary environment.