摘要
本文取材于1987年6月中美双方对云南中部石灰岩分布区5个高原湖泊用美方Minnesota方管活塞式取样设备采集的湖底表层沉积物样品。5个湖泊是:通海杞麓湖,宜良草甸海,路南长湖及月湖,寻甸清水海。(图1)各自具有不尽相同的微体生物化石群。虽然由于取样的数量、深度及位置所限,本文很可能未能完全反映这些湖泊中的全新世生物群,但总的面貌已能代表。涉及到的门类有:节肢动物门甲壳纲介形类亚纲、鳃足亚纲贫鳃足部枝角目,腹足动物及其口盖,脊椎动物鱼类器官,轮藻等。这些生物群均已石化,保存精良,
This paper is one of the research results cooperatively completed by Sino-American scientists. The assemblages, zonings, surface ornaments, shell components and microelements in microfossils which were collected from the surface layer sediments of 5 plateau lakes in central Yunnan are depicted and determined; on this basis, the authors discussed the feature of environment where the microfaunas lived in and demonstrated the ecologic environment at that time. The fossil Daphnid Ceriodaphnia yunnensis(sp. nov.)of lake bottom sediments on the plateau is firstly reported; the new genera of Metacandona and Paracyclocypris in Ostracoda, 8 new species and a new form of operculum in Gastropoda are described in this paper. The assemblage zones are now divided into the Metacandona zone(0.02—2.58m), Condona zone(3.01—5.63m)in the Qilu lake of Tonghai and the Paracyclocypris—Metacypris zone in the Chang lake of Lunan. The paleoenvironment reflected by the biologic group has been discussed. The author considers that the boundary between the Holocene and Pleistocene should be placed at the 6 m of vertical depths in sediments showing a extreme cold event in climate of the Qilu lake, which can represent a turning point for the plateau lakes in central Yunnan.
出处
《云南地质》
1990年第2期117-133,共17页
Yunnan Geology
