Basic Study on Hemispheric Climatic Changes and on Transition of Paleoenvironments in Huge Tectonic Lakes.

1.在我们关于本专题的联合工作中，我们集中研究了南非和贝加尔湖;在坦噶尼喀和贝加尔湖等两个典型的构造湖中观察到了构造湖最显著的特征。作为坦噶尼喀湖研究的第一步，我们首先对在Verloren Vlei获得的岩心样品进行了地层学研究，因为坦噶尼喀湖和Malauii湖被认为是向南部海岸延伸的非洲构造活动的一个单元。另一方面，在日本和荷兰的支持下，俄罗斯和美国联合开展了Paikal湖的古湖泊学研究。为了比较琵琶湖与贝加尔湖的湖型划分，我们获得了4.61m长的岩心试例。我们已经获得了非常有价值的数据。这些学术资料刊登在IPPCCE新闻通讯中，通过这两个古湖泊沉积的研究，我们可以获得研究世界上两个不同构造运动的线索.在南非， ...更多信息 我们获得了50米长的岩芯，Meadow博士完成了花粉分析工作，开普敦大学Parkington教授的指导下的人完成了粒度测定工作。另一方面，我们在盐田湖获得了30万年前的岩芯样品，其中花粉分析工作由Sara Kerr博士在教授的指导下进行。斯科特和帕拉迪纳尽管整个气候演替过程至今仍难以明确，但在更新世与北方半球对应的时期内，南非曾遭受过寒冷气候的影响。对于地磁特征的结果，由于存在大量的非磁性矿物（低于3 × 10^<-7>emu/cm ^3），不幸的是并不成功。在贝加尔湖的情况下，4.61米的岩芯证实了两个环境单元的存在。在这方面，更新世-全新世界线似乎是1.5米深的水平。在北方盆地700 m处，沉积速率可能为0.01 mm。在1.5m以上发现了大量的硅藻化石，而在1.5m以下则发现了少量的硅藻化石。以上1.5m为全新世温暖气候存款。这个年龄可能会导致高生产力。这与琵琶湖沉积物的情况类似。在花粉粒方面，1.5m以下存在较冷的气候亚阶段，反映了乌尔姆气候的波动。从有机化学的观点来看，森林等陆地生产与湖泊生物如浮游硅藻和浮游动物组成的原地变化相一致。它也与琵琶湖的历史相比较，支持通过琵琶湖和贝加尔湖在北方半球建立年表的可能性。少

1. PROGRAM CARRIED OUTIn our joint work on the present theme, we had concentrated our study to South Africa and lake Baikal ; the most distinguished features as tectonic lake are observed in both typical tectonic lakes such as Tanganyika and Baikal. As the first step to study Lake Tanganyika, we started stratigraphic study on the core sample obtained in Verloren Vlei because Lakes Tanganyika and Malauii is regarded as one unit of African tectonism extending to southern coast.On the other hand, paleolimnological study is carried out in Lake Paikal by Russian and American joint work supported also by Japanese and Netherlanders. And we obtained tentative example of 4.61m long core in order to compare the succesion of lake type between Biwa and Baikal. We already obtained very valuable data. These academic data are printed in IPPCCE News Letter.As the result of these two ancient lake sediments, we could obtain clue to study two distinguished tectonism in the world.2. RESULTIn South Africa, … More we obtained 50m long core and pollen analytical work was done by Dr. Meadow and granurometric work was carried out by people under auspice of Prof. Parkington, University of Cape Town. On the other hand, we obtained core sample of 300, 000 years old at Lake Saltpan in which pollen analytical work was carried out by Dr. Sara Kerr under the guidance of Profs. Scott and Partridge. Althouth it is still difficult to clarify the whole climatic succession, it is clear that South Africa had been suffered by cold climate during the correlating age with the Northern Hemisphere in the Pleistocene. For result on geomagnetic feature, it is unfortunately not successful for the reason of lot of non-magnetic minerals existence (below 3 x 10^<-7> emu/cm^3).In the case of Baikal, 4.61m core had verified the existence of two units of environments. In this regard, Pleistocene-Holocene boundary seems to be 1.5 meters deep level. Probably the sedimentation rate might have been 0.01mm at the 700m deep spot in the northern basin. Above that 1.5m level, plenty of planktonic diatom fossils were found on the contrast to poor amount of diatom fossils below that level. Above that 1.5m is regarded as Holocene warm climate deposit. That age might cause high productivity. It is similar with the case of Lake Biwa sediments. Regarding pollen grains, we can find out colder climate substage below 1.5m level denoting Wurm climate fluctuation. From the view-point of organic chemistry, terrestrial production as forest coincides with the autochthonous variation of lake organism such as planktonic diatom and also zooplankton composition. It is also comparable with Lake Biwa history supporting the possibility of establishing chronology in the Northern Hemisphere by both Lakes biwa and Baikal. Less