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

半球气候变化和大型构造湖古环境变迁的基础研究。

基本信息

批准号：
03044165
负责人：
TOYODA Kazuhiro
金额：
--
依托单位：
Mineralogical Institute, University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Overseas Scientific Survey.
财政年份：
1991
资助国家：
日本
起止时间：
1991 至无数据
项目状态：
已结题

项目摘要

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

1。计划在当前主题上进行联合工作，我们将研究集中在南非和贝加尔湖上；在典型的构造湖泊（如Tanganyika和Baikal）中都观察到了最杰出的特征作为构造湖泊。作为研究Tanganyika湖的第一步，我们开始了对Verloren Vlei获得的核心样本的地层研究，因为坦基尼卡湖和Malauii被认为是延伸到南部海岸的非洲构造主义的一个单位。另一方面，俄罗斯和美国的联合工作在Paikal湖也由日本和Netherlanderss支持了Paeikal湖。我们获得了4.61m长的核心的暂定示例，以比较Biwa和Baikal之间的湖泊类型。我们已经获得了非常有价值的数据。这些学术数据在IPPCCE新闻信中印刷。由于这两个古老的湖泊沉积物的结果，我们可以获得研究世界上两种杰出的构造主义的线索。2。结果，南非的结果……更多的是，我们获得了50m长的核心和花粉分析工作，由Meadow博士完成，而Granurmemportric工作是由开普敦大学Parking Tarkton教授的主持下进行的。另一方面，我们在盐湖湖上获得了300，000年历史的核心样本，在该湖中，在教授的指导下，Sara Kerr博士进行了花粉分析工作。斯科特和帕特里奇。 Althuth仍然很难澄清整个气候成功，很明显，在与更新世的北半球相关的年龄，南非遭受了寒冷的攀登。为了获得地磁特征，不幸的是，由于存在许多非磁性矿物质的原因（低于3 x 10^<-7> emu/cm^3）。在Baikal的情况下，4.61m核心证实了存在两个环境单位。在这方面，更新世 - 西陆边界似乎是1.5米的深度。在北部盆地的700m深地点，沉积率可能为0.01mm。在150万个水平上，发现大量的浮游硅化石化石与低于该水平的硅藻化石数量相反。高于该150万人被认为是全新世温暖的气候沉积。那个年龄可能会引起高生产率。它与Biwa湖沉积物的情况相似。关于花粉颗粒，我们可以发现低于150万级的气候繁殖，表示WURM气候波动。从有机化学的角度来看，作为森林的陆地生产与湖泊有机体的自动变化相吻合，例如浮游硅藻和浮游动物的组成。它也与BIWA湖历史相媲美，该历史支持湖泊Biwa和Baikal在北半球建立年表的可能性。较少的