2004 Fiscal Year Final Research Report Summary
The Reconstruction of the Paleoenvironments in the Western Desert China by using of the Alkenone proxy
| Project/Area Number |
14209012
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
広領域
|
|---|
| Research Institution | Nagoya University (2004)
Aichi Prefectural University (2002-2003) |
|---|
Principal Investigator |
NISHIDA Tamihito Nagoya University, Graduate School of Environmental Studies, Research Associate, 環境学研究科, 助手 (60313988)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TANOUE Eiichiro Nagoya University, Graduate School of Environmental Studies, Professor, 環境学研究科, 教授 (50133129)
HARADA Naomi Japan Agency for Marine-Earth Science and Technology, Researcher, 研究員 (70344281)
UCHIDA Masao Japan Agency for Marine-Earth Science and Technology, Researcher, 研究員 (50344289)
SHIRAIWA Yoshihiro University of Tsukuba, Institute of Biological Science, Professor, 生物科学系, 教授 (40126420)
HARA Seiko Mryazaki International College, Faculty of Comparative Culture, Professor, 比較文化学部, 助教授 (50261243)
|
|---|
| Project Period (FY) |
2002 – 2004
|
| Keywords | Saline lake / Desert Area in China / Reconstruction of Paleoenvironment / Alkenone temperature / Climate Change / Lignin-Phenol / Holocene / Nitrogen isotope ratio |
|---|
| Research Abstract |
An aim of this work is to reconstruct the paleoenvironmental change of the present to the middle Holocene surrounding the saline lakes in the western to northeastern desert China. To achieve this aim, several proxies such as C/N ratio of sediment organic matter, long chain alkenones ratio, carbon and nitrogen stable isotope ratios and lignin-phenols were applied to the sediment samples collected from the Bosten Lake in the Xinjiang Uygrur Zizhiqu ( 41° 56.176 'N,86° 48.055 'E, Altitude 1.030 m ) and the DaBuSu Lake in Jilin (44° 45.20 'N,123° 34.30 'E, Altitude 450 m) and following results were obtained.
1)The reconstruction of the paleoenvironmental change in the Bosten Lake
(1)Alkenone temperatures ranging from 0.5 to 10.1℃ were found for the surface water of this lake after 3.5 kyrBP to the present. The temperature change was further divided to the three stages of (a)the cold climate before 3.5 kyrBP, (b)the warm climate between 2.7-1.5 kyrBP and (c)relatively cold climate after 1.5 kyrBP to the present.
(2)Carbon and nitrogen stable isotope ratios suggested that material cycles of this lake were changed to a great extent due the nitrogen fixation process and vegetation change surrounding the lake.
2)The reconstruction of the paleoenvironmental change in the DaBuSu Lake
(1)Analytical data of the lignin phenols of the sediment samples indicated that the marked change of vegetation surrounding this lake is distinctive from the Gymnosperm (present to 3 kyrBP) to the Angiosperm (3-5 kyBP). This suggests that this area has a warm climate in the middle of the Holocene.
(2)Relatively high values of the Alkenone temperature ware obtained in the sediment samples from 3-5 kyrBP. The results were basically agreed to the vegetation change of this lake area.
|
