| Project/Area Number |
15K17781
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Stratigraphy/Paleontology
|
|---|
| Research Institution | Osaka City University (2017-2018)
Naruto University of Education (2015-2016) |
|---|
Principal Investigator |
ADACHI NATSUKO 大阪市立大学, 大学院理学研究科, 准教授 (40608759)
|
|---|
| Research Collaborator |
Liu Jianbo
Yan Zhen
DORJNAMJAA Dorj
ALTANSHAGAI Gundsambuu
ENKHBAATAR Batkhuyag
WATABE Mahito
EZAKI Yoichi
|
|---|
| Project Period (FY) |
2015-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2015: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
|---|
| Keywords | カンブリア紀 / 絶滅事変 / 微生物類礁 / 古杯類 / 中国 / モンゴル / 地球表層環境 / 生物礁 / 微生物岩 |
|---|
| Outline of Final Research Achievements |
This study examined changes in the compositions of reef-building organisms and the mode of reef construction before and after the extinction event at the end of the Cambrian Epoch 2, focussing on Gobi-Altai Province in western Mongolia and Shandong Province in North China. The appearance of calcimicrobes (e.g., Epiphyton), which were the main reef-builders throughout the Cambrian, was largely coincident with the appearance of small shelly fossils and the diversification of trace fossils. During the interval in which archaeocyaths flourished (Epoch 2), the archaeocyaths and calcimicrobes show a high degree of diversity and botryoidal cement was produced in reefs. In contrast, after the demise of archaeocyaths (Miaolingian), calcimicrobes show a loss of diversity and botryoidal cement was not produced in reefs. The types and diversity of reef-building organisms and marine environments (e.g., the Mg/Ca ratio in seawater) are inferred to have changed across the extinction event.
|
| Academic Significance and Societal Importance of the Research Achievements |
モンゴルゴビ・アルタイ地域と北中国山東省に分布するカンブリア紀第二世末に生じた絶滅事変前後の礁を対象として研究をおこない，カンブリア紀に大繁栄した石灰質微生物類礁の確立時期と造礁生物古杯類や石灰質微生物類の多様性の変化，古杯類礁の構築における石灰質微生物類とセメント (アラゴナイト起源のセメント等) の役割を明らかにした．これら成果は，絶滅事変前後での礁生態系と海洋古環境の変化を明らかにするだけでなく，後生動物の爆発的多様化と大規模絶滅事変の両方が生じたカンブリア紀の地球生物環境の実態を解き明かすことに繋がる．
|
