Experimental study on fossilization and nodule formation

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21898
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: Kanazawa University
• Principal Investigator: Jenkins Robert 金沢大学, 地球社会基盤学系, 准教授 (10451824)
• Co-Investigator(Kenkyū-buntansha): 長谷川 卓 金沢大学, 地球社会基盤学系, 教授 (50272943)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 化石化過程 / 化石成因論 / 鯨骨群集 / 物質循環 / 炭素循環

Outline of Final Research Achievements

In this study, we measured dissolved oxygen concentration of seawater in/around deployed whale carcass during its decay. Oxygen concentration was measured. As results of measurements, decomposition of whale bones with soft tissue forms less than 1 cm thick dysoxic environment on the bone surface. After removal of the soft tissue around the bones, the dysoxic environment area shrinks to 2 mm thick on the bone surface and the inside of the bone was anoxic. To understand mineralization of bones and precipitation of authigenic minerals on/within bones, it needs to reveal chemical condition within the bones. After we tried and investigated several methods, it has been revealed that using 2D O2-Sensor film on a sectioned bone is useful.

Free Research Field

古生物学

Academic Significance and Societal Importance of the Research Achievements

生物遺骸の分解は生態系の物質循環において欠かせないプロセスであるが，人類はその実態の一端しか理解できていないのが現状である．本研究では，地球上最大の有機物塊である鯨類遺骸を題材に，遺骸分解プロセスの解明に挑んだ．その結果，骨の内外で有機物の分解速度がまったく異なり，また，骨表面を境とした急激な化学勾配があることを明らかにした．また，新規手法開発によって硬組織(骨)内部の化学環境モニタリングの実現可能性に具体的に迫ることができた．これは，生態系における物質循環（炭素循環）の実態解明や生体硬組織（もしくはその疑似人工物）を利用した炭素固定法などへの応用にもつながることが期待される．