|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Nitrogen isotopes in intra-crystal coralline aragonites
| Title: | Nitrogen isotopes in intra-crystal coralline aragonites |
| Authors: | Yamazaki, Atsuko Browse this author | | Watanabe, Tsuyoshi Browse this author →KAKEN DB | | Takahata, Naoto Browse this author | | Sano, Yuji Browse this author | | Tsunogai, Urumu Browse this author |
| Keywords: | Coral skeletons | | Nitrogen isotopes | | Pliocene | | Stepwise heating methods |
| Issue Date: | 2-Aug-2013 |
| Publisher: | Elsevier |
| Journal Title: | Chemical Geology |
| Volume: | 351 |
| Start Page: | 276 |
| End Page: | 280 |
| Publisher DOI: | 10.1016/j.chemgeo.2013.05.024 |
| Abstract: | To assess the preservation of the nitrogen isotope composition in reef corals, nitrogen isotopes in a well-preserved Pliocene fossil coral (located in the Tartaro formation on Luzon Island, Philippines (14°N, 121°E)) and in a modern coral (Kochi, Japan (32°N, 132°E)) were analysed using stepwise heating methods. The thermal decomposition of aragonite triggered the largest release of nitrogen at 700 °C for the modern coral and 550 °C for the Pliocene coral. The highest rate of nitrogen gas emission occurred at the aragonite collapse temperature, indicating that organic nitrogen was bound within the intra-crystals of coralline aragonites in both corals. After the aragonite collapsed in both corals, the nitrogen isotope ratios increased due to fractionation and then decreased to values similar to those observed in bulk samples of the modern (+ 10.1%) and Pliocene (+ 4.4%) corals. These results suggested that fresh organic nitrogen was released due to the decomposition of the internal skeletal structure at higher temperatures (900–1000 °C). Nitrogen isotopes in coral skeletons were preserved in intra-crystal aragonite, even in a Pliocene fossil, and stepwise heating methods were shown to be useful for determining the preservation of coralline nitrogen isotopes. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/56435 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 渡邊 剛
|
