台灣南灣地區微孔珊瑚微構造之應用

Application of micro-structure on a Porites coral from Nanwan Bay, southern Taiwan

劉峻鳴(Chun-Ming Liu)

指導教授 ： 宋聖榮

國立臺灣大學/理學院/地質科學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.03119

摘要

無資料

關鍵字

微孔珊瑚 ； 微構造 ； 台灣 ； 珊瑚大產卵 ； 環境變遷

並列摘要

Coral has been one of the best materials to study climate change. Researchers use the variations of trace elements and stable isotopes in coral skeletons to reconstruct environment at the time of its deposition. However, the coral growth is not always in the same direction due to environmental changes or unknown reasons. It, thus, has problem for climatic changes by slicing coral samples along the major axis of growth. That is why we need to check the micro-structure of coral skeletons for further study.
In this study, we collected Porites sp. coral which has completed slicing subsamples along the major axis of growth from the Nanwan bay, Taiwan. Then, we use the scanning electron microscope (SEM) to get secondary electron (SE) and backscattered electron (BSE) images. Comparing the images of X-ray, SE and BSE, we found that the growth direction of coral is quite different to the major axis of growth. It means that there were some problems in the samples sliced along the major axis of growth currently. On the other hand, we found low density bands in the X-ray and BSE images, and it is well correlated to anomalous Ba/Ca ratios. Accordingly, low density bands in Porites sp. coral from the Nanwan bay seems to be likely originated by coral mass spawning. Therefore, we use those low density bands to construct age model in advance. Further, we use dissepiments which are the skeletal structure in coral to push time resolution scale to monthly.
Therefore, using the micro-structures of coral can avoid the problem which growth direction of coral change, and can construct age model more accurately.

並列關鍵字

Porites coral ； micro-structure ； Taiwan ； coral mass spawning ； environmental changes

參考文獻

姜宏偉 (2011) 臺灣南部珊瑚骨骼中之氧同位素和鋇鈣比紀錄及其環境解釋. 博士論文, 國立臺灣大學.

Alibert, C., Kinsley, L., Fallon, S. J., McCulloch, M. T., Berkelmans, R. and McAllister, F. (2003) Source of trace element variability in Great Barrier Reef corals affected by the Burdekin flood plumes. Geochimica et Cosmochimica Acta 67(2): 231-246.

Allison, N. and Finch, A. A. (2007) High temporal resolution Mg/Ca and Ba/Ca records in modern Porites lobata corals. Geochemistry Geophysics Geosystems 8: 1-11.

Allison, N., Finch, A. A., Newville, M. and Sutton, S. R. (2005) Strontium in coral aragonite: 3. Sr coordination and geochemistry in relation to skeletal architecture. Geochimica et Cosmochimica Acta 69(15): 3801-3811.

Barnes, D. J. and Lough, J. M. (1993) On the nature and causes of density banding in massive coral skeletons. Journal of Experimental Marine Biology and Ecology 167(1): 91-108.