ポスター発表
- 第2日 5月16日（火） P会場（ホワイエ，会議室1004-1007）
-
2P-38 PDF
ラマン質量分析装置を用いた炭酸塩鉱物の酸素同位体比の精度評価
The oxygen isotope ratio of calcium carbonate varies with temperature. The δ18O of carbonates is often used to infer past climatic and hydrologic variability from a wide variety of materials and environments, including cave deposits (speleothems), corals, carbonate shells from marine and freshwater organisms, and inorganic and organic carbonates deposited in lake sediments and soils. Therefore, attention was focused on micro-Raman spectroscopy, which can be analysed with a spatial resolution of 1 µm. The precision of isotope ratio analysis using Raman spectroscopy has rarely been discussed. McKay et al. (2012) measured Raman spectra of calcite, which determined an error of 210‰ from the intensity ratio of the Raman spectra of calcite. However, the existence range of the natural oxygen isotope ratio is 166‰, which makes its application to natural samples difficult.
We measured with higher resolution and sensitivity than in previous studies. As a result, we were able to determine the oxygen isotope ratio of calcium carbonate from the Raman spectra with a precision of up to 9.7‰. This precision is two orders of magnitude lower than in previous studies.