摘要
探讨了利用漫反射红外傅立叶变换光谱(DRIFTS)来快速定量测定深海沉积物中方解石含量。以北大西洋深海沉积物为例,对标样进行DRIFTS测量,选取碳酸钙713cm-1特征峰(方解石)与石英800cm-1特征峰面积比值作为回归参数,同时用气量法测试标样的方解石含量,然后分析DRIFTS特征峰强度与方解石含量的相关性,建立校准方程并检验。结果显示,DRIFTS方法对沉积物方解石含量测量准确,尤其对低方解石含量的样品比较敏感,具有较低的检出限和较高测量精度。应用该校准方程,对北大西洋综合大洋钻探计划(IODP)U1308站位近1Ma来沉积物进行测定。其方解石含量呈典型的大西洋型旋回,反映了中布容事件(MBE)以及中更新世革命(MPE)时期方解石含量变化较大;在响应全球气候变化趋势的同时,还体现了全球碳储库变化对于北半球冰盖增长的触动机制,大洋内部深水循环影响方解石的保存。
A rapid and simple method based on diffuse reflectance coupled with lnfrared Fourier Transform Spectroscopy （DRIFTS） was developed for the quantification of calcite content in deep sea sediments. Taking the drilling site U1308 from North Atlantic as an example, the standard sediment sample was put on DRIFTS detection and the area ratio of calcite peak 713 cm^-1 to quartz peak 800 cm^-1 was set as independent variable. The calcite content was obtained by Vacuum-Gasometric technique, and the correlation between DRIFTS area ratio and calcite content was analysed and a regression equation was validated. The results show that the DRIFTS method can clearly quantify the calcite in sediments, which is especially sensitive for the low calcite content with good mesure precision and detection limit. In this way, we determined the calcite content for drilling site U1308 sediments of recent nearly 1 Ma, which displays typical Atlantic carbonate cycle. It reflects intensified changes in calcite preservation during mid-Brunhes event （MBE） and mid-Pleistocene evolution （MPE）. In response to global climate change, it also reflects the driven force mechanism of global carbon reservoir changes in North hemisphere ice sheet expansion and influence of deep water circulation on calcium carbonate preservation.
出处
《高校地质学报》
CAS
CSCD
北大核心
2009年第2期184-191,共8页
Geological Journal of China Universities
基金
国家自然科学基金项目(40625012
40773056)资助
