(Table 2) Weight percent organic carbon from ODP Site 138-847@en

As the length of marine cores increases and sampling intervals decrease, the need for rapid and inexpensive means of determining sediment composition has become apparent. In this study we examine one potentially useful technique for assessing compositional changes in marine cores, diffuse reflectance spectrophotometry. We examined near-ultraviolet, visible, and near-infrared reflectance spectra from five data sets. Each data set consists of calibration samples and test samples. The calibration samples' spectra were related to a sediment component using multiple linear regression. The resulting regression or calibration equations were then evaluated using the test samples. Calibration equations were written relating spectra to several sediment components incduding carbonate (Atlantic and east Pacific Rise ODP Site 847), organic carbon content (Atlantic and east Pacific Rise), and opal content (east Pacific Rise). The correlation coefficients for the regression equations ranged from a high of 0.99 for carbonate and opal at ODP Site 847 to a low of 0.97 for Atlantic carbonate indicating that spectral variations are highly correlated to sediment composition. All of the equations include a substantial number of variables from shorter visible and longer near ultraviolet wavelengths suggesting that these wavelengths are especially important for devices designed specifically to scan marine cores. Although equations for estimating organic and carbonate content appear independent of other sediment components, the opal equation is strongly dependent on carbonate content indicating that opal concentration is correlated to carbonate content. […]随着海洋岩心（marine cores）长度增加、采样间隔缩短，快速且低成本测定沉积物组成的需求日益凸显。本研究探讨了一种可用于评估海洋岩心组成变化的潜在实用技术——漫反射分光光度法（diffuse reflectance spectrophotometry）。我们分析了五组数据集的近紫外、可见光及近红外反射光谱，每组数据集均包含校正样本与测试样本：先通过多元线性回归（multiple linear regression）将校正样本的光谱与某一沉积物组分建立关联，随后利用测试样本对所得回归方程（即校正方程）进行评估。本次构建的校正方程可将光谱与多种沉积物组分相关联，包括大洋钻探计划（Ocean Drilling Program, ODP）847站位大西洋及东太平洋海隆的碳酸盐含量、大西洋及东太平洋海隆的有机碳含量，以及东太平洋海隆的蛋白石含量。各回归方程的相关系数介于0.97（大西洋碳酸盐）至0.99（ODP 847站位碳酸盐与蛋白石）之间，表明光谱变化与沉积物组成具有高度相关性。所有校正方程均包含大量来自短波可见光与长波近紫外波段的变量，这提示上述波段对专门用于扫描海洋岩心的设备尤为重要。尽管估算有机碳与碳酸盐含量的方程似乎不受其他沉积物组分的影响，但蛋白石含量的校正方程却强烈依赖于碳酸盐含量，表明蛋白石浓度与碳酸盐含量存在相关性。[…]