Geochemistry of sediment core GeoB7920-2

The X-ray fluorescence (XRF) core scanner provides bulk-sediment chemistry data measured nondestructively at the split core sediment surface. Although this method is widely accepted, there is little known about the effects of physical properties such as density and water content on XRF core scanner data. Comparison of XRF scanner measurements from the sediment surface and dry powder samples of sediment core GeoB7920 indicates strongly reduced element intensities for the lighter elements Al and Si. We relate the lower element intensities of the measurements taken at the sediment surface to the amount of water in the sample volume analyzed by the XRF core scanner. The heavier elements K, Ca, Ti, and Fe remain relatively unaffected by the variation of any physical property within sediment core GeoB7920. Additionally, we successfully use the elemental intensity of Cl as a proxy for the seawater content in the sample volume analyzed by the XRF core scanner. […]

X射线荧光（XRF）核心扫描仪能够无损地测量在分割核心沉积物表面的大量沉积物化学数据。尽管此方法得到广泛认可，但对于诸如密度和含水量等物理性质对XRF核心扫描数据的影响，了解甚少。对沉积物核心GeoB7920的沉积物表面和干燥粉末样品进行的XRF扫描测量比较表明，较轻的元素铝（Al）和硅（Si）的元素强度显著降低。我们将沉积物表面测量的元素强度降低与XRF核心扫描仪分析的样品体积中的含水量联系起来。在沉积物核心GeoB7920中，较重的元素钾（K）、钙（Ca）、钛（Ti）和铁（Fe）对任何物理性质的变化影响相对较小。此外，我们成功地将氯（Cl）的元素强度作为XRF核心扫描仪分析的样品体积中海水含量的代理指标。