WHAT LEVEL OF RESOLUTION IS ATTAINABLE IN A DEEP-SEA CORE - RESULTS OF A SPECTROPHOTOMETER STUDY

A Minolta CM-2022 spectrophotometer has been used to characterize down core fluctuations in sediment lightness and color in core NEAP15K, a 7 -m core collected from the northeast Atlantic Ocean. High-resolution d ata series, measured using a 4-mm-diameter measurement spot and a l-cm sampling interval, were generated along two independent tracks down t he core to investigate the statistical significance of fluctuations ac ross the 2-20-cm-depth range. This small-scale variability is characte rized by abrupt changes in the lightness and color of the sediment tha t are several orders of magnitude greater than the instrumental precis ion. Our results establish that significant information is preserved a t the l-cm scale in spite of bioturbation effects. These findings demo nstrate that high-resolution studies using conventional paleoclimatic proxies have the potential to recover meaningful century-scale climate records in regions of the ocean where sedimentation rates exceed 10 c m per thousand years. The coherency of these downcore records also imp lies that the spectrophotometer is a powerful instrument for establish ing precise centimeter-scale stratigraphic correlations between cores.