SITE 693 AND CORE 8R 12 1.8 CURRENT CONDITIONS 14 METHODS 29 2.1 X-RAY FLUORESCENCE CORE SCANNING 29 2.2 PRINCIPAL COMPONENTS ANALYSIS 30 2.3 PARTICLE SIZE ANALYSIS 31 2.4 CHARACTERIZING IRD 32 RESULTS 35 3.1 XRF CORE SCANNING 35 3.2 PRINCIPAL COMPONENTS ANALYSIS 36 3.3 GRAIN SIZE DISTRIBUTION 38 3.4 IRD GRAIN COUNTS 39 DISCUSSION 54 4.1 PCA 54 4.2 IRD, BIOSILICA, AND XRF ELEMENTAL DATA 55 4.3 BIOSILICA AND FE FERTILIZATION 58 CONCLUSION 64