39. DATA REPORT: RESULTS OF GEOCHEMICAL WELL LOGGING IN THE IZU-BONEV FOREARC BASIN, SITES 782 AND 786, LEG 1251

Geochemical well logs were obtained both in sediments and in basalts at Sites 782 and 786 during Leg 125. Corrections have been applied to these logs to account for variations in hole size, interference of drilling fluids, and drill-pipe effects. Calcium carbonate and oxide weight percentages have been calculated from the processed logs and have been compared to the available core measurements. The log-derived carbonate curve is compared to shipboard CaCO3 measurements in Hole 782B and in the upper portion of Hole 786B, and the two show reasonable agreement. Instrumental neutron activation analysis measurements have been compared to the natural gamma-ray measurements in Hole 786B; poor agreement exists between the log and core data for Th and U, most likely due to the very low concentration of these two elements. The numerous X-ray fluorescence measurements, performed for the basement section of Hole 786B, show excellent agreement with the logs, with the exception of MgO in the Mg-rich basalt units.