Geochemical results from wireline logs in the Celebes Sea, Sites 767 and 770 of Leg 124

Geochemical well logs were obtained at ODP Sites 767 and 770 in the Celebes Sea. The log data obtained at sea have been corrected for borehole size changes, the effects of drilling fluids, and logging-speed variations. The processed logs are then used to calculate the amounts of the three major radioactive elements (Th, U, and K) and the dry weight percentages of oxides every 0.1524 m throughout the logged intervals. Numerous oxide core measurements were made for Site 767 and for the basement section of Site 770. Core and log measurements of CaO, A12O3, FeO*, K2O, and TiO2 agree well. At both sites, however, the log-derived SiO2 is higher than that measured on cores. The discrepancy is due to the fact that MgO or Na2O could not be calculated from the logs, causing each of the elements measured by the geochemical tool to be slightly high, an effect that is most apparent in SiO2 because it makes up the greatest portion of the rock-forming elements.