Abstract
During Ocean Drilling Program Leg 134, a mixed sequence of volcaniclastic and carbonate sediments was cored together with basaltic breccias and a single basalt sill in Hole 833B. In this study, data from Schlumberger's Geochemical Logging Tool, together with physical property logs, characterise part of the section and establish a complete log-derived lithostratigraphy. The major transition between the sedimentary rocks and a basaltic sill at 830 mbsf (metres below sea floor) is clearly seen as well as the distinction between the silicate-rich sediments and the carbonate-rich part of the section. The transition between the volcanic sandstone interbedded with basaltic and sed-lithic breccia of Unit III, and the volcanic sandstone of Unit IV is clearly marked by the physical property logs. The accuracy of the logging data was evaluated and discussed with an improved log versus core correlation. The cluster analysis of the complete data set shows a correlation with the data provided by the mechanical caliper device, which in turn indicates the quality of the borehole.