The analysis of FMS images complement the observations made of cores. This analysis yields the dip direction of structural events and is not dependent on core recovery. However, it is limited to the depth range outside the two washout zones at 223-234 and 241-247 mbsf.
Planar structures correspond to sinusoids on the images that were mapped with the Schlumberger Geoframe software. They were interpreted either as beds, broken into two categories (bed 1 for best determinations and bed 2 for poorer determinations), fractures (frac 2 for the few faults with reverse offset and frac 1 for the others), or undetermined features (labeled unkn) (Fig. F4). The analysis is usually done on the dynamic image where the corresponding sinusoids are shown (Figs. AF1, F5, F6, F7, F8, F9, F10). The tadpole plot indicates their dip and dip direction. As this hole presents a high density of events, only clearly visible features have been mapped. Several hundreds of unclear features (maybe not planar or present on only one or two pads or impossible to classify in any of the groups, for example) are also present but have not been selected for this study.
This analysis has led to the determination of 121 fractures (frac 1), three reverse faults (frac 2), 447 beds of good quality (bed 1), 41 beds of poorer quality (bed 2), and three clear but unclassified events (unkn). The depth dependence of the structural measurements is represented on the tadpole plot of the whole borehole images (Fig. F4). The orientation of these measurements is displayed on stereographic projection and on strike and dip histograms (Figs. F11, F12, F13).