Borehole images now form a major part of the interpretation strategy for subsurface geological interpretation in a wide variety of scenarios. This volume attempts to document some case histories together with image acquisition and analysis techniques. It by no means covers the full breadth of the subject but is intended to provide a valuable source of information within one volume. We hope the broad spectrum of this text will encourage geologists to look outside their immediate areas of interest with the potential to learn from complementary work in other areas. <...>

Use of some petrologic diagrams applied to analyses of volcanic rocks is unnecessarily difficult due to lack of data for construction of discriminant lines between rock series. Coordinates are provided for sufficient points to enable accurate plotting of the boundary lines within seven diagrams, viz.: ( 1 ) TAS - total alkalies (Na20+K20) vs. SIO2; (2) K20 vs. SiO2; (3) AFM; (4) Jensen; (5) KTP - K20-TiO~-P205; (6)FMS- (FeO*/MgO) vs. SIO2; and (7) TAKTIP- K20/(Na20+K20) vs. TiOz/P2Os. Different versions of these boundaries are collated to indicate their variable position, and it is demonstrated that inter-laboratory analytical precision suffices to account for almost all of their spread on the TAS and K20 vs. SiO2 diagrams.

The recent accessibility of the collection of Dumortier, the complementary collects in the Bas-Beaujolais and in the Southern Provence, allow us to present the paleontological revision of the Toarcian and Lower Aalenian brachiopods of the Rhone basin (Bas-Beaujolais, Mont d'Or Lyonnais, La Verpilliere - Saint Quentin-Fallavier and Southern Provence). Then, the systematics of Dumortier is reactualized. The different species are again located in a more precised strati graphical framework. So, it is possible to deduce the biostratigraphy of Toarcian and Lower Aalenian brachiopods and then, to verify the value of the zonal succession established before (Almeras & ah, 1991)