F.ishes have a unique evolutionary" history that stretches back in time more than 450 million yrears. They are incredibly ancient, older than the dinosaurs, and include the ancestors of all the limbed vertebrates living on land, even humans. Human evolution is rooted in fishes; and scientists have discovered traces of 360-million-ycar-old fossils of transitional aquatic creatures that had both gills and limbs.

The Bergell Alps offer not only a magnificent landscape with impressive mountains that attract many tourists, but also they document a unique geological history, first explored by Bernhard Studer (1851) and since then studied and documented in many publications. In this book, we try to connect visitors with scientific curiosity with remarkable geological features observed in the Bergell Alps, such as a young granite that intrudes into an older stack of nappes (thrust sheets) that represent the European continental plate at the base overthrust by the African plate, causing gradients in temperature and pressure that can be explored by looking at outcrops of rocks in the field. 

The Cadia Ridgeway deposit is one of a group of porphyry-style deposits discovered since 1992 by Newcrest geologists at Cadia 20 kms south of Orange in the central tablelands of New South Wales, Australia. The Ridgeway deposit lies 500m below the surface, 3 kms north-west of the Cadia Hill open cut mine, and was discovered in November 1996. It is notably rich in Au with an inferred and indicated resource of 44 Mt at 2.6 g/t Au and 0.82% Cu, and is under development as an underground mining operation. <...>

Zoning patterns and zoning truncations in metamorphic minerals in a granodioritic orthogneiss indicate that strain and S-C fabrics in these rocks were produced by dissolution, precipitation, and replacement processes, even at epidote-amphibolite fades metamorphic conditions. The metamorphic fabric is defined by alternating layers and folia dominated by quartz, feldspars, and biotite + epidote. Zoning patterns in most metamorphic plagioclase, orthoclase, epidote, and sphene are truncated at boundaries normal to the shortening direction, suggesting dissolution. Interfaces of relict igneous orthoclase phenocrysts that face the shortening direction are embayed and replaced by biotite, epidote, and myrmekitic intergrowths of plagioclase and quartz. Metamorphic plagioclase grains are also replaced by epidote. We interpret these microstractures to reflect strain-enhanced dissolution. The cores of many grains show asymmetric overgrowths with at least two generations of beards, all oriented on the ends of grains that face the extension direction. We interpret these textures to reflect precipitation of components dissolved by deformation-enhanced dissolution. While biotite and quartz probably deformed by dislocation creep, the overall deformation was accommodated by dissolution perpendicular to the shortening direction, and precipitation parallel to it. These chemical processes must have been activated at lower stresses than the dislocation creep predicted from extrapolations of data from experiments in dry rocks. Thus wet crust is likely to be weaker than calculated from these experimental studies