TRANSALP—A transect through a young collisional orogen: Introduction

TRANSALP is a multidisciplinary and international research programme for investigating the deep structure and evolution of the Eastern Alps (Fig. 1) as a paradigmatic example for mountain building by continent–continent collision. The Alps as the youngest and highest mountain range in Europe have always been a challenge for geoscientists, and have played a key role in the development of new concepts and theories of mountain building (e.g. Termier, 1904, Ampferer, 1906, Argand, 1924, Dal Piaz, 1934, Dewey and Bird, 1970, Laubscher, 1970 and Oxburgh, 1972). While our former understanding was mainly based on geology and low resolution geophysical methods such as gravimetry and deep seismic soundings (DSS) with wide-angle and refraction seismics, more recently remarkable progress has been gained in the Western and Central Alps by applying the high-resolution technology of deep seismic reflection profiling (Roure et al., 1990 and Pfiffner et al., 1997), adapted from exploration techniques used in oil and gas industry.