The present volume is the result of activities within the scientific programme "Response of the Earth System to Impact Processes" (IMP ACT) of the European Science Foundation (ESF). The ESF is an association of 67 national member organisations devoted to scientific research in 24 European countries. The IMPACT programme is aimed at understanding meteorite impact processes and their effects on the Earth System. Launched in 1998 for a duration of 5 years, the programme is now supported by 15 ESF membership countries. The programme of meteorite impact research and operates through deals with all aspects workshops, exchange programs, and short courses. The 4th IMPACT programme workshop "Meteorite Impacts in Precambrian Shields" took place on May 24-28, 2000, in Lappajarvi, western Finland. A total of 84 scientists from 19 countries from Europe, North America, and Africa participated in the workshop. During the workshop, 43 oral, 31 poster, and several video presentations were made. An exhibition of impactite rocks from Finnish craters and two excursions were organised. The excursion to impact melt rock outcrops of the Lappajarvi structure took place during the workshop. The Karikkoselka and Saaksjarvi impact structures in south-central Finland were visited during the post-meeting excursion.
