SEISMOTECTONICS AND NEO IN FINNMARK, KOLA-PENINSULA AND THE SOUTHERN BARENTS SEA .1. GEOLOGICAL AND NEOTECTONIC FRAMEWORK

As a background for assessing the seismo- and neotectonics of the Finn mark-Kola Peninsula region, emphasis has been directed towards the lin eament framework, involving a careful examination of digital Landsat-T M imagery integrated with a variety of data-sets ranging from geophysi cs and digital elevation models to microtectonics. Based on a detailed field-structural control of many of the multiphase lineaments in this 70,000 km(2) area of the northeastern part of the Fennoscandian Shiel d, as well as microscopic investigation of the fault mylonites and bre ccias, five principal lineament sets were distinguished. Of the NW-SE polyphasal megafractures, the Murmansk Shear Zone carries geological a nd isotopic evidence of an Archaean tectonothermal history, and demarc ates an important terrane boundary. Lineaments, irrespective of their trends, were classified according to their significance in the regiona l-geological framework. Some lineaments are clearly associated with gr avity and aeromagnetic anomalies and probably extend to deep crustal l evels. Quite a few of the prominent faults within lineament zones were reactivated in post-glacial times. In one area in Finnmark, core dril ling through a SE-dipping post-glacial reverse-fault has confirmed its listric shape at depth. Earthquake focal mechanisms for this same fau lt are presented in the second part of this dual contribution.