APPLICATION OF MULTIPLE DATA SETS TO STRUCTURAL STUDIES ON VARANGER PENINSULA, NORTHERN NORWAY

A synergistic approach has been used to define the lineament framework of the Varanger Peninsula, in particular the Trollfjord-Komagelv Faul t Zone, in northern Norway. This included the integration of remote se nsing, geophysical data sets, digital elevation data and geological fi eld observations. Digital image processing techniques have been applie d to the satellite images, raster aeromagnetic and gravity, and digita l elevation data. The Trollfjord-Komagelv Fault Zone divides the Varan ger Peninsula into two structurally distinct regions, one dominated by an allochthonous basin to the north, and an autochthonous/parautochth onous basin to the south; both contain metasedimentary rocks of Late P recambrian to Early Cambrian age. The fault zone is a major regional s trike-slip fault zone which can be traced to the northwest into offsho re basins in the southwestern Barents Sea; and to the south-east along the northern coast of the Kola Peninsula. This study has shown that t he Trollfjord-Komagelv Fault Zone is probably part of a regional NW-SE to WNW-ESE lineament system which is well defined in the Archaean to Proterozoic crystalline rocks to the south of the Varanger Peninsula. Gravity gradients and magnetic anomalies associated with these lineame nts indicate that they are deep-seated fractures; and in most places t hey are expressed as topographic lineaments.The kinematic analyses of conjugate shear fractures and fault-slip data suggest that the region has experienced multiple horizontal/subhorizontal compressional stress fields with different orientations, the NW-SE and NE-SW being most si gnificant, in time and space. Preliminary observations also suggest a shift of the sigma1 from horizontal/subhorizontal to vertical/subverti cal with time. The occurrences of these multiple tectonic events indic ate that the lineaments are composite shear zones and tensional fractu res which were probably affected by repeated movements of varying sens e in response to variations in the regional stress fields.