Nature of boundaries between crystallin basement and sedimentary rocks in the Møre-Trøndelag coastal area - reinterpretation based on digitized sparker lines, 2D seismic and detailed bathymetry

Abstract

This report is part of the SPARDIG project. The main aim of the project has been to transform oldanalogue sparker records from the Nonvegian continental shelf into SEG-Y format. Off Møre andTrøndelag, these data were interpreted together with 2D seismic lines and bathymetric data tostudy the geology of the transition zone between crystalline basement and the overlyingsedimentary rocks.The objective of the scientific part of the project has been to utilize the new data set to make anupdated geological map. We were able to classify the basement-sediment contact based on thecontact relationships and to update the map accordingly. Several new faults were mapped basedon detailed bathymetry and the seismic data.Exposures of weathered basement at the seafloor and juxtaposition of basement and sedimentsacross inherited faults were observed up to several kilometers along strike. These relationshipsprovide important links to the deeper structure and stratigraphy of the Mid-Non\u00A1uegian margin. Asuite of triangular Quaternary basins observed along the basement-sediment contact in the lllørearea highlights the need to investigate furlher the possibility of Quaternary fault reactivation.