Reflection seismic imaging of the end-glacial Pärvie Fault system, northern Sweden

Abstract

Reflection seismic data were acquired along a c. 23. km long profile over the Pärvie Fault system with a nominal receiver and source spacing of 20. m. An hydraulic breaking hammer was used as a source, generating signals with a penetration depth of about 5-6. km. Steeply dipping reflections from the end-glacial faults are observed, as well as sub-horizontal reflections. The location and orientation of the reflections from the faults agree well with surface geological observations of fault geometries. Reflections from a potential fourth end-glacial fault is observed further to the east along the profile. The more sub-horizontal reflections may originate from gabbroic bodies within the granitic basement or from deeper lying greenstones. Our results indicate that the end-glacial faults dip at moderate to steep dips down to at least 2-3. km depth, and possibly continue at this dip to depths of 6. km. This result has significant implications for determining the state of stress required to activate the faults in the past and in the future. © 2009 Elsevier B.V.