Ground magnetic survey at the Saurdal eclogite, Fjaler, Sogn og Fjordane

Abstract

This report presents results from a ground magnetic survey at the Saurdal eclogite at Saurdalsvatnet, Gjølangen, Fjaler in Sogn og Fjordane. The report also presents results from magnetic susceptibility measurements on drill-dust samples from the outcropping parts of the eclogite. The measurements aid in mapping the eclogite's westward extension. The Saurdalshaugen area appears with great variation in magnetic levels. One locality of similar magnetic signature is detected further west. The magnetic susceptibility measurements indicate a weak positive correlation between content of TiO2(total) and magnetic susceptibility . However, magnetic highs are no guarantee to great content of TiO2(total). Furthermore, analyses indicates that no magnetic level has great TiO2(rutile) content (i.e.> 3 %. In magnetic highs, however, the majority of samples (63 %) have a content of TiO2(rutile) between 1.5-3 %. Hence, it seems clear that magnetic highs can be of interest concerning TiO2(rutile) content. The relative content TiO2(rutile) (i.e. % TiO2(rutile)\/TiO2(total) seems to be greatest in low magnetic areas, which might be explained by alteration from medium magnetic ilmenite to low magnetic rutile.