Distribution of Fe-Ti oxide minerals in the Ørsland, Bakka-Krune and Einebakka area of the Bjerkreim-Sokndal layered norite, Rogaland

Abstract

Geological mapping in scale 1:5000 in the Sokndal Lobe of the Bjerkreim-Sokndal layered norite intrusion has confirmed that cyclic unit no.IV of the magmatic stratigraphy comprise a high density of Fe-Ti oxide rich layers. The area naturally divides in the Ørsland, Bakka-Krune and Einebakka areas which indi- vidually are shaped as mega-lenses connested to each other via more narrow zones. However, seen together they comprise an open synfom dipping 40o to the west. Zones with a high desity of Fe-Ti oxide rich layers has a patchy distri- bution exhibiting thicknesses from 1 to 120 meters and a limited extent along strike. The Bakka-Krune area has the largest size but the most patchy appearance of Fe-Ti oxides which makes it very difficult to evaluate the total resources. The Einebakka area comprise the largest continuous zone of Fe-Ti oxide rich layers with a documented strike length of 450 meters and thicknesses between 20 and 120 meters.