Current research on ilmenite in the Egersund Province
Current research on ilmenite in the Egersund anorthositic Province is summarised in the present report. The first step in the prospecting for new ilmenite deposits is considered to be finished. This step contains pri- marily collection of raw data, such as airborne geophysical measurements, petrophysical studies, recognisance mapping, XRF-field-measurements, thin section studies and microprobe analyses. In addition, more specialised studies like gravimetry and detailed geochemical studies have been applied on the Tellnes deposit. The most promising Fe-Ti-occurrences are so far found to be those at Bakka and Mydland. Both areas contain ilmenite with favourable low amounts of Cr2O3 and MgO and very little or no hematite exsolution lamellae. Several of the airborne geophysical maps produced show interesting anomalies that can be used either in the prospecting and mapping of magnetite/ilmenite mineralisations or in the mapping of large scale geological structures. The magnetic maps show many interesting positive anomalies associated with Fe-Ti mineralised layered norites. Petrophysical studies have shown that the Egersund anorthositic Province has unusually high values of remanent magnetism that cause negative magnetic anomalies in parts of the area. The next step in the investigation is suggested to concentrate on (1) detailed geological mapping and sampling of the areas that at the present time seem to be the most promising regarding Cr and Mg contents in ilmenite, (2) a better understanding of the relationship between data obtained from whole rock chemistry, mineral chemistry and petrography, (3) continue the petrophysical work and start interpretations of the geophysical maps in order to identify new ilmenite deposits, (4) follow-up work on the ground.