The Bjerkreim-Sokndal Layered Intrusion
a significant resource for apatite, ilmenite and magnetite
Rogaland CountyHere we present information on a promising future resource of apatite, ilmenite and magnetite. The resource is hosted within a layered intrusion – The Bjerkreim-Sokndal Intrusion in Southwestern Norway.
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Click on the image to see a larger map or download it as pdf (3,1 Mb).
A: Location of the Bjerkreim-Sokndal Layered Intrusion in southwestern Norway B: The geology of the Rogaland Anorthosite Province draped on the topography. The Bjerkreim-Sokndal Intrusion is shown in red and greenish colours while anorthosites are shown in blue. |
The work we present here is focused on the Bjerkreim-lobe of the intrusion. Based on more than 200 samples from 17 localities we have delimited four main targets making a total of 1.1 km2 or 273 million tons of probable ore resource (to 100 m depth). In these four targets the amounts of value minerals makes a total of 30 % of the noritic host rock, containing on average 8.7 % apatite, 12.9 % ilmenite and 8.2 % magnetite. The apatite has a low content of heavy metals and the ilmenite is relatively pure with on average 1.5 % MgO. The magnetite is a relatively vanadium-rich magnetite with on average 0.9 % V2O3.
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Click on the image to see a larger image or download it as pdf (1.8 Mb).
An important contact is exposed in the hill of Storeknuten. This contact is between two major geological units in the Bjerkreim-Sokndal Layered Intrusion (MCUIII and MCUIV). To the left of the arrows the vegetated hills represent apatite-magnetite- and ilmenite-rich norite at the top of MCUIII. To the right the rocks consist of norite and troctolite without apatite and magnetite at the base of MCUIV. This contact can be mapped as a marker horizon systematically throughout the Bjerkreim-lobe of the intrusion. (MCU = megacyclic unit) Photo: G. Meyer, 2000, NGU |