Scientific outline and general schedule (provisional):
The excursion will take place from 31 July to 5 August 2008.
Day 0: Arrive at Stavanger airport. Transport to Egersund. Evening presentation of the Rogaland Anorthosite Province.
|Day 1: Highly deformed and metamorphosed gneissic envelope to the anorthosite province. Anorthosite and leuconorite of the Egersund-Ogna anorthosite massif. Features include orthopyroxene and plagioclase megacrysts, large and diverse xenoliths and marginal foliations. In some areas plagioclases show labradorescence; these rocks are used commercially. The margin of the massif was deformed as a result of diapirism and is strongly foliated. There are several types of alteration.
Day 2: The Bjerkreim-Sokndal layered intrusion. We will examine various features of the >7km-thick Layered Series, including the cumulate stratigraphy and anorthositic inclusions. Modal layering is extremely well-developed and shows local evidence of magmatic current activity and also structures formed by the impact of xenoliths on the magma chamber floor. We will see evidence for major events of magma replenishment at the base of Megacyclic Units (MCU). These include a persistent layer of sulphide-bearing ilmenite orthopyroxenite (a result of magma-mixing at the base of an MCU), abrupt reversals to primitive lithologies, and the development of primitive troctolitic units near the bases of MCUs.
Day 3: The Bjerkreim-Sokndal layered intrusion – the evolved rocks. The intrusion accommodates the entire range of anorthosite-kindred lithologies. Anorthosite, troctolite, leuconorite, norite and gabbronorite will be seen on Day 2. On Day 3 we will visit the more evolved lithologies: jotunite, mangerite, quartz mangerite and charnockite. There are also many types of inclusions. The Koldal minor intrusion cuts across the foliated margin of the Egersund-Ogna anorthosite massif and shows many interesting features in a small area. Fe-Ti mineralization at Kydlandsvatn will also be examined.
Helleren Photo: Magma Geopark
Day 4: The southern (Sokndal) part of the Bjerkreim-Sokndal intrusion and the Åna-Sira anorthosite massif. There is extensive Fe-Ti mineralization in this area and we will visit the old Blåfjell ilmenite mine, the Storgangen ilmenite mine, and the active ilmenite mine at Tellnes.
Day 5: Transport to Stavanger airport. Fly to Oslo.