Geological History for the Larvikite by Magne Marthinsen

The history of larvikite goes back a long time. The larvikite is deposited in the area history of the earth called Permian. The larvikite is a rock which origin from a melt that was initiated on the border between the earth’s crust and the viscose mantel, and later forced itself through the crust. Deep down the melt it had a lower density than the crust, and the melt started to ascend through weak zones in the crust created by movements between the continental plates. On the way up the hot intrusion partly melted the rocks it forced itself through, and eventually got the same density as the crust. The shape of this kind of intrusion will be as a mushroom. The intrusion is thought to have been deposited at several kms depth.