Magmatic underplating/intrusions

Extensive magmatic activity took place in the mid Norway and the Barents Sea area related to the Early Cenozoic rifting. Igneous intrusions, sills and dykes affect the thermal regime of the sediments. To understand the maturation history of hydrocarbons in this area, it is of utmost importance to model the thermal effects of sill intrusion numerically. It is shown that sill complexes could affect the overall basin temperature and maturity significantly.

Sill intrusions 

Modelled maturity in a basin with magmatic sill intrusions; orange/red colors show areas of high transformation ratio. The effect of the magmatic intrusions are significant; cf. Fjeldskaar et al. (2008) for more details.

 

Magmatic underplating

In parts of the marginal areas of mid Norway a high-velocity and high-density layer  (LCB) is inferred below the crystalline basement. These high velocity bodies have been identified beneath the eastern Vøring Basin and Møre Basin, beneath the Nyk High and Træna Basin  and beneath the Horda Platform. The figure below shows the modelled temperature effect of a possible magmatic underplating; cf. Fjeldskaar et al. (2009) for more details.

Modelled temperature effect of a possible magmatic underplating

 

Fjeldskaar, W., Helset, H.M., Johansen, H., Grunnaleite, and I., Horstad, I., 2008.
Thermal modeling of magmatic intrusions in the Gjallar Ridge, Norwegian Sea and the consequences on vitrinite reflectance and hydrocarbon maturation.
Basin Research 20, 143-159. doi: 10.1111/j.1365-2117.2007.00347.