THE NORTH ATLANTIC IGNEOUS PROVINCE
Deposits of volcanic ash in the Danish Basin

Lotte Melchior Larsen in collaboration with Asger Ken Pedersen (Univ. Copenhagen) and Godfrey Fitton (Univ. Edinburgh).

The Danish Paleogene clays contain an interval, equivalent to the Sele and Balder Formations in the North Sea, with about 180 layers of volcanic ash. Geochemical investigations have resulted in the identification of possible source areas for the ashes, changing from centres on the NW European shelf and in East Greenland to the position of Proto-Iceland in the central opening rift.
The onset of the cataclysmic hydroclastic eruptions that produced the Balder Formation and the 'positive' ash series in Denmark is probably coupled to the demise of the formation of the lava plateau in East Greenland, when the mantle areas of extremely high magma production (the Iceland plume) moved from beneath East Greenland into the sea-covered opening rift, thus switching the bulk volcanism from effusive to explosive.

Publications
Larsen, L. M., Fitton, J.G. & Pedersen, A.K. 2003: Palaogene volcanic ash layers in the Danish Basin: compositions and source areas in the North Atlantic Igneous Province. Lithos 71, 47–80.