Destructive diagenesis of carbonate sediments in the eastern Skagerrak, North Sea

Marine diagenesis of carbonate sediments in shallow waters in the eastern Skagerrak is characterized by dissolution and breakdown. The processes leave a diagnostic petrographic record, consisting of etch patterns on grain surfaces, partial dissolution of fabrics in the interior of grains, and finally, complete structural breakdown of biogenic carbonate constituents.

Because of the structural breakdown, great numbers of calcareous organisms are lost from the fossil record. A residual amount of their microscopic structural elements occurs as a very typical lime-mud fraction in the sediments.

Dissolution of carbonate constituents seems to be an ordinary ingredient in the normal, healthy marine environment in the eastern Skagerrak. Spot-checks indicate the presence of dissolution also in the Kattegat and the brackish Baltic Sea—in total, an area of 450,000 km². This is supposed to be the largest occurrence of carbonate dissolution so far reported from shallow waters.