Sedimentological and palaeobotanical investigations of a Miocene sequence at Lavsbjerg, Central Jutland, Denmark

Miocene deposits from a 120 m deep boring in Central Jutland have been analysed for sedimentological and palaeobotanical characteristics. Primary minerals are largely unaltered in the major part of the sequence and clay mineral transformation as well as dissolution of unstable heavy-minerals have only been recognized between and immediately below the brown-coal sequence. The depositional environment is interpreted as being a shallow sea into which a large delta was constructed. The delta plain was subsequently covered by swamp vegetation from where acid waters penetrated the deltaic sequence and caused mineralogical changes.

Part of the Miocene sequence yielded abundant Carboniferous and a few Mesozoic megaspores. The latter may be derived from the Fennoscandian Borderzone whereas the Carboniferous material most likely was derived from more distant sources. Petrographical characters of these spores point to a British origin, which may strongly indicate that the megaspores were transported by currents in the Sea.