The Lower Didymograptus Shales of the Flagabro Drilling Core

In the core section described the basal strata are very poor in graptolites. On the other hand, they have yielded trilobite species characteristic of the Lower Planilimbata Limestone. Most part of these shales have been included with the zone of Tetragraptus phyllograptoides. The zone of Didymograptus balticus contains a rich graptolite fauna described by Törnquist. In the shales with Phyllograptus densus the Norwegian zone of P. angustifolius elongatus is well developed, and has yielded several graptolite forms new to Sweden. The top strata of the Lower Didymograptus Shales (with Isograptus gibberulus, etc.) are not represented in the core. They have been exposed through diggings carried out at the Flagabro rivulet. Preliminary notes on the graptolite fauna of these shales are added to the description of the core.