New results of studies on the fossils in the Lower Cambrian sediment deposit of the Söderfjärden Basin

Fossils Mickwitzia monilifera and olenellid trilobite fragments are found in the greenish grey shale in the lower sediment formation of Söderfjärden at a depth of 237.8 and 278.05 m. Microfossils (acritarchs) Archaeodiscina umbonulata, Baltisphaeridium cerinium, Granomarginata squamacea, Lophosphaeridium tentativum, Tasmanites bobrowskii, T. piritaensis were also observed in the lower part of the Söderfjärden sedimentary formation. In this lower intersection the microfossil genera resemble those in the upper sediment formation. Only one new species, Dictyotidium bottnicum, is described in the lower portion of the formation. The occurrence of the fossils and microfossils in the Söderfärden sediment formation suggest Lower Cambrian sedimantation.