ABSTRACT
Silurian brachiopod communities from three cored boreholes in the Baltic Basin were discriminated by quantitative taxon analysis, and their distribution was compared to carbonate and siliciclastic rock content. From late Llandovery to early Ludlow time, terrigenous sediments dominated in this part of the Baltic Basin, and brachiopod communities tolerant to siliciclastic, dysaerobic settings developed. With reduced siliciclastic input and basin shallowing in the early Ludlow, these communities were replaced by Atrypa and Spirigerina communities adapted to aerobic conditions and reduced siliciclastic supply. In the late Ludlow and Pridoli, carbonate sedimentation prevailed and only four moderate to low diversity brachiopod communities existed. Results of this study are similar to the those obtained from evaluating the relationship between these communities and whole rock chemical analyses (for Si, Al, Ti, Fe, Ca, Mg-oxides). Whole rock standard analyses may thus be used for general quantitative evaluation of the association between sedimentation and brachiopod asemblages.
