An updated correlation of the Silurian strata in Estonia

The correlation of the Silurian succession of Estonia with the global standard has long been considered reliable. However, new information, particularly on the distribution of microfossils, has changed our understanding of the Silurian stratigraphy in the region. Recent palaeontological and geochemical data suggest that: the lower part of the Juuru Regional Stage (RS) is of Hirnantian age; the age of the base of the Raikküla RS in terms of global chronostratigraphy remains problematic; the Aeronian–Telychian boundary correlates with a level in the middle of the Rumba Formation (Fm); the base of the Adavere RS is of latest Aeronian age; the former Riksu Fm is considered to be the proximal, older part of the Sõrve Fm; the traditional lower boundary of the Jaagarahu RS is diachronous, and the closest biostratigraphic horizon that could be used is the first appearance datum of Jeppssonia sagitta rhenana; the Wenlock–Ludlow boundary correlates with a level in the upper Rootsiküla RS; the base of the Paadla RS corresponds to a level in the upper Gorstian, in the lower(?) Phlebolepis ornata Vertebrate Biozone; the Sauvere and Himmiste beds of the Paadla Fm are of late Gorstian age, and the Uduvere Beds are of early Ludfordian age, corresponding to part of the Ancoradella ploeckensis Conodont Biozone; identifying the Ludlow–Přídolí boundary in the Estonian succession is problematic, lacking reliable criteria at present. With these amendments, we present an updated regional correlation scheme drawn on a regular time scale for the first time. A problem that needs to be addressed in the future is providing better biostratigraphic definitions for the bases of regional stages.