Latest Sandbian brachiopods and chitinozoan biostratigraphy in North Estonia

Abstract

The latest Sandbian brachiopods and chitinozoans were studied in the Kõrgessaare and Haapsalu drill cores of Estonia. The brachiopod fauna shows a gradual renewal through the Keila Regional Stage ( RS ) , differently from the rather persistent association of chitinozoans. An exception is the uppermost part of the stage, which differs in two sections in the taxonomic composition of chitinozoans and the occurrence of two species-level taxa of the Dalmanella kegelensis brachiopod group. D. kegelensis sensu lato has been considered an index taxon of the biozone in the Keila RS. It links the brachiopod faunas of North Estonia to those in NW Russia. In the latter region, the dolomitic and siliciclastic lagoonal and peritidal deposits overlying the strata with brachiopods of the D. kegelensis group are considered the youngest part of the Keila RS.