Peep Männik avaldas artikli ajakirja Estonian Journal of Earth Sciences 2017. a avanumbris (mõjufaktor IF 0,732).
Männik, M. 2017. Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia. Estonian Journal of Earth Sciences 66, 1-12.
Conodonts from the type region of the Oandu
Stage (Katian, Upper Ordovician) in NE Estonia were studied. Here, the lower boundary of the stage corresponds to a discontinuity surface at the base of the Hirmuse Formation and, in conodont succession, is marked by the disappearance of Semiacontiodus sp. and Besselodus? sp. The most characteristic taxa of the Oandu Stage are Phragmodus undatus, Icriodella cf. superba and Plectodina sp., which are rare or missing below and above this stratigraphic interval in Estonia. The comparison of conodont faunas from North and South Estonia suggests that the strata in North Estonia correspond to the upper part of the Oandu Stage only as identified in sections in South Estonia. However, the position of the lower boundary of the stage in South Estonia is highly problematic. The boundary between the Amorphognathus tvaerensis and A. superbus conodont zones in Estonia lies within the (upper) Oandu Stage.