Original paper

The sauzei and 'so called' sowerbyi Zones of the Lower Bajocian

Parsons, Colin F.


The sauzei and sowerbyi Zones are discussed in the light of new evidence from Normandy, (France), Schwabia, (South Germany) and Southern England. The sauzei Zone is re-interpreted as a 'fauni-zone'. The sowerbyi Zone is rejected and evidence given for its replacement by the laeviuscula Zone, (HAUG, 1894). It is shown that the subzonal divisions of the Sowerbyi Zone were based on incorrect stratigraphic evidence. The laeviuscula Zone is subdivided into a redefined laeviuscula Subzone (Senior objective synonym or trigonalis) and an ovalis subzone; the discites Subzone being elevated to full zonal rank. A detailed analysis is given of the ammonite faunas of Southern England, from the sauzei to concavum Zones, as well as a brief summary of the correlation of equivalent horizons in Normandy and Schwabia.