| The seismic horizons have been calibrated using biostratigraphic and lithological data from exploration boreholes in the UK and Faroes sectors. |
| Numerous regional schemes rationalizing the nomenclatural stratigraphy of the critical time have been developed, and a variety of biostratigraphic zonations evolved. |
| Surely, these are not the most adequate sources for precise biostratigraphic data neglecting other results attained by many authors recently and long ago. |
| Their biostratigraphic relationships with coeval assemblages from Patagonia deserve more detailed analysis in the future. |
| To assign the interbedded sedimentary strata to the correct system it is, however, necessary to incorporate biostratigraphic and petrographic data. |
| However, the lack of consistently good quality biostratigraphic data makes the accurate picking of biozone tops and bases uncertain in most North Sea well sections. |
