| details |
Tremadocian |
Early Arenigian |
Spain |
Wolf,R. The Lower and Upper boundary of the Ordovician System of some selected regions, (Celtiberia, Eastern Sierra Morena) in Spain. Part 1: The Lower Ordovician Sequence of Celtiberia. |
1980 |
| details |
Tremadocian |
|
France(Lot-et-Garonne) |
Baudelot,S. et al. Paleozoic basins hidden under the Aquitaine: Micropaleontological study of core collected during petroleum investigations. (In: Program of deep geology of France first phase of investigation-1983-1984) |
1984 |
| details |
Early Tremadocian |
|
Belgium |
Martin,F. The acritarchs from the Belgian Ordovician and Silurian. Determination and stratigraphic value. |
1968 |
| details |
Late Cambrian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |