| details |
Tremadocian |
Arenigian |
Spain |
Wolf,R. Acritarchs of the Tremadocian Keltiberien (northeast Spain). |
1980 |
| details |
Tremadocian |
|
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 |
Late Tremadocian |
Early Arenigian |
England(Lancashire) |
Molyneux,S.G. et al. The age of the Watch Hill Grits, (Ordovician), English Lake District; Structural and palaeogeographical implications. |
1988 |
| details |
Tremadocian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |