Upper Pliensbachian-Middle Toarcian foraminiferal assemblages at Camino Section (Basque-Cantabrian Basin, Spain)

Abstract

Boreal foraminiferal faunas have been recorded in the Upper Pliensbachian-Middle Toarcian at Camino Section (Western Sector of the Basque-Cantabrian Basin, Spain). The results reveal stepwise extinction, replacement and renewal events along the Pliensbachian-Toarcian transition. The extinction of typical long-ranging Lower Jurassic foraminiferal species takes place mainly in the Tenuicostatum Zone of the Toarcian. Besides this, the most significant renewal event occurs in the Serpentinum Zone with the first appearance of the genus Citharina represented by various species. Typical Lower Toarcian species are recorded in the Tenuicostatum Zone both in the Paltum and Semicelatum Subzones.