Jurassic micropaleontology of the Grand Banks

Abstract

Key-words: Jurassic - Micropaleontology - Foraminifera - Grand Banks Jurassic foraminifera in the marine deposits (up to 3 km thick) of the Grand Banks of Newfoundland define eight biostratigraphic zones of Pliensbachian through Tithonian age. Jurassic marine deposition (- 4 cm/1000y) kept pace with subsidence resulting in a relatively continuous, shallow marine sedimentation pattern. Central Grand Banks subsidence ceased in Late Jurassic time and the area became emergent with erosion taking place until Albian time. Grand Banks Jurassic foraminiferal assemblages are of a distinctly Old World affinity reflecting the contracted early Atlantic paleogeography. Compositional differences with Portuguese Middle-Late Jurassic microfauna are probably related to differences in depositional history of the Portuguese and Grand Banks Basin.