Stratigraphy of the Late Middle Eocene to Early Oligocene in the Bath Cliff Section, Barbados, West Indies

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Abstract
Changes in fauna and flora across the Eocene Oligocene boundary are documented in an expanded section of indurated deep sea oozes and ash beds deposited close to the CCD [carbonate compensation depth] and now exposed at Bath Cliff, Barbados. A sedimentation rate of 27 m/million yr for the Late Eocene is calculated. The spread of events through time does not suggest any catastrophe at the boundary. The last occurrence of disc-shaped discosaters (CP 15/CP 16 Zone boundary) occurs before the last occurrence of Hantkenina, which is taken to represent the epoch boundary. The last occurrence of Turborotalia cerroazulensis s.l. occurs slightly before the boundary; the Cryptoprora ornata/Theocyrtis tuberosa radiolarian Zone boundary occurs slightly after it. The Thyrsocyrtis bromia radiolarian Zone of the Late Eocene has been replaced by 3 new zones, from top to bottom: C. ornata Zone, Calocyclas bandyca Zone, and "Carpocanistrum" azyx Zone. A microtektite horizon occurs in the Cryptoprora ornata Zone slightly < 1 million yr before the epoch boundary. In the basal Oligocene a sudden enrichment of 18O in Oridorsalis umbonatus suggests a drop in bottom water temperature of 5.degree.-6.degree. C.