Neogene Radiolarians from the Eastern Tropical Pacific and Caribbean, Deep Sea Drilling Project Leg 68

Abstract

Two sites were drilled with the hydraulic piston corer on Leg 68. Site 502, in the western Caribbean, contained radiolarians only in the uppermost (Quaternary) and lowermost (upper Miocene) cores. At Site 503, in the eastern Pacific, radiolarians were common and well preserved throughout the sequence, which terminated in the upper Miocene. The sequence of radiolarian events at Site 503 correlates well with that at Site 495, Leg 67, and the few discrepancies are resolved with an index of reliability. A detailed study of morphological changes during the evolution of Didymocyrtis spp. in the undisturbed sequence from Site 503 shows more departures from a simple rectilinear tendency than had been known from previous, coarser investigations.