Calcareous nannofossils from the Japan Trench upper slope, Leg 56, Deep Sea Drilling Project.

Abstract

Calcareous nannofossils were only encountered at Site 435 and yield fairly diverse early and late Pliocene assemblages. The section shows considerable reworking, however. 3-5 biostratigraphic datum events provide a reasonable biochronology. The datums range from about 3.3 Ma in Core 11 to about 1.8 Ma in Core 3. Paleobiogeographic data indicate relatively stable and warm climatic conditions in this area in the early Pliocene, becoming more unstable in the late Pliocene when the cosmopolitan species become dominant.-Authors