RECONSTRUCTIONS OF CLIMATIC ZONATION AND SURFACE CIRCULATION PATTERNSIN THE INDIAN-OCEAN DURING NEOGENE BASED ON PLANKTONIC-FORAMINIFERA

Climatic zonation and some surface circulation patterns of the Indian Ocean were reconstructed for seven time intervals using DSDP/ODP data on planktonic foraminifera distribution in the Neogene sediments and n ew palinspastic schemes. There were two main warmings in the end of th e early Miocene and in the early Pliocene. Equatorial divergence and m onsoonal Indian upwelling persist from the early Miocene; Arabian-Soma lian upwelling can be traced at least from the middle Miocene. Distinc t latitudional climatic zonation became evident in the late Miocene, w hile during the early-middle Miocene east to west differences existed in the northern part of the ocean.