Radiolarian assemblages of ODP Leg 117 sites

Sparse faunas were recovered from five additional sites on the Oman margin and one site on the Indus Fan. Detailed range charts and biozonations are presented for most sites.

The radiolarian assemblages are peculiar in that numerous common tropical forms, some of which are biomarkers, are absent or very rare. In addition, some species not usually found in tropical assemblages are present. These forms, indicative of up welling conditions, fall into three categories: (1) endemic upwelling: species endemic to upwelling and not previously described from the Indian Ocean; (2) displaced temperate: temperate forms not usually found in tropical waters; and (3) enhanced tropical: tropical forms which are more abundant and/or robust in areas of upwelling.