Dinoflagellate biostratigraphy of the middle Coniacian - lower Campanian (Upper Cretaceous) in south Marlborough, New Zealand

The dinoflagellate distribution in two Teratan-lower Haumurian (Coniacian-C ampanian) sections at Ben More Stream and Kekerengu River (south Marlboroug h, New Zealand) is documented and discussed, and a new zonation scheme prop osed. The Conosphaeridium striatoconum Zone of Wilson (1984) and the Odonto chitina porifera Zone of Wilson (1984) are proposed as new Superzones. The C. striatoconum Superzone is subdivided into three new zones: Chlamydophore lla ambigua Interval Zone, Cymososphaeridium benmorense Interval Zone and C onosphaeridium abbreviatum Interval Zone. Four Australian dinoflagellate zo nes are recognized in the sections: Odontochitina porifera Interval Zone of Helby et al. (1987), Isabelidinium cretaceum Zone of Evans (1971), Nelsoni ella aceras Zone of Evans (1971) and Satyrodinium haumuriense Zone of Marsh all (1990). A correlation of the two sections with international stages bas ed on key dinoflagellates and supported by previous work on inoceramid biva lves dates the sections as middle Coniacian to early Campanian. The Teratan -Piripauan stage boundary can be placed in the uppermost Coniacian and the Piripauan-Haumurian stage boundary in the upper Santonian. Six new dinoflag ellate species are present in the sections: Batiacasphaera kekerengensis n. sp., Batiacasphaera rugulata n, sp., Cymososphaeridium benmorense n. sp., Eucladinium kaikourense n. sp., Glaphyrocysta marlboroughensis n. sp. and K leithriasphaeridium secatum n. sp.