Globorotalia(planktic Foraminiferida) in the Late Pliocene and Early Pleistocene of New Zealand

Abstract

In the East Coast Basin, Globorotalia crassaformis coils predominantly sinistrally in the Opoitian and Waipipian Stages (Early to Late Pliocene), dextrally in the Mangapanian and lower Nukumaruan (Late Pliocene and Early Pleistocene), and sinistrally in the upper Nukumaruan (Pleistocene). Globorotalia crassula appears as an immigrant, approximately at the base of the Nukumaruan, at about the same level as the earliest appearance of the subantarctic mollusc Chlamys delicatula, and overlaps with the range of dextrally coiling G. crassaformis in the lower Nukumaruan. Globorotalia tosaensis and small morpho types of G. truncatulinoides appear in the Mangapanian, becoming replaced gradually by more typical G. truncatulinoides in the Nukumaruan. One new species, Globorotalia crassaconica (Opoitian-Waipipian), and 1 new subspecies, G. puncticulata puncticuloides (Mangapanian-Nukumaruan), are described. DSDP Site 284, 400 km west of New Zealand, has a similar sequence of planktic foraminifera and the {iGloborotalia crassula} to dextral {iG. crassaformis} overlap-zone is between 50 and 60 m subbottom, in an interval with a marked enrichment of 18₀. In the paleomagnetically zoned Mangaopari Stream section, G. crassula and Chlamys delicatula first appear between the Gauss normal polarity zone and the Olduvai normal polarity subzone.