Coiling excursions in Globorotalia miotumida; high resolution bioevents at the middle-upper Miocene boundary in southern temperate water masses?

Author(s): Scott, G. H.
Author Affiliation(s): Primary:
Institute of Geological & Nuclear Sciences, Hydrocarbons & Sedimentary Basins Group, Lower Hutt, New Zealand
Volume Title: Institute of Geological & Nuclear Sciences Contribution
Source: Institute of Geological & Nuclear Sciences Contribution, Vol.443, p.299-308. Publisher: Institute of Geological & Nuclear Sciences, Lower Hutt, New Zealand
Note: In English. Reprinted from Journal of Foraminiferal Research, Vol. 25, No. 4. 25 refs.; illus.
Summary: Coiling directions in Globorotalia miotumida (planktic foraminifera) are reported from five sequences in New Zealand and the southwest Pacific Ocean between 31°S and 40°S. All show a well-defined zone (here termed the Kaiti coiling zone) near the base of the upper Miocene in which the long-term succession of sinistrally dominated populations is replaced by one or more intervals where dextrally coiled shells are in the majority. The zone is widespread in the region and occurs in neritic through oceanic sediments. Changes in dominant coiling direction are abrupt and local stratigraphic resolution is potentially high, (possibly 15 ky). The last occurrence of Paragloborotalia mayeri was near the base of the zone, which at DSDP Site 290B lies in the lower part of oxygen isotope Zone Mi6 and may have occurred during cool climatic conditions. However, comparison of coiling signatures with δ18O data and relative abundances of other planktic foraminifera does not identify any simple, consistent environmental relationship. It is suggested that coiling direction has some features of an evolutionary character.
Year of Publication: 1995
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 10 Paleontology, Invertebrate; 12 Stratigraphy, Historical Geology and Paleoecology; Australasia; Biologic evolution; Biostratigraphy; Biozones; Cenozoic; Coiling; DSDP Site 284; DSDP Site 590; DSDP Site 593; Deep Sea Drilling Project; Foraminifera; Globigerinacea; Globorotalia; Globorotaliidae; IPOD; Invertebrata; Isotope ratios; Isotopes; Kaiti Beach; Karamu Stream; Leg 29; Leg 90; Microfossils; Miocene; Morphology; Neogene; New Zealand; North Island; O-18/O-16; Oxygen; Pacific Ocean; Paleoenvironment; Planktonic taxa; Protista; Rotaliina; Shells; Stable isotopes; Taranaki New Zealand; Tertiary
Coordinates: S385000 S383500 E1782000 E1775000
Record ID: 1997068151
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by Institute of Geological and Nuclear Sciences Limited (GNS Science), Lower Hutt, New Zealand