Late Haumurian (Maastrichtian) microfossils from Chatham Islands, New Zealand
Strong, C. P.; Edwards, A. R.; Strong, C. P.; DSIR, New Zealand Geological Survey; Edwards, A. R.; DSIR, New Zealand Geological Survey
Журнал:
New Zealand Journal of Geology and Geophysics
Дата:
1979
Аннотация:
AbstractTwo limestone samples, collected from small outcrops on Chatham and Pitt Islands, contain late Haumurian foraminifera and calcareous nannofossils, and constitute the first record of uppermost Cretaceous strata from Chatham Islands or elsewhere on Chatham Rise.Paleoecologic analysis of microfossil assemblages from the limestones, the underlying Kahuitara Tuff (early( ?) Haumurian) and the overlying Red Bluff Tuff and Flowerpot Limestone (Early Paleogene), indicates that roughly 100 m of submergence during Haumurian time was followed by a similar amount of Early Paleogene shallowing. Comparison of Chatham Island, New Zealand, and worldwide bathymetric trends indicates that Chatham Islands acted as a structurally independent unit. Integration of local bathymetric trends with local stratigraphy suggests that the observed bahymetric changes result from vertical movements associated with cessation, then renewal, of intensive volcanism in Chatham Islands.
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