Cretaceous—tertiary boundary, mid-waipara river section, north canterbury, new zealand

Abstract

The Cretaceous-Tertiary boundary in the mid-Waipara River Stratigraphic succession is interpreted to coincide with the base of the 4 m thick, weathered glauconitic sandstone forming the uppermost unit of the Laidmore Formation. The boundary is herein defined to within 40 cm on paleontological evidence; the base of the glauconitic sandstone lies at the middle of this interval.Samples 20 cm below the adopted boundary contain diagnostic late Haumurian (Maastrichtian) foraminifera, including Gaudryina healyi Finlay and Hedbergella monmouthensis (Olsson), and nannofossils, including Nephrolithus frequens Górka. A sample from 20 cm above the adopted boundary contains the diagnostic Lower Teurian (Paleocene) planktic foraminifer, Globigerina pauciloculata Jenkins, and a species tentatively identified as Globigerina eugubina Luterbacher and Premoli Silva, an earliest Paleocene index. The mid-Waipara sequence appears to be by far the most complete Lower Teurian succession yet identified in New Zealand, as approximately the lowest 40 m of Teurian strata there apparently are represented by unconformities in other New Zealand Cretaceous-Tertiary boundary sequences. © 1984 Taylor & Francis Group, LLC.