Pleistocene glaciomarine sediments of the Kisbee Formation, Wilson River, southwest Fiordland, and some tectonic and paleoclimatic implications

Abstract

Fossiliferous sediments of Kisbee Formation (new name) preserved in the Wilson River east of Puysegur Point, southwest Fiordland, are interpreted as filling a submarine canyon that was incised 160 m into Ordovician metasedi‐ments. The formation reflects deposition in quiet, deep cold water beneath floating ice, transitional into shallower water adjacent to an ice‐marginal environment. The macrofauna and nannoflora indicate deposition within Castlecliffian time, somewhere between 0.5 and 1.2 Ma, at depths estimated to range between 50–150 and >200 m. A sequence of marine terraces adjacent to the Wilson River is correlated to global sea‐level records, constraining the local uplift rate to 0.57 ± 0.04 mm/yr and the minimum age for Kisbee Formation to 0.69 Ma. If, as seems likely, the Matuyama‐Brunhes paleo‐magnetic transition lies within the mapped section, Kisbee Formation is older than 0.78 Ma at the the base, and Limopsis lived in >200 m of water.

Keywords:

• Southwest Fiordland
• Kisbee Formation
• glaciomarine
• marine terraces
• Zygochlamys
• nannofossils
• Castlecliffian
• Pleistocene
• Quaternary uplift
• paleoenvironment
• new stratigraphic name