Plant Microfossils from the Hawks Crag Breccia, south-west Nelson, New Zealand

Abstract

Abstract Thirty miospore species from a sandstone sample of the Hawks Crag Breccia at Fox River are listed and some are described. Twenty-four species are recorded from this formation for the first time; of these, three are new. The assemblage is compared with Upper Jurassic and Lower Cretaceous microfloras from Australia and New Zealand and with other microfloras from the Hawks Crag Breccia and Ohika Beds. Microfloral composition of Tithonian assemblages from the Puaroan B and overlying Huriwai Formation of south-west Auckland is summarised. The Hawks Crag assemblage is concluded to be either Albian or Heterian-Ohauan in age (Lower to Middle Kimmeridgian). The apparent conflict of the Jurassic age-determination and the mid-Cretaceous age, indicated by radiometric methods in underlying crystalline rocks, is discussed. If the Jurassic age is correct, phytogeographic considerations suggest that certain floral elements present in New Zealand in the late Jurassic migrated slowly to the Australian continent, w...