A mid-Givetian miospore age for the onset of reef development on the Lennard Shelf, Canning Basin, Western Australia

Abstract

Miospores from boreholes through the earliest sediments associated with the onset of the formation of reef complexes on the Lennard Shelf of northern Western Australia include representatives of the Geminospora lemurata-Cymbosporites magnificus and Contagisporites optivus-Cristalisporites triangulatus Assemblage Zones. The palynofloral evidence indicates that deposition of the reef sequence began in the mid-Givetian, rather than latest Givetian as previously thought. Palynomorphs become sparser with increase in carbonate content and consequently middle Frasnian to Famennian palynomorph zones cannot be distinguished in the reef complexes.