Proterozoic microfossils from the Amelia Dolomite, McArthur Basin, Northern Territory

Abstract

Nineteen species and eight genera of microfossils in the Amelia Dolomite microflora (ca 1.5 × 10⁹ years old) are described and named. Of these, two genera (Ameliaphycus, Myxomorpha) and eleven species (Gunflintia oehlerae, Huroniospora ornata, Sphaerophycus reticulatum, S. tetragonalis, Myxococcoides reniformis, M. minutus, M. kingii, M. konzalovae, Palaeoanacystis plumbii, Ameliaphycus croxfordii, Myxomorpha janecekii) are new. Most of the micro-fossils are interpreted as being the remains of blue-green algae and the assemblage is compared with older and younger microfloras, as well as the Paradise Creek and Bungle Bungle Dolomite assemblages which are of similar age. In addition, mucilaginous moulds of both coccoid and filamentous micro-organisms are described, and some indirect evidence for the activity of sulphate reducing bacteria is presented.