Fauna and biostratigraphy of the Cambrian (Series 2, Stage 4; Ordian) Tempe Formation (Pertaoorrta Group), Amadeus Basin, Northern Territory PATRICK M. SMITH, GLENN A. BROCK and JOHN R. PATERSON SMITH, P.M., BROCK, G.A. & PATERSON, J.R., 2015. Fauna and biostratigraphy of the Cambrian (Series 2, Stage 4; Ordian) Tempe Formation (Pertaoorrta Group), Amadeus Basin, Northern Territory. Alcheringa 39, 40–70. ISSN 0311-5518 A new faunal assemblage is reported from the Tempe Formation (Cambrian Series 2, Stage 4; Ordian) retrieved from the Hermannsburg 41 drill- core, Amadeus Basin, central Australia. Two trilobite taxa, including one new species Gunnia fava sp. nov., four brachiopod taxa, including the age-diagnostic Karathele napuru (Kruse), Kostjubella djagoran (Kruse) and Micromitra nerranubawu Kruse, together with a bradoriid, helcionel- lids, hyoliths, echinoderms, chancelloriids, sponges and problematic tubes are described. The fauna has close links to those of the neighbouring Daly, Georgina and Wiso basins and suggests that the Tempe Formation correlates with the Australian Ordian stage (either the Redlichia forresti or Xystridura negrina assemblage zones). The Giles Creek Dolostone in the eastern Amadeus Basin, previously regarded as coeval with the Tempe Formation, has recently been reported to be of early Templetonian age in its type section. The described taxa from the Tempe Formation confirm that these two sedimentary units are not contemporaneous and that regional stratigraphic schemes should be amended. P.M. Smith [patrick-mark.smith@students.mq.edu.au] and G.A. Brock [glenn.brock@mq.edu.au] Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia. J.R. Paterson [jpater20@une.edu.au] School of Environmental and Rural Science, University of New England, Armidale, New South Wales, 2351, Australia. Received 11.6.2014; revised 10.7.2014; accepted 29.7.2014. Key words: trilobites, brachiopods, shelly fossils, East Gondwana, Australia. CAMBRIAN fossils from the Amadeus Basin (Fig. 1) were first reported by Madigan (1932) over 80 years ago, but no formal systematic descriptions were pub- lished until the late 1960s (Öpik 1968). Scientific descriptions of Cambrian shelly fossils have largely focused on faunas preserved in the Todd River Dolostone (Kruse & West 1980, Kennard 1983, Laurie & Shergold 1985, Laurie 1986), Giles Creek Dolostone (Öpik 1968, 1970a, b, 1975, 1982, Smith et al. 2014) and the Goyder Formation (Öpik 1967, Pojeta et al. 1977), with almost nothing published on other Cambrian units from the basin (see Shergold 1986, Shergold et al. 1991 for an overview). Although the clastic-dominated central part of the basin (Deception Formation, and Cleland, Illara and Petermann sandstones) is unfossilifer- ous, the marine deposits of the Tempe Formation have largely been overlooked. Based on the preliminary reports of Wells et al.(1970) and Shergold (1986), the Tempe Formation and the Giles Creek Dolostone (particularly prevalent in the east of the basin), have lar- gely been assumed to be contemporaneous based on their fossil content (Shergold 1986). The main aim of this investigation is to systematically sample shelly fossils from the Hermannsburg 41 drillcore from the central Amadeus Basin in order to complete the first taxonomic descriptions of the fauna from the Tempe Formation, compile biostratigraphic range data for all fossil taxa and compare the assemblages with those from the Giles Creek Dolostone (Smith 2012, Smith et al. 2014) in order to test the proposed stratigraphic correlation of these units. Geological setting and locality The Amadeus Basin is a large intracratonic depocentre of Neoproterozoic to Carboniferous sedimentary rocks located in central Australia (Fig. 1). The eastern and western boundaries of the basin are buried under youn- ger sedimentary deposits, and the northern and southern limits are structural and/or erosional rather than deposi- tional (Edgoose 2012). The Hermannsburg 41 corehole was drilled by the Bureau of Mineral Resources (now Geoscience Australia) in 1985 with the purpose of investigating the stratigraphy of the Pertaoorrta Group within the Carmichael Sub-basin, in particular around the area of the Gardiner Range, about 200 km west of Alice Springs (Fig. 1). The Pertaoorrta Group within the Carmichael Sub-basin reaches a maximum thickness of 2800 m, although the average thickness is closer to 2100 m (Lindsay & Korsch 1989, 1991). Similar © 2014 Association of Australasian Palaeontologists http://dx.doi.org/10.1080/03115518.2014.951917 Downloaded by [University of New England] at 14:57 03 February 2015