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An Early Permian brachiopod–gastropod fauna from the Calytrix Formation, Barbwire Terrace, Canning Basin, Western Australia

2015; Taylor & Francis; Volume: 39; Issue: 2 Linguagem: Inglês

10.1080/03115518.2015.965921

1752-0754

Arturo César Taboada, Arthur J. Mory, G.R. Shi, David W. Haig, María Karina Pinilla,

Geological and Geophysical Studies

AbstractTaboada, A.C., Mory, A.J., Shi, G.R., Haig, D.W. & Pinilla, M.K., 12.11.2014. An Early Permian brachiopod–gastropod fauna from the Calytrix Formation, Barbwire Terrace, Canning Basin, Western Australia. Alcheringa 39, xxx–xxx. ISSN 0311-5518A small brachiopod–gastropod fauna from a core close to the base of the Calytrix Formation within the Grant Group includes the brachiopods Altiplecus decipiens (Hosking), Myodelthyrium dickinsi (Thomas), Brachythyrinella narsarhensis (Reed), Neochonetes (Sommeriella) obrieni Archbold, Tivertonia barbwirensis sp. nov. and the gastropod Peruvispira canningensis sp. nov. The fauna has affinities with that of the late Sakmarian‒early Artinskian Nura Nura Member directly overlying the Grant Group in other parts of the basin but, as with all lower Cisuralian (and Pennsylvanian) glacial strata in Western Australia, its precise age remains poorly constrained, especially in terms of correlation to international stages. Although the Calytrix fauna lies within the Pseudoreticulatispora confluens Palynozone, the only real constraint on its age (and that of the associated glacially influenced strata) is from Sakmarian (Sterlitamakian) and stratigraphically younger faunas. A brief review of radiometric ages from correlative strata elsewhere in Gondwana shows that those ages need to be updated. The presence of Asselian strata and the position of the Carboniferous‒Permian boundary remain unclear in Western Australia.Arturo César Taboada [ataboada@unpata.edu.ar], CONICET-Laboratorio de Investigaciones en Evolución y Biodiversidad (LIEB), Facultad de Ciencias Naturales, Sede Esquel, Universidad Nacional de la Patagonia 'San Juan Bosco', Edificio de Aulas, Ruta Nacional 259, km. 16,5, Esquel U9200, Chubut, Argentina; Arthur Mory [arthur.mory@dmp.wa.gov.au], Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Guang R. Shi [grshi@deakin.edu.au], School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; David W. Haig [david.haig@uwa.edu.au], School of Earth and Environment (M004), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; María Karina Pinilla [mkpinilla@fcnym.unlp.edu.ar], División Paleozoología Invertebrados, Museo de Ciencias Naturales de La Plata, Paseo del Bosque s/n, 1900 La Plata, Buenos Aires, Argentina.格兰特群Calytrix组近底部的一个小腕足类-腹足类动物群包括腕足动物Altiplecus decipiens (Hosking)、 Myodelthyrium dickinsi (Thomas)、 Brachythyrinella narsarhensis (Reed),、Neochonetes (Sommeriella) obrieni Archbold、 Tivertonia barbwirensis sp. nov. 以及腹足动物 Peruvispira canningensis sp. nov.。该动物群与盆地其余部分的格兰特群之上覆的Sakmarian晚期-Artinskian早期的Nura Nura 段中的动物群有亲缘关系。但是,与西澳的所有Cisuralian下部(宾夕法尼亚)冰川岩层一样,其确切年龄仍然没有确定,尤其是与国际地层的对比方面。虽然Calytrix动物群位于Pseudoreticulatispora confluens 孢粉带 之内,其唯一的真正的年龄确定因素(以及相关的冰川影响的阶层)是Sakmarian阶(Sterlitamakian)及更年轻地层中的动物群。冈瓦纳其它地区相关地层的放射性年龄简要回顾显示,那些年龄需要更新。澳大利亚西部是否有Asselian阶地层的存在以及石炭 - 二叠系界线的位置尚不清楚。Key words: SakmarianBrachiopodaGastropodaEast Gondwana interior rift. AcknowledgementsWe thank John Backhouse (University of Western Australia), and the reviewers, Hamish Campbell, Bruce Runnegar and Masatoshi Sone, as well as the editor, Stephen McLoughlin, for their useful comments on the manuscript. PIP 237-CONICET and PICT 1589-FONCYT provided financial support, and the Centro de Investigaciones Esquel de Montaña y Estepa Patagónicas (CIEMEP) supplied laboratory facilities for ACT. Thanks to Ms Laura Reiner for preparing and photographing the gastropods. AJM publishes with the permission of the Director, Geological Survey of Western Australia.