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| | | | Geological Survey of Western Australia |
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| | | | DE Kelsey | | | | | Event type | tectonic: orogeny | Parent event | _Top of Event list | Child events | | Tectonic units affected | | Tectonic setting | orogen: undivided | Metamorphic facies | | Metamorphic/tectonic features | –– |
| | | Summary | The Parnngurr Orogeny is currently defined on the basis of one metamorphic study, Anderson (2015), that provides monazite and zircon U-Pb geochronology. Magmatism of the Camel Suite occurred over at least part of this time frame. Metamorphism was of moderate apparent thermal gradient (high-pressure Barrovian), suggestive of crustal thickening. The tectonic setting remains uncertain, but the timeframe overlaps with that of the Mount West Orogeny (Musgrave Province) and Stage I Albany–Fraser Orogeny. | | | Distribution | In terms of metamorphic age data it is currently limited to the Talbot and Connaughton Terranes of the Rudall Province. However, magmatism of the Camel Suite is additionally known from the Tabletop Terrane, which likely implies the Parnngurr Orogeny affected all three parts of the Rudall Province. | | | Description | The name Parnngurr is derived from the name of an indigenous community located in the central Rudall Province, ~1.5 km north of the southern boundary of the Karlamilyi National Park, on the RUDALL 1:250 000 map sheet and CONNAUGHTON 1:100 000 map sheet. | | | | | | Geochronology | | | Parnngurr Orogeny | Maximum age | Minimum age | Age (Ma) | 1377 ± 26 | 1275 ± 11 | Age | Mesoproterozoic | Mesoproterozoic | Age data type | Isotopic | | References | | | Anderson (2015) | Anderson (2019) |
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| The age span of the Parnngurr Orogeny is currently defined by a single study, Anderson (2015), of which the specific PhD chapter on the Rudall Province was re-published as a GSWA Record in 2019 (as Anderson, 2019). The maximum age is zircon U–Pb data from sample 113019, a garnet-clinopyroxene mafic amphibolite (foliated, un-migmatised) from within the kyanite zone of the Connaughton Terrane. The sample contains only a small number of low-U zircons, hence the reason for the large uncertainty on the age. The minimum age is defined by monazite U-Pb data from sample 103603D, a sericitised kyanite-plagioclase-quartz-rutile-ilmenite-bearing metapelite from the Talbot Terrane.
Other studies have provided magmatic ages for the Camel Suite, which was intruded over a narrower portion of this time interval (Nelson, 1995 [sample 104938], 1996 [sample 118914]; Bagas, 2004, Precambrian Research; Maidment, 2017, GSWA Report 161; Payne et al., 2021, Precambrian Research), but these studies have not modified the original age span defined by Anderson (2015), nor do they directly date metamorphism. | | | Tectonic Setting | Tectonic setting is uncertain at this stage. Metamorphic age data from Anderson (2015) establishes that metamorphism is occurring at this time. Thermal gradients of metamorphism are ~60-80 °C/kbar (high-pressure Barrovian thermal conditions; e.g. Brown, 2006, Geology) and these are suggestive of a setting involving crustal thickening. It possibly reflects the amalgamation of the North and West Australian Cratons. The timeline overlaps with Stage I of the Albany-Fraser Orogen and the Mount West Orogeny (Musgrave Province) and suggests a linked history. There are felsic and mafic magmatic rocks in the Rudall Province from this timeframe (Camel Suite). The felsic rocks are mostly high silica potassic leucogranites derived mostly from reworking of existing crust. Gabbroic rocks attest to mantle melting at this time. Payne et al. (2021, Precambrian Research) propose an arc (upper plate) setting for the Parnngurr Orogeny, but direct evidence of an arc is lacking. It is also not clear that the Parnngurr Orogeny represents a plate-margin event - it may instead be intraplate. | | | | References | Anderson, J 2015, Metamorphic and isotopic characterisation of Proterozoic belts at the margins of the North and West Australian Cratons: University of Adelaide, Adelaide, South Australia, PhD thesis (unpublished), 149p. | Anderson, J 2019, Metamorphic and isotopic characterisation of Proterozoic belts at the margins of the North and West Australian Cratons: Mesoproterozoic metamorphism in the Rudall Province: revising the timeline of the Yapungku Orogeny and implications for cratonic Australia assembly: Geological Survey of Western Australia, Record 2019/8, 47p. | Bagas, L 2004, Proterozoic evolution and tectonic setting of the northwest Paterson Orogen, Western Australia: Precambrian Research, v. 128, p. 475–496, doi:10.1016/j.precamres.2003.09.011. | Maidment, DW 2017, Geochronology from the Rudall Province, Western Australia: Implications for the amalgamation of the West and North Australian Cratons: Geological Survey of Western Australia, Report 161. View Reference | Nelson, DR 1995, 104938.1: pegmatite, Coondegoon; Geochronology Record 35: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Nelson, DR 1996, 118914.1: foliated granite, north of Harbutt Range; Geochronology Record 485: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Payne, JL, Morrissey, LJ, Tucker, NM, Roche, LK, Szpunar, MA and Neroni, R 2021, Granites and gabbros at the dawn of a coherent Australian continent: Precambrian Research, v. 359, article no. 106189, doi:10.1016/j.precamres.2021.106189. |
| | | | Recommended reference for this publication | Kelsey, DE 2021, Parnngurr Orogeny (PA): Geological Survey of Western Australia, WA Geology Online, Explanatory Notes extract, viewed 05 August 2025. <www.dmp.wa.gov.au/ens> |
| | | This page was last modified on 18 June 2021. | | | | | Grid references in this publication refer to the Geocentric Datum of Australia 1994 (GDA94). Locations mentioned in the text are referenced using Map Grid Australia (MGA) coordinates, Zones 49 to 52. All locations are quoted to at least the nearest 100 m. Capitalized names in text refer to standard 1:100 000 map sheets, unless otherwise indicated. WAROX is GSWA’s field observation and sample database. WAROX site IDs have the format ‘ABCXXXnnnnnnSS’, where ABC = geologist username, XXX = project or map code, nnnnnn = 6 digit site number, and SS = optional alphabetic suffix (maximum 2 characters). All isotopic dates are based on U–Pb analysis of zircon and quoted with 95% uncertainties, unless stated otherwise. U–Pb measurements of GSWA samples were conducted using a sensitive high-resolution ion microprobe (SHRIMP) in the John de Laeter Centre at Curtin University, Perth, Western Australia. Digital data related to WA Geology Online, including geochronology and digital geology, are available online at the Department’s Data and Software Centre and may be viewed in map context at GeoVIEW.WA. | | | Further details of geological publications and maps produced by the Geological Survey of Western Australia are available from: Information Centre Department of Mines, Industry Regulation and Safety 100 Plain Street EAST PERTH, WA 6004 Telephone: +61 8 9222 3459 Facsimile: +61 8 9222 3444 |
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