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| | | | Geological Survey of Western Australia |
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| | | | AH Hickman | | | | | Event type | deformation: undivided | Parent event | | Child events | | Tectonic units affected | | Tectonic setting | orogen: undivided | Metamorphic facies | | Metamorphic/tectonic features | –– |
| | | Summary | Doming, sagduction, granitic intrusion, and metamorphism during the Warrawoona Event followed deposition of the 15 km-thick Warrawoona Group between c. 3530 and 3427 Ma. Although this was not the first doming event in the East Pilbara Terrane it was the most widespread and it marked the end of mantle plume activity for about 75 Ma. Major uplift took place in the granitic cores of the Carlindi, Muccan, Warrawagine, Shaw, Tambourah, North Pole and Mount Edgar Domes, and subsequent deep erosion of these structures led to deposition of the c. 3426–3350 Ma Strelley Pool Formation across angular unconformities. Almost all the granitic gneisses of the East Pilbara Terrane were metamorphosed during the Warrawoona Event. Less deformation in the southeastern part of the East Pilbara Terrane resulted in the Strelley Pool Formation overlying the Warrawoona Group disconformably.
The Warrawoona Event was preceded by eruption of the Panorama Formation, which took place in several separate volcanic complexes. Some workers have suggested that these centres of felsic volcanism and related underlying granitic intrusions were located in areas now occupied by the cores of the granite–greenstone domes. This would be consistent with the interpretation that dome location was influenced by lateral variations in the composition of the crust, more felsic crust rising preferentially to denser crust during partial convective overturn. The main trigger for doming was undoubtedly inverted density stratification resulting from the 15 km-thick Warrawoona Group, composed of relatively dense mafic rocks, resting on less dense, more felsic crust. However, other contributing factors are interpreted to have included increased crustal temperatures due to mantle plume activity, radiogenic decay and thermal insulation by the thick volcanic cover of the Warrawoona Group. | | | Distribution | Effects of the Warrawoona Event are restricted to the 40 000 km² outcrop area of the East Pilbara Terrane. Within this terrane, major deformation took place in the Carlindi, Muccan, Warrawagine, Shaw, Tambourah, North Pole and Mount Edgar Domes. Results of the event are less evident in the southeastern part of the East Pilbara Terrane where most of the domes are exposed at higher structural levels (closer to the tops of the granitic cores). | | | Description | The Warrawoona Event took place between c. 3430 and 3410 Ma, following eruption of the Panorama Formation. This event had limited impact on those areas of the southeastern East Pilbara Terrane now occupied by the Corunna Downs, McPhee and Yilgalong Domes. However, deformation, metamorphism and melting happened in the Muccan Dome (Wiemer et al., 2016), Shaw Dome (Van Kranendonk, 1997, 2000; Pawley et al., 2004; Van Kranendonk et al., 2004, 2006), Warrawagine Dome (Williams, 2003) and Mount Edgar Dome (Kloppenburg, 2003). In the Mount Edgar Dome, the Beaton Well Zone (Kloppenburg, 2003; Gardiner et al., 2018) was formed at c. 3420 Ma and is exposed as a synformal belt in the 3448–3416 Ma Fig Tree Gneiss. The age of the Beaton Well structure is indicated by its abrupt truncation by the c. 3320 Ma Joorina Granodiorite in the northeast and by the c. 3315 Ma Limestone Shear Zone to the southwest. The Beaton Well Zone is interpreted to separate two early domes within the Mount Edgar Dome (Hickman, 1975, 1983). The angular unconformity at the base of the 3426–3350 Ma Strelley Pool Formation in the Carlindi Dome (Buick et al., 1995; Green et al., 2000; Van Kranendonk, 2000; Van Kranendonk et al., 2002, 2006; Hickman, 2008; Wacey et al., 2010), North Pole Dome (Van Kranendonk, 2000; Allwood et al., 2007; Hickman, 2008) and Muccan Dome (Van Kranendonk, 2010; Wiemer et al., 2016) was the result of major uplift and erosion prior to c. 3426 Ma.
Much of the tonalite–trondhjemite–granodiorite (TTG) of the 3451–3416 Ma Tambina Supersuite was intruded during the event, and is likely to have been partly derived by partial melting of sagducted mafic rocks of the Warrawoona Group. Metamorphism of the Tambina Supersuite and adjacent greenstones to form gneisses and schists is interpreted to have happened at mid-crustal levels. Vertical uplift in the domes was locally up to 25 km (Délor et al., 1991; Collins and Van Kranendonk, 1999; François et al., 2014), although some uplift is likely to have taken place during the 3325–3290 Ma Emu Pool Event. Widespread leucogranite in the Tambina Supersuite of the Shaw Dome represents melt derived from the Callina Supersuite (Van Kranendonk, 2000; Pawley et al., 2004; Van Kranendonk et al., 2004). | | | | | | Geochronology | | | Warrawoona Event | Maximum age | Minimum age | Age (Ma) | 3430 | 3410 | Age | Paleoarchean | Paleoarchean | Age data type | Inferred | | References | | |
| The maximum age of the Warrawoona Event approximates to the minimum age of the Panorama Formation, because the location of domes formed during the event that is thought to have coincided with the location of felsic volcanic complexes of that formation (Barley, 1981; DiMarco and Lowe, 1989a,b; Van Kranendonk, 2000). Thick units of felsic volcanic rock and underlying subvolcanic intrusions would have defined areas of low density most susceptible to doming. Most volcanic activity of the Panorama Formation took place at c. 3430 Ma, suggesting the doming event happened after that. It should be noted that an earlier event of deformation and erosion took place during the eruption of the Panorama formation at c. 3445 Ma (Hickman, 2021), but this is not considered to be part of the Warrawoona Event.
The Warrawoona Event included emplacement of several intrusions of the Tambina Supersite, the youngest intrusion which was dated at 3410 ± 7 Ma (GSWA 142870, Nelson, 1999). Detrital zircons in the 3426–3350 Ma Strelley Pool Formation do not have crystallization ages younger than c. 3410 Ma. Accordingly, it is inferred that the minimum age of the Warrawoona Event is c. 3410 Ma. Evidence in support for this interpretation includes the observation that no intrusions of the Tambina Supersuite intrude the Strelley Pool Formation, and that the Strelley Pool Formation is not deformed by any of the deformation assigned to the Warrawoona Event. | | | Tectonic Setting | By c. 3430 Ma, the crust beneath the mainly mafic and ultramafic succession of the Warrawoona Group was predominantly felsic. The resulting inverted density stratification led to doming and sagduction of the crust. Increased temperatures and melting in the mantle and mid- to lower crust due to mantle plume activity, radiogenic decay and thermal insulation by the overlying, 15 km-thick cover of the Warrawoona Group are also likely to have contributed the doming and sagduction.
Based on the regional distribution of the Tambina Suite within the East Pilbara Terrane, from the Warrawagine Dome in the northeast to the western part of the Yule Dome in the west, the mantle plume that led to the Warrawoona Event is interpreted to have impacted the entire area of the East Pilbara Terrane. Based on the interpretation that the Pilbara Craton was linked to the east Kaapvaal Craton as part of Vaalbara in the Archean (Zegers et al., 1998; Hickman, 2016, 2021), dating of several c. 3445 Ma TTG intrusions in the Kaapvaal Craton (Lowe and Byerly, 1999) suggests that effects of the plume might have extended well outside the area of the East Pilbara Terrane. | | | | References | Allwood, AC, Burch, I and Walter, MR 2007, Stratigraphy and facies of the 3.43 Ga Strelley Pool Chert in the southwestern North Pole dome, Pilbara Craton, Western Australia: Geological Survey of Western Australia, Record 2007/11, 22p. View Reference | Barley, ME 1981, Relations between volcanic rocks in the Warrawoona Group: continuous or cyclic evolution?: Geological Society of Australia, Special Publication, v. 7, p. 263–273. | Buick, R, Thornett, J, McNaughton, N, Smith, JB, Barley, ME and Savage, MD 1995, Record of emergent continental crust ~3.5 billion years ago in the Pilbara Craton of Australia: Nature, v. 375, p. 574–577. | Collins, WJ and Van Kranendonk, MJ 1999, Model for the development of kyanite during partial convective overturn of Archaean granite–greenstone terranes: the Pilbara Craton, Australia: Journal of Metamorphic Geology, v. 17, p. 145–156, doi:10.1046/j.1525-1314.1999.00187.x. | Délor, C, Burg, JP and Clarke, G 1991, Relations diapirisme-metamorphisme dans la Province du Pilbara (Australie occidentale): implications pour les régimes thermiques et tectoniques à la Archéen: Compte Rendu Academie de Sciences Paris, v. 312, no. 3, p. 257–263. | DiMarco, MJ and Lowe, DR 1989, Stratigraphy and sedimentology of an Early Archean felsic volcanic sequence, eastern Pilbara block, Western Australia, with special reference to the Duffer Formation and implications for crustal evolution: Precambrian Research, v. 44, p. 147–169. | DiMarco, MJ and Lowe, DR 1989, Shallow-water volcaniclastic deposition in the Early Archean Panorama Formation, Warrawoona Group, eastern Pilbara Block, Western Australia: Sedimentary Geology, v. 64, no. 1–2, p. 43–63. | François, C, Philippot, P, Rey, PF and Rubatto, D 2014, Burial and exhumation during Archean sagduction in the east Pilbara granite–greenstone terrane: Earth and Planetary Science Letters, v. 396, p. 235–251. | Gardiner, NJ, Hickman, AH, Kirkland, CL, Lu, Y, Johnson, TE and Wingate, MTD 2018, New Hf isotope insights into the Paleoarchean magmatic evolution of the Mount Edgar Dome, Pilbara Craton: Implications for early Earth and crust formation processes: Geological Survey of Western Australia, Report 181, 41p. View Reference | Green, MG, Sylvester, PJ and Buick, R 2000, Growth and recycling of early Archaean continental crust: Geochemical evidence from the Coonterunah and Warrawoona Groups, Pilbara Craton, Australia: Tectonophysics, v. 322, no. 1, p. 69–88. | Hickman, AH 1975, Precambrian structural geology of part of the Pilbara Region, in Annual report for the year 1974: Geological Survey of Western Australia, p. 68–73. View Reference | Hickman, AH 1983, Geology of the Pilbara Block and its environs: Geological Survey of Western Australia, Bulletin 127, 268p. View Reference | Hickman, AH 2008, Regional review of the 3426–3350 Ma Strelley Pool Formation, Pilbara Craton, Western Australia: Geological Survey of Western Australia, Record 2008/15, 27p. View Reference | Hickman, AH 2016, Interpreted bedrock geology of the east Pilbara Craton (1:250 000 scale), in East Pilbara Craton: a record of one billion years in the growth of Archean continental crust by AH Hickman: Geological Survey of Western Australia, Report 143, Plate 1A. View Reference | Hickman, AH 2021, East Pilbara Craton: a record of one billion years in the growth of Archean continental crust: Geological Survey of Western Australia, Report 143, 187p. View Reference | Kloppenburg, A 2003, Structural evolution of the Marble Bar Domain, Pilbara granite-greenstone terrain, Australia: the role of Archaean mid-crustal detachments: Utrecht University, Utrecht, the Netherlands, PhD thesis (unpublished), 256p. | Lowe, DR and Byerly, GR 1999, Stratigraphy of the west-central part of the Barberton Greenstone Belt, South Africa, in Geologic evolution of the Barberton Greenstone Belt, South Africa edited by Lowe, DR and Byerly, GR: Geological Society of America, Special Papers 329, p. 1–36. | Nelson, DR 1999, 142870.1: banded biotite tonalite gneiss, 6 Mile Well; Geochronology Record 345: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Pawley, MJ, Van Kranendonk, MJ and Collins, WJ 2004, Interplay between deformation and magmatism during doming of the Archaean Shaw granitoid complex, Pilbara craton, Western Australia: Precambrian Research, v. 131, no. 3, p. 213–230. | Van Kranendonk, MJ 1997, Results of field mapping, 1994–1996, in the North Shaw and Tambourah 1:100 000 sheet areas, eastern Pilbara Craton, northwestern Australia: Australian Geological Survey Organisation (Geoscience Australia), Record 1997/23, 44p. | Van Kranendonk, MJ 2000, Geology of the North Shaw 1:100 000 sheet: Geological Survey of Western Australia, 1:100 000 Geological Series Explanatory Notes, 86p. View Reference | Van Kranendonk, MJ 2010, Geology of the Coongan 1:100 000 sheet: Geological Survey of Western Australia, 1:100 000 Geological Series Explanatory Notes, 67p. View Reference | Van Kranendonk, MJ, Collins, WJ, Hickman, AH and Pawley, MJ 2004, Critical tests of vertical vs horizontal tectonic models for the Archean East Pilbara granite–greenstone terrane, Pilbara Craton, Western Australia: Precambrian Research, v. 131, no. 3, p. 173–211. | Van Kranendonk, MJ, Hickman, AH, Smithies, RH, Nelson, DN and Pike, G 2002, Geology and tectonic evolution of the Archaean North Pilbara terrain, Pilbara Craton, Western Australia: Economic Geology, v. 97, p. 695–732, doi:10.2113/gsecongeo.97.4.695. | Van Kranendonk, MJ, Hickman, AH, Smithies, RH, Williams, IR, Bagas, L and Farrell, TR 2006, Revised lithostratigraphy of Archean supracrustal and intrusive rocks in the northern Pilbara Craton, Western Australia: Geological Survey of Western Australia, Record 2006/15, 57p. View Reference | Wacey, D, McLoughlin, N, Stoakes, CA, Kilburn, MR, Green, OR and Brasier, MD 2010, The 3426–3350 Ma Strelley Pool Formation in the East Strelley greenstone belt — a field and petrographic guide: Geological Survey of Western Australia, Record 2010/10, 64p. View Reference | Wiemer, D, Schrank, CE, Murphy, DT and Hickman, AH 2016, Lithostratigraphy and structure of the early Archaean Doolena Gap greenstone belt, East Pilbara Terrane, Western Australia: Precambrian Research, v. 282, p. 121–138. | Williams, IR 2003, Yarrie, Western Australia (3rd): Geological Survey of Western Australia, 1:250 000 Geological Series Explanatory Notes, 84p. View Reference | Zegers, TE, de Wit, MJ, Dann, J and White, SH 1998, Vaalbara, Earth's oldest assembled continent? A combined structural, geochronological, and palaeomagnetic test: Terra Nova, v. 10, p. 250–259. |
| | | | Recommended reference for this publication | Hickman, AH 2024, Warrawoona Event (PCW): 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 05 March 2024. | | | | | 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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