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| | | | Geological Survey of Western Australia |
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| | | | SP Johnson, S Sheppard, and SA Occhipinti | | | | | Event type | tectonic: collisional orogeny | Parent event | | Child events | | Tectonic units affected | | Tectonic setting | orogen: collisional orogen | Metamorphic facies | | amphibolite: undivided | granulite: cordierite - K-feldspar |
| Metamorphic/tectonic features | –– |
| | | Summary | The Glenburgh Orogeny (2005–1950 Ma) is considered to be roughly equivalent to the combined age range of the Dalgaringa Supersuite and the syn-tectonic part of the Bertibubba Supersuite. The orogeny is interpreted to record the tectonomagmatic evolution of an Andean-type arc along the southern margin of the Glenburgh Terrane and its subsequent collision with the Yilgarn Craton. Two discrete tectonometamorphic episodes are recognized within this orogeny (D1g/M1g and D2g/M2g), both of which have been dated directly from the growth of new metamorphic zircon and monazite. D1g/M1g is dated at 2005–1985 Ma and is interpreted to record the construction of the continental margin arc in the middle crust, whereas D2g/M2g is dated at 1965–1950 Ma, and is interpreted to record the terminal closure of the oceanic tract with collision between a previously combined Pilbara Craton – Glenburgh Terrane and the Yilgarn Craton. | | | Distribution | The effects of the Glenburgh Orogeny are recognized across the southern part of the Gascoyne Province, and in the adjacent Errabiddy Shear Zone. In detail, the D1g/M1g event is recorded only in gneissic granites of the Dalgaringa Supersuite in the Paradise Zone, whereas the D2g/M2g event is recorded across the region from the Errabiddy Shear zone to the Mooloo Zone. In the Bryah and Padbury Basins, originally flat-lying D1 structures interpreted to reflect thrusting were considered by Pirajno et al. (2000) to have formed during the Glenburgh Orogeny. | | | Description | The Glenburgh Orogeny comprises two discrete tectonometamorphic episodes (D1g and D2g), both of which have been dated directly from the growth of new metamorphic zircon and monazite.
D1g is restricted entirely to the Paradise Zone, where it is represented by the pervasive development of gneissic fabrics within meta-igneous rocks of the Dalgaringa Supersuite, and within strips of pelitic diatexite and mafic granulite that are intercalated with the gneissic granites. Associated M1g peak metamorphic assemblages record metamorphism mainly in the middle amphibolite facies, but pelitic diatexites and mafic granulites in the central part of the Paradise Zone indicate peak conditions, at least locally, in the granulite facies. The presence of hercynitic-spinel–corundum–almandine-garnet in pelitic diatexites is interpreted by Schulters and Bohlen (1988) to indicate moderate- to high-pressure and temperature conditions, in the range ~7–10 kbar and 800–1000°C. Metamorphism and deformation were contemporaneous with arc magmatism between 2005 Ma and 1985 Ma, and suggest that D1g was associated with the construction of the Dalgaringa Arc in the middle crust (Johnson et al., 2010, 2011).
The D2g event is pervasively recorded in all lithologies from the Errabiddy Shear Zone through to the Mooloo Zone in the southern part of the Gascoyne Province. The widespread production of subhorizontal gneissic fabrics, folds, and foliations indicate the predominance of large horizontal shortening components during D2g deformation. M2g metamorphism was contemporaneous with D2g and was responsible for the widespread migmatization of pelitic and semi-pelitic lithologies of the Camel Hills Metamorphics and Moogie Metamorphics. However, the wholesale destruction and retrogression of these peak metamorphic assemblages during subsequent lower grade metamorphism preclude the precise determination of peak metamorphic conditions across the region. The presence of garnet and sillimanite porphyroblasts within pelitic diatexite lithologies indicates metamorphic conditions peaked in the upper amphibolite to lower granulite facies, with pressures and temperatures at about 5–9 kbar and >650°C (e.g. Rigby, 2009). The widespread and pervasive nature of D2g within lithologies interpreted to have been on different sides of the Dalgaringa Arc and subducting oceanic tract (i.e., on the Pilbara Craton – Glenburgh Terrane or Yilgarn Craton sides), combined with the large horizontal shortening components and peak metamorphic grades associated with M2g, are interpreted to record the collision between a previously assembled Pilbara Craton – Glenburgh Terrane with the Yilgarn Craton along the Errabiddy Shear Zone. Intrusion of the granitic Bertibubba Supersuite throughout the southern Gascoyne Province is coeval with D2g, and is interpreted as a series of syntectonic intrusions that stitch the two cratons (Occhipinti et al., 2004). | | | | | | Geochronology | | | Glenburgh Orogeny | Maximum age | Minimum age | Age (Ma) | 2002 ± 3 | 1947 ± 11 | Age | Paleoproterozoic | Paleoproterozoic | Age data type | Isotopic | | References | | |
| The Glenburgh Orogeny is considered to be roughly equivalent to the combined age range of the Dalgaringa Supersuite and the syntectonic part of the Bertibubba Supersuite (2005–1950 Ma). Two discrete tectonometamorphic episodes have been recognized within this orogeny (D1g and D2g), both of which have been dated directly using metamorphic zircon and monazite. Although D1g has been precisely dated (SHRIMP U–Pb geochronology of metamorphic zircon rims around older detrital grains) from a diatexite at 1997 ± 10 Ma (GSWA 185942, Wingate et al., 2010), field evidence suggests that D1g was a much longer-lived event, possibly spanning the entire age range of the older parts of the Dalgaringa Supersuite (i.e. 2002 ± 3 to 1987 ± 4 Ma; Nelson, 1999a,b). A large number of precise SHRIMP U–Pb ages have been obtained from metamorphic zircon and monazite that grew within pelitic diatexites and semipelitic schists (now retrogressed) during the D2g event (Johnson et al., 2010, 2011). The ages of metamorphic zircon and monazite, irrespective of the lithological composition or geographical location in which they grew, provide an age range for D2g of c. 1965 to c. 1950 Ma, which is coincident with the age range of the syn-tectonic granitic Bertibubba Supersuite. | | | Tectonic Setting | The Glenburgh Orogeny records the tectonomagmatic evolution of an Andean-type arc along the southern margin of a previously assembled Pilbara Craton – Glenburgh Terrane, and the subsequent collision of this entity with the Yilgarn Craton.
The Dalgaringa Supersuite in the Paradise Zone along the southern margin of the Glenburgh Terrane records a near-continual record of continental arc magmatism (Sheppard et al., 2004) and accompanying deformation between c. 2005 and c. 1985 Ma (Occhipinti and Sheppard, 2001). The presence of older, slightly isotopically evolved (Lu–Hf isotope system) detrital zircon within the Quartpot Pelite, suggests that continental arc magmatism (in a proto-Dalgaringa arc) may extend back as far as c. 2080 Ma (Johnson et al, 2010, 2011). The presence of Dalgaringa Supersuite-aged granitic components within the Halfway Gneiss indicate that arc magmatism took place within the Glenburgh Terrane, presumably along its southern margin, so that subduction of oceanic crust was toward the northwest under the Glenburgh Terrane (Sheppard et al., 2004; Johnson et al., 2010, 2011). Within the currently exposed parts of the Dalgaringa Supersuite, deformation associated with D1g appears to have spanned the entire 2005–1985 Ma period. Combined with the moderate- to high-pressure, high-temperature nature of M1g, this tectonomagmatic event is interpreted to represent construction of the continental arc within mid-crustal levels. The Quartpot Pelite of the Camel Hills Metamorphics appears to have been deposited between 2000–1955 Ma (Johnson et al., 2010, 2011) as a result of this deformation.
Juxtaposition of the Quartpot Pelite with lithologies from the opposite side of the oceanic tract (i.e., the Petter Calc-silicate) is interpreted to have occurred during D2g with the Errabiddy Shear Zone representing the suture. Although no relict ophiolitic slices appear to have been preserved, the interleaving of lithologies with different provenance, the pervasive nature of subhorizontal D2g deformation, and the moderate-pressure and moderate- to high-temperature nature of the metamorphism all suggest that D2g/M2g was the result of collision between the Pilbara–Glenburgh Craton with the Yilgarn Craton. This event is precisely dated from the growth of metamorphic zircon and monazite in the highest grade lithologies to between c. 1965 and c. 1950 Ma (Johnson et al., 2010, 2011). Along with D2g/M2g, the coeval granitic Bertibubba Supersuite is the first element common to the northwestern Yilgarn Craton through to the Paradise Zone in the Glenburgh Terrane. | | | | References | Johnson, SP, Sheppard, S, Rasmussen, B, Wingate, MTD, Kirkland, CL, Muhling, JR, Fletcher, IR and Belousova, E 2010, The Glenburgh Orogeny as a record of Paleoproterozoic continent-continent collision: Geological Survey of Western Australia, Record 2010/5, 54p. View Reference | Johnson, SP, Sheppard, S, Rasmussen, B, Wingate, MTD, Kirkland, CL, Muhling, JR, Fletcher, IR and Belousova, EA 2011, Two collisions, two sutures: punctuated pre-1950 Ma assembly of the West Australian Craton during the Ophthalmian and Glenburgh Orogenies: Precambrian Research, v. 189, no. 3–4, p. 239–262, doi:10.1016/j.precamres.2011.07.011. | Nelson, DR 1999a, 142923.1: foliated biotite monzogranite, Glenburgh Homestead; Geochronology Record 343: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Nelson, DR 1999b, 142925.1: biotite monzogranite, Challenger Well; Geochronology Record 312: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Occhipinti, SA and Sheppard, S 2001, Geology of the Glenburgh 1:100 000 sheet: Geological Survey of Western Australia, 1:100 000 Geological Series Explanatory Notes, 37p. View Reference | Occhipinti, SA, Sheppard, S, Passchier, C, Tyler, IM and Nelson, DR 2004, Palaeoproterozoic crustal accretion and collision in the southern Capricorn Orogen: The Glenburgh Orogeny: Precambrian Research, v. 128, p. 237–255. | Pirajno, F, Occhipinti, SA and Swager, CP 2000, Geology and mineralization of the Palaeoproterozoic Bryah and Padbury Basins, Western Australia: Geological Survey of Western Australia, Report 59, 52p. View Reference | Rigby, MJ 2009, Conflicting P-T paths within the Central Zone of the Limpopo Belt: A consequence of different thermobarometric methods?: Journal of African Earth Sciences, v. 54, p. 111–126. | Schulters, JC and Bohlen, SR 1988, The stability of hercynite and hercynite-gahnite spinels in corundum- or quartz-bearing assemblages: Journal of Petrology, v. 30, p. 1017–1031. | Sheppard, S, Occhipinti, SA and Tyler, IM 2004, A 2005-1970 Ma Andean-type batholith in the southern Gascoyne Complex, Western Australia: Precambrian Research, v. 128, p. 257–277. | Wingate, MTD, Kirkland, CL, Johnson, SP and Sheppard, S 2010, 185942.1: pelitic diatexite, Paradise Well; Geochronology Record 861: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference |
| | | | Recommended reference for this publication | Johnson, SP, Sheppard, S and Occhipinti, SA 2020, Glenburgh Orogeny (CG): 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 29 January 2020. | | | | | 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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