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| | | Mutherbukin Tectonic Event (MB) | SP Johnson, FJ Korhonen, S Sheppard, and HNC Cutten | | | | | Event type | deformation: transpressional | Parent event | | Child events | | Tectonic units affected | | Tectonic setting | orogen: intracratonic orogen | Metamorphic facies | | amphibolite: staurolite | amphibolite: sillimanite |
| Metamorphic/tectonic features | folded; gneissose; schistose; sheared |
| | | Summary | The Mutherbukin Tectonic Event affected lithologies primarily from the Mutherbukin Zone in the central Gascoyne Province, although low-grade metamorphism and hydrothermal activity have also affected parts of the overlying sedimentary rocks of the Mount Augustus Sandstone and Edmund Group. The primary expression of the event in the Gascoyne Province is a strong upright schistosity or crenulation schistosity in metasedimentary rocks, and a widely developed foliation or gneissic banding in metamorphosed granites through much of the Mutherbukin Zone. SHRIMP U–Pb dating of monazite, xenotime, and zircon from pelitic schists and granitic gneisses indicates that medium- to high-grade metamorphism, transpression and thin-skinned crustal thickening occurred between c. 1320 and 1270 Ma. The thermal effects of this event lasted for over 100 Ma, with estimates of peak metamorphism defining an apparent thermal gradient of 45°C km⁻¹. The heat source was primerally thickening of radiogenic crust. Peak metamorphism was terminated by transtension and crustal thinning from c. 1210 to 1170 Ma. Low-grade metamorphism, sinistral faulting, transpressional folding, and hydrothermal fluid flow that is recorded in the overlying sedimentary rocks, was synchronous (i.e. between c. 1300 and 1170 Ma) with these deformation and metamorphic events, indicating a strong, dynamic link between events in the middle and upper crust. Although the tectonic drivers for these events are unknown, they took place in similar time frame to far-field events around the Yilgarn Craton margin. | | | Distribution | The 1321–1171 Ma Mutherbukin Tectonic Event affected rocks over a wide area of the Capricorn Orogen, including metasedimentary and meta-igneous rocks of the Gascoyne Province and low-grade metasedimentary rocks of the Mount Augustus and Edmund Basins. The precise distribution of Mutherbukin-aged fabrics and faults is difficult to define because they are hard to distinguish from coaxial structures formed during the 1026–954 Ma Edmundian Orogeny. However, medium- to high-grade mineral assemblages and tectonic fabrics related to the event appear to be mostly confined to the Mutherbukin Zone, which is a 50 km-wide corridor bounded by the Ti Tree and Chalba Shear Zones in the central part of the Gascoyne Province. Medium-grade deformation may also be recorded in narrow shear zones that deform an isolated pluton of Davey Well Granite (P_-DUda-mgmu) within the Minnie Creek batholith (Limejuice Zone) to the north on central LYNDON.
Low-grade sinistral faulting and ?transpressional folding is evident in the overlying low-grade metasedimentary rocks of the Edmund Group. These features are most prevalent in a southeast-trending structural corridor along the southern limb of the Wanna Syncline, ranging from EDMUND in the north to CAYLIE and TANGADEE in the southeast. | | | Description | The main expression of the Mutherbukin Tectonic Event in the Gascoyne Province is a strong upright schistosity in pelitic and semipelitic rocks of the Leake Springs Metamorphics, and a widely developed foliation or gneissic banding within metamorphosed granites. Field evidence for Mutherbukin-age deformation in the Edmund Group sedimentary rocks and underlying Mount Augustus Sandstone is more cryptic. This is because the deformation is of very low metamorphic grade, and is restricted to narrow shear zones and sinistral strike slip faults that were reactivated during the Edmundian Orogeny and Mulka Tectonic Event. However, abundant Mutherbukin-aged hydrothermal monazite and xenotime within these sedimentary rocks indicate that they were subject to low-grade metamorphism and hydrothermal alteration during this event.
In the Gascoyne Province the main structural fabrics trend east-southeast and parallel to the main structural elements of the province. Andalusite-, garnet-, and staurolite-bearing semipelitic schists are prevalent, along with upper amphibolite facies granitic gneisses that locally preserve evidence for in situ melting (Korhonen et al., 2015). Throughout the Mutherbukin Zone, granites of the Durlacher Supersuite, and specifically the Davey Well Granite, are strongly deformed with the formation of a predominant southeast-plunging stretching lineation. These fabrics are particularly well developed on the central part of YINNETHARRA. On LOCKIER a regional-scale (10 km wide by 45 km long) gently, southeast-plunging sheath fold, the Lockier Anticline, is developed within the Durlacher Supersuite granitic rocks (mainly defined by P_-DU-mgnw). The rocks within the sheath fold are strongly deformed and carry pervasive L to L–S fabrics. The preservation and structural continuity of the Mutherbukin-aged fabrics on LOCKIER can be traced across much of the Mutherbukin Zone onto YINNETHARRA where they define a broad dome about 30 km across, known as the 'Yinnetharra Gneiss Dome' (Williams,1986). This trend constitutes the southeasternmost expression of the regional-scale sheath fold defined on LOCKIER. Within the Davey Well Granite, boudinaged lenses and layers of aegirine–augite- or hornblende-bearing metamorphosed alkaline granites, the Tetlow Granite (P_-DUtl-mgi), are preserved. The metagranites are always strongly deformed and contain a subtle compositional layering. Both the fabrics and layering in the metagranites are parallel to those within the enclosing Davey Well Granite which can be correlated with the regional-scale sinistral fabric present throughout the Mutherbukin Zone. The metagranites comprise plagioclase, subordinate aegerine–augite or amphibole, and lesser amounts of quartz (5–12%), epidote, titanite, and allanite. The local presence of grossular and the replacement of pyroxene with amphibole indicate that the pervasive fabrics in the Mutherbukin Zone on YINNETHARRA and EUDAMULLAH developed in the mid-amphibolite facies.
In the 'Nick Belt' of the Mutherbukin Zone on MOUNT SANDIMAN, the lower grade schists, carry a predominant foliation (S1u) defined by muscovite and flattened quartz grains, and lineation (L1u) which is commonly defined by 1–5 mm-long, elongate magnetite and andalusite porphyroblasts. In the medium-grade schists, in the southern part of the 'Nick Belt', this S1u–L1u fabric is overgrown by randomly oriented, coarse-grained staurolite and garnet porphyroblasts, suggesting that peak metamorphism outlasted any shear-dominated deformation. Peak pressure (P)–temperature (T) estimates, based on well-constrained pseudosections, indicate condictions of < 6.4 kbar at 460–550°C for the chlorite–magnetite schists and 3.6–6.5 kbar at 535–650°C for the staurolite(–garnet)-bearing lithologies (Korhonen et al., 2015). In situ U–Th–Pb dating of monazite and xenotime from the low- to medium-grade schists in the Nick Belt, yields dates between c. 1206 and 1187 Ma, interpreted to record the timing of peak metamorphism (Korhonen et al., 2015).
In the hinge zone of the Lockier Anticline on LOCKIER, 3.7 km to the northwest of McCarthy Well (SXSGAS008458, Zone 50, MGA 372898E 7283465N), coarse-grained porphyritic biotite metamonzogranite of the Davey Well Granite (part of the 1680–1620 Ma Durlacher Supersuite) has been strongly and heterogeneously deformed at high metamorphic grade with the in situ generation of small melt pockets and veins of massive biotite pegmatite. Shear sense indicators associated with the L1u–S1u fabric indicate dextral transpression, with regional-scale top-to-the-west transport (Korhonen et al., 2015). This fabric is truncated at a low to moderate angle by narrow, steeply-dipping extensional (or transtensional) shear zones (S2u) that host small pockets and veins of massive biotite pegmatite which are interpreted as in situ melt. Commonly these veins form in extensional boudin necks implying that they developed by melting of the granitic host in situ. Locally, where the S2u is well developed, it is coaxial with the S1u gneissic fabric, forming a single composite gneissic fabric (S1u-S2u). Peak P–T conditions were attained during the generation of in situ melt veins (S2u) at 4.4–7 kbar and > 650°C (Korhonen et al., 2015). U–Pb SHRIMP dating of different zircon growth domains extracted from the melt pockets indicate that the pervasive L1u–S1u gneissic fabric was probably generated at 1321 ± 40 Ma, whilst in situ melting and, the generation of extensional S2U fabrics, took place at 1200 ± 3 Ma (GSWA 185926, Wingate et al., 2013; Korhonen et al., 2015).
A 2.5 km-long fault slice of garnet- and staurolite-bearing pelitic schist (P_-LS-mmsg) within the Davey Well Granite at Tommie Well on southeastern EUDAMULLAH contains two metamorphic fabrics. The first is crenulated and folded by an easterly trending, upright schistosity, which is the dominant fabric in the rocks. In some instances the first fabric is obliterated in the matrix, being preserved only as folded inclusion trails within staurolite porphyroblasts. Since this fault lens is isolated from the main structural elements in the Mutherbukin Zone, the two fabrics cannot be confidently linked with the regional S1u and S2u fabrics, and so the structural evolution is only described on a local scale (i.e. S1 and S2). Peak P–T conditions are estimated at 3.6–6.2 kbar and 550–640°C (Korhonen et al., 2015). U–Th–Pb SHRIMP dating of monazite intergrown with staurolite, as well as inclusions within staurolite, and as grains parallel to the S2 foliation yielded an age of c. 1281 Ma (Korhonen et al., 2015). Monazite found only as grains within, and parallel to, the S2 foliation provided an age of c. 1243 Ma (Korhonen et al., 2015). U–Th–Pb SHRIMP dating of xenotime yielded a range of poorly constrained ages between c. 1353 and 1312 Ma, and c. 1210 and 1159 Ma (Korhonen et al., 2015). Several monazites also yielded a range of younger ages between c. 1215 and 1143 Ma, but these may represent grains which have undergone Pb loss (Korhonen et al., 2015). These data imply that the polyphase structural evolution of this fault lens is more complicated than other units within the Mutherbukin Zone, and it is possible that this slice represents a piece of crust that was decoupled from other units in the zone and that its evolution was linked directly to punctuated movements on the Ti Tree Shear Zone.
Field evidence for Mutherbukin-aged deformation in the Edmund Basin is more limited due to the low to very low grade nature of metamorphism. However, rocks of both the Edmund and Mount Augustus Basins contain abundant 1375–1220 Ma old hydrothermal monazite and xenotime (Rasmussen et al., 2010; Zi et al., 2015). In addition, hydrothermal xenotime from the Tangadee Rhyolite has been dated at c. 1235 Ma (Rasmussen et al., 2010), and pyrite from the red zone of the Abra deposit returned a Re–Os age of c. 1284 Ma (Pirajno et al., 2010). Surface geological mapping in the eastern part of the basin, for example on CAYLIE, demonstrates that many faults within the Edmund Group have large, sinistral strike-slip offsets, but only small offsets in the overlying Collier Group, suggesting pre-Edmundian Orogeny (1026–954 Ma) movements (Cutten et al., 2011). Although faulting in the Edmund Group is brittle in nature, rendering fault movements hard to date, a fault gouge that displaces sandstone and siltstone beds of the Kiangi Creek Formation on TANGADEE has been dated at 1171 ± 25 Ma (Zwingmann et al., 2012), confirming fault movement during the Mutherbukin Tectonic Event. The date was obtained from authigenic illite using the ⁴⁰K/⁴⁰Ar method. Additional structural data on the southern limb of the Wanna Syncline on EDMUND show a greater intensity of faults within the Edmund Group. The deep crustal seismic reflection survey of the Capricorn Orogen (Johnson et al., 2011; Johnson et al., 2013) shows that these faults are small thrusts with accompanying hanging wall anticlines, preserved in the Edmund Group sedimentary rocks. These features are not replicated in the overlying Collier Group, implying that deformation is related to the Mutherbukin Tectonic Event, and that the Collier Group could not have been deposited until after this event (i.e. after c. 1170 Ma). | | | | | | Geochronology | | | Mutherbukin Tectonic Event | Maximum age | Minimum age | Age (Ma) | 1321 ± 40 | 1171 ± 4 | Age | Mesoproterozoic | Mesoproterozoic | Age data type | Isotopic | | References | | |
| The age of deformation, metamorphism and hydrothermal alteration associated with the Mutherbukin Tectonic Event has been well constrained by the U–Th–Pb SHIRMP dating of zircon and phosphate minerals (monazite and xenotime), Re–Os dating of sulfides (pyrite), and K–Ar dating of sericite from fault zones, from various lithologies throughout the Mutherbukin Zone (Korhonen et al., 2015; Zi et al., 2015; Rasmussen et al., 2010; Pirajno et al., 2010).
Along the northern margin of the Mutherbukin Zone of the Gascoyne Province, numerous low- to medium-grade metasedimentary and meta-igneous units have been dated. Three samples from widely spaced localities in the 'Nick Belt' (GSWA 36493, 188998, 188999) on MOUNT SANDIMAN yielded SHRIMP U–Th–Pb monazite dates ranging from c. 1220 to 1187 Ma (Korhonen et al., 2015). In detail, 16 analyses of seven monazite grains from GSWA 36493 yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1206 ± 6 Ma (MSWD = 0.84); two analyses of two monazite grains from GSWA 188999 yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1220 ± 18 Ma (MSWD = 0.20), this sample also contained a significant component of older grains that yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1750 ± 35 Ma (MSWD = 0.20); and 24 analyses of 10 monazite grains within GSWA 188999 yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1187 ± 7 Ma (MSWD = 1.50). These dates are interpreted to record peak lower amphibolite to greenschist facies metamorphism that was coincident with regional-scale D2 transtensional deformation (Korhonen et al., 2015).
Strongly deformed and metamorphosed biotite metamonzogranite of the Davey Well Granite from LOCKIER (GSWA 195826), yielded abundant metamorphic zircon rims (around older igneous zircon cores) dated at 1321 ± 40 Ma (MSWD = 0.61; five analyses of five rims) and 1200 ± 3 Ma (MSWD = 1.3; 13 analyses of four rims; Wingate et al., 2013). The older date at c. 1320 Ma is interpreted to record the onset of prograde compressional (or transpressional) deformation and metamorphism that was coincident with the production of the S1u gneissic fabrics (both L and S). The younger c. 1200 Ma date is interpreted to record the timing of crystallization of in situ melt veins that formed during peak metamorphism, with the production of regionally-developed extensional (or transtensional) S2u fabrics (Korhonen et al., 2015).
Pelitic schists (GSWA 88436) from a 2.5 km long fault slice at Tommie Well on EUDAMULLAH, yielded weighted mean ²⁰⁷Pb*/²⁰⁶Pb* dates at 1281 ± 3 Ma (MSWD = 1.20; 23 analyses of 11 monazites) and 1243 ± 7 Ma (MSWD = 0.76; 7 analyses of 5 monazite grains). These dates are interpreted to record prolonged or polyphase metamorphic events associated with punctuated movements on the Ti Tree Shear Zone (Korhonen et al., 2015).
Farther east, on the northern part of YINNETHARRA, a hydrothermally altered pelitic schist at the contact with a pegmatite dyke was sampled for phosphate geochronology. The sample (GSWA 88475) yielded a range of monazite ages from c. 1790 to 933 Ma (Korhonen et al., 2015). The oldest component, obtained from 24 analyses yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1780 ± 2 Ma (MSWD = 1.20), the next youngest component obtained from 10 analyses, yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1171 ± 4 Ma (MSWD = 1.30), and the youngest component obtained from six analyses, yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 958 ± 16 (MSWD = 3.00). Although these different age components are difficult to interpret, the youngest component at c. 958 Ma most likely represents the age of the pegmatite vein that intrudes the schist as this dyke forms part of the 995–939 Ma Thirty Three Supersuite (P_-TT-g). The two older age components may represent periods of deformation, fabric formation and metamorphism, one of which is coincident with the Mutherbukin Tectonic Event (Korhonen et al., 2015).
In the 'Nardoo Belt' on northern YINNETHARRA, a sample of andalusite-bearing pelitic schist was collected for phosphate geochronology. Fourteen analyses of 10 monazite grains from the sample (GSWA 46981) yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1272 ± 9 Ma (MSWD = 1.30) interpreted to record the timing of peak metamorphism (Korhonen et al., 2015). Additionally, seven analyses were made on three xenotime grains, which yielded a range of ²⁰⁷Pb*/²⁰⁶Pb* dates between c. 1572 and 1168 Ma (Korhonen et al., 2015).
Various dating methods have yielded age ranges from c. 1375 to 1171 Ma for the unconformably overlying low-grade metasedimentary rocks of the Mount Augustus Sandstone and Edmund Group. Hydrothermal monazite from a single sample of the Mount Augustus Sandstone (GSWA 156589) on MOUNT AUGUSTUS returned a U–Th–Pb SHIRMP date of 1300 ± 10 Ma (Rasmussen, preliminary data). Extensive U–Th–Pb SHIRMP dating of xenotime and monazite from the Abra polymetallic deposit and surrounding lithologies in the eastern part of the Capricorn Orogen on CALYIE, has yielded numerous dates between c. 1375 and 995 Ma (Zi et al., 2015; Rasmussen et al., 2010). Hydrothermal xenotime from within the black zone, where it is intergrown with hematite, galena and magnetite yielded a range of dates between c. 1610 and 1590 Ma, suggesting that the Abra deposit was precipitated during a prolonged period of hydrothermal activity, during the deposition of the lower part of the Edmund Basin (Zi et al., 2015; Johnson et al., 2015). Hydrothermal monazite from the red zone of the deposit and the overlying (and distal) unmineralized strata, are intergrown with low-grade alteration assemblages containing barite, K–feldspar, quartz and chlorite (Zi et al., 2015). Several distinct age components have been identified at 1375 ± 14 Ma (MSWD = 0.99; 16 analyses), 1221 ± 14 Ma (MSWD = 1.04, five analyses), and 995 ± 18 Ma (MSWD = 1.30, six analyses), all of which are interpreted to record the timing of regional-scale hydrothermal alteration events associated with the reactivation of the Quartzite Well – Lyons River Fault system (Zi et al., 2015). Similar ages have been obtained from hydrothermal xenotime from the Tangadee Rhyolite on TANGADEE (GSWA 149020) which yielded a weighted mean ²⁰⁷Pb*/²⁰⁶Pb* date of 1235 ± 19 Ma (MSWD = 0.94, nine analyses; Rasmussen et al., 2010) and a Re–Os age obtained from pyrite (GSWA 187840) in the red zone of the Abra polymetallic deposit which yielded a date of 1284 ± 47 Ma (Pirajno et al., 2010). The youngest date from the Edmund Basin was obtained by the potassium–argon dating of sericite from a fault gouge, which sinistrally displaces rocks of the Kiangi Creek Formation on TANGADEE (GSWA 189218). The sample yielded a date of 1171 ± 25 Ma (Zwingmann et al., 2012).
The oldest and youngest dates obtained from the Edmund and Mount Augustus Basins, at c. 1375 and 995 Ma, respectively, are outside the range of deformation and metamorphic ages obtained for the Gascoyne Province basement between c. 1321 and 1171 Ma. The younger date at c. 995 Ma is coincident with deformation and metamorphism during the 1026–954 Ma Edmundian Orogeny, but the older date at c. 1375 Ma does not correlate with any known events in the orogen. Therefore, it is possible that this is a very localized hydrothermal event, related to local movements on the Quartzite Well – Lyons River Fault system, and is thus not considered part of the orogen-wide Mutherbukin Tectonic Event, where there is a good correlation in the timing of tectonic events between the mid and upper crust. | | | Tectonic Setting | The 1321–1171 Ma Mutherbukin Tectonic Event marks an important and significant period of intracontinental reactivation within the Capricorn Orogen. The event represents a period of thin-skinned, upper crustal thickening (D1u) that was initiated at c. 1320 Ma (Korhonen et al., 2015). The thickened crustal profile was maintained for at least 100 Ma, before being rapidly thinned during extensional or transtensional deformation (D2u) between c. 1210 and 1171 Ma. The absence of magmatism during this event distinguishes it from the other tectonothermal events (i.e. ‘orogenies’) associated with the prolonged reworking of the Capricorn Orogen.
Thermal modelling has demonstrated that the preservation of thickened radiogenic crust in the orogen between c. 1320 and 1210 Ma, would have acted as a 'thermal lid' allowing for prolonged conductive heating within the crustal profile, and the growth of 'peak' metamorphic mineral phases (including monazite and xenotime) over the entire 100 Ma time period (Korhonen et al., 2015). The thermal model also predicts that metamorphic temperatures would remain below the granitic wet solidus for up to 140 Ma of sustained thickened crust; therefore, significant crustal melts could not be produced from the upper to mid crustal rocks during the time scales involved. Although the lower-middle to lower crustal rocks of the Glenburgh Terrane and the MacAdam Seismic Province are predicted to reach temperatures up to 800°C, these units are the dry, refractory residuals of earlier Paleoproterozoic granite production and would require even higher temperatures to produce significant crustal melts.
The presence of an insulating thermal lid is a fundamental feature of the Mutherbukin Tectonic Event. In this case, a thickened sedimentary basin with elevated concentrations of high heat-producing elements (HPE) would have acted as a thermal lid for at least 100 Ma. The elevated thermal gradient would weaken the lithosphere, allowing the crust to deform horizontally. This weakened lithosphere would also not be able to sustain elevated topography, implying low erosion rates (e.g. McLaren et al., 2005). Another effect of a weak lithosphere is that it will be more responsive to far-field stresses (e.g. Sandiford and McLaren, 2002). Importantly, these far-field stresses could be the tectonic driving force for such intracrustal events. Although the causes for the tectonism are unclear, it is noted that deformation and metamorphism were coincident with Stages I (1330–1260 Ma) and II (1225–1140 Ma) of the Albany–Fraser Orogeny, the 1345–1293 Ma Mount West Orogeny, the 1225–1150 Ma Musgrave Orogeny in the west Musgrave Province, and the 1205–1150 Ma Darling Orogeny in the Pinjarra Orogen (Johnson 2013). The synchronicity of events around the margin of the entire Yilgarn Craton imply continent-scale tectonics, which may relate to global-scale plate reorganizations during the break-up of the Nuna Supercontinent (Johnson 2013). | | | | References | Cutten, HN, Thorne, AM and Johnson, SP 2011, Geology of the Edmund and Collier Groups, in Capricorn Orogen seismic and magnetotelluric (MT) workshop 2011: extended abstracts edited by Johnson, SP, Thorne, AM and Tyler, IM: Geological Survey of Western Australia, Perth, Record 2011/25, p. 41–48. | Johnson, SP 2013, The birth of supercontinents and the Proterozoic assembly of Western Australia: Geological Survey of Western Australia, Perth, Western Australia, 78p. View Reference | Johnson, SP, Thorne, AM and Tyler, IM 2011, Capricorn Orogen seismic and magnetotelluric (MT) workshop 2011: extended abstracts: Geological Survey of Western Australia, Perth, Record 2011/25, 120p. View Reference | Johnson, SP, Thorne, AM, Tyler, IM, Korsch, RJ, Kennett, BLN, Cutten, HN, Goodwin, J, Blay, OA, Blewett, RS, Joly, A, Dentith, MC, Aitken, ARA, Holzschuh, J, Salmon, M, Reading, A, Heinson, G, Boren, G, Ross, J, Costelloe, RD and Fomin, T 2013, Crustal architecture of the Capricorn Orogen, Western Australia and associated metallogeny: Australian Journal of Earth Sciences, v. 60, no. 6–7, p. 681–705, doi:10.1080/08120099.2013.826735. | Johnson, SP, Zi, J, Rasmussen, B, Muhling, JR, Fletcher, IR, Dunkley, DJ, Thorne, AM, Cutten, HN and Korhonen, FJ 2015, Abracadabra - dating hydrothermal mineralization and fluid flow in a long-lived crustal structure, in GSWA 2015 extended abstracts: promoting the prospectivity of Western Australia: Geological Survey of Western Australia, Record, p. 1–4. | Korhonen, FJ, Johnson, SP, Fletcher, IR, Rasmussen, B, Sheppard, S, Muhling, JR, Dunkley, DJ, Wingate, MTD, Roberts, MP and Kirkland, CL 2015, Pressure–temperature–time evolution of the Mutherbukin Tectonic Event, Capricorn Orogen: Geological Survey of Western Australia, Report 146, 64p. View Reference | McLaren, S, Sandiford, M and Powell, R 2005, Contrasting styles of Proterozoic crustal evolution: A hot-plate tectonic model for Australian terranes: Geology, v. 33, p. 673–676. | Pirajno, F, Thorne, AM, Mernagh, TP, Creaser, RA, Hell, A and Cutten, H 2010, The Abra deposit: a polymetallic mineral system in the Edmund Basin, Capricorn Orogen, Western Australia, in 13th quadrennial IAGOD symposium proceedings - abstracts volume edited by Cook, NJ: Giant Ore Deposits Down-Under, Adelaide, South Australia, 6-9 April 2010: International Association on Genesis of Ore Deposits (IAGOD), p. 112–114. | Rasmussen, B, Fletcher, IR, Muhling, JR, Thorne, AM, Cutten, HN, Pirajno, F and Hell, A 2010, In situ U–Pb monazite and xenotime geochronology of the Abra polymetallic deposit and associated sedimentary and volcanic rocks, Bangemall Supergroup, Western Australia: Geological Survey of Western Australia, Record 2010/12, 31p. View Reference | Sandiford, M and McLaren, S 2002, Tectonic feedback and the ordering of heat producing elements within the continental lithosphere: Earth and Planetary Science Letters, v. 204, no. 1–2, p. 133–150. | Williams, SJ 1986, Geology of the Gascoyne Province, Western Australia: Geological Survey of Western Australia, Report 15, 85p. View Reference | Wingate, MTD, Kirkland, CL and Johnson, SP 2013, 195826.1: monzogranitic gneiss, McCarthy Well; Geochronology Record 1104: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference | Zi, J, Rasmussen, B, Muhling, JR, Fletcher, IR, Thorne, AM, Johnson, SP, Cutten, HN, Dunkley, DJ and Korhonen, FJ 2015, In situ U–Pb geochronology of xenotime and monazite from the Abra polymetallic deposit in the Capricorn Orogen, Australia: dating hydrothermal mineralization and fluid flow in a long-lived crustal structure: Precambrian Research, v. 260, p. 91–112, doi:10.1130/G30785.1. | Zwingmann, H, Wingate, MTD, Cutten, HN, Todd, AJ and Kirkland, CL 2012, 189218.1: siltstone fault-rock, Brumby Creek; Geochronology Record 1117: Geological Survey of Western Australia, <www.dmpe.wa.gov.au/geochron>. View Reference |
| | | | Recommended reference for this publication | Johnson, SP, Korhonen, FJ, Sheppard, S and Cutten, HNC 2022, Mutherbukin Tectonic Event (MB): 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 March 2022. | | | | | 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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