West Yilgarn

The West Yilgarn project team continues to carry out geoscientific investigations including seamless detailed mapping, to advance our understanding of Archean granite–greenstone terrains, and to interpret their tectonic evolution and prospectivity.

The West Yilgarn project area and simplified geological map showing available interpreted bedrock geology, 1:100 000 Geological Series maps and digital updates. The yellow outline identifies the knowledge gap of the western margin of the Yilgarn Craton.

The project area includes the Youanmi, Narryer and South West Terranes as well as the terrane boundary with the Eastern Goldfields Superterrane to the east. Early mapping by the Geological Survey of Western Australia (GSWA) in the 1970s and 1980s included 1:250 000-scale maps and Explanatory Notes, and a number of early Reports. Systematic 1:100 000-scale field mapping from the late 1990s to the present has produced annually updated digital packages (including more than 55 first and second edition maps) and Explanatory Notes for lithostratigraphic units, as well as numerous Reports and Records outlining the complex and protracted tectonic history of this part of the Yilgarn Craton.

Mapping of the western Yilgarn Craton is ongoing, creating new interpreted bedrock geology (IBG) digital layers as well as regularly updating, enhancing and improving earlier map interpretations in critical, problematic or less well-studied regions. The study area is fully covered by recent aeromagnetic and radiometric surveys (25–400 m line spacing),
2.5 km spaced gravity, and Landsat TM and DEM-derived imagery. Coverage also includes crustal-scale geophysical datasets including seismic reflection and magnetotelluric (MT) data, regional- and local-scale 3D models and regional-scale passive seismic data. Together with widespread SHRIMP U–Pb zircon geochronology, whole-rock and mineral isotope geochemistry, structural data and novel geochronology methods, these data help define the tectonic, depositional and mineralization history of the western Yilgarn Craton.

Access GSWA publications through the DMIRS eBookshop or from the lists below. The West Yilgarn 2022 Geological Information Series (GIS) data package is the most up-to-date compilation for the project, which contains digital geology layers at a variety of scales, cross-sections, field observation data, geophysical images, satellite images, geochemistry data and an extensive compilation of GSWA publications.

Geological evolution of the western Yilgarn Craton

Updated stratigraphic framework for the Murchison and Southern Cross Supergroups showing relative probability curves for volcanic, plutonic and detrital zircon ages

The western Yilgarn Craton consists of extensive Archean granite–greenstone terrain and high-grade gneisses that contain significant deposits of gold, iron ore, nickel, copper, lead, zinc, tungsten, molybdenum, bismuth, vanadium, titanium, beryllium, lithium, tin, tantalum and uranium — with clear potential for the discovery of more deposits. The Youanmi Terrane forms 58% by area of the 850 x 1000 km Yilgarn Craton with the Narryer and South West Terranes forming 1.5 and 5%, respectively. These terranes have a long and complex geological history and an understanding of the tectonic evolution of the region, including its structure, stratigraphy and magmatism, is essential to understanding the controls on formation and distribution of mineralization.

Narryer Terrane

The Narryer Terrane in the northwest, contains the oldest rocks in the Yilgarn Craton and shares a tectonic contact with the Youanmi Terrane. The oldest rocks identified in the Narryer Terrane are 3.73 Ga migmatitic gneiss and layered mafic rocks; however, detrital zircon in quartzite and conglomerate at Mount Narryer and Jack Hills include zircons older than 4.0 Ga that pre-date any known rocks on Earth. These outstanding features have drawn considerable scientific attention to the felsic components of Narryer geology along the proposed terrane boundary, but the geology of the internal parts of the Narryer Terrane and of the supracrustal sequences are, in contrast, very poorly known. Greenstones in the Narryer Terrane are restricted to several belts of strongly deformed and metamorphosed rocks yielding depositional ages between 3.1 and 2.7 Ga. Proterozoic volcanic and deformational episodes are also poorly studied.

Youanmi Terrane

The Youanmi Terrane in the western part of the Yilgarn Craton comprises an extensive Archean granite–greenstone terrain with a long and complex geological history. The Youanmi Terrane greenstones, incorporating the older Madoonga and Gossan Hill Formations and the voluminous Norie, Polelle and Glen Groups, were deposited between 2.99 and 2.71 Ga. Felsic plutonic rocks intruded during each of these periods of volcano-sedimentary deposition and as voluminous syntectonic, synorogenic plutons along crustal-scale transpressional shear zones during the 2.73 – 2.65 Ga Yilgarn orogeny. Granitic magmatism continued during the late- to post-orogenic stages (2.64 – 2.60 Ga) that led to cratonization of the Yilgarn lithosphere.

Much of the regional mapping and additional geoscientific work conducted so far in the Youanmi Terrane has concentrated on its Neoarchean greenstone sequences and on the relationship between synorogenic magmatism, metamorphism and deformation along large-scale shear zones. However, there is a large temporal gap in the understanding of the crustal evolution of the older components of the Yilgarn Craton, including the overall lithospheric architectural evolution during the Mesoarchean from 3.1 to 2.9 Ga. The Youanmi Terrane hosts most of the craton’s rocks of this period but geoscience data coverage and map detail is generally variable and incomplete.

South West Terrane

As a result of work and interpretations that emerged from the 2020–21 Southwest Yilgarn Accelerated Geoscience Program (AGP), the boundary between the Youanmi and South West Terranes has been shifted by about 200 km towards the southwest. The redefined South West Terrane is currently regarded as a Neoarchean crustal entity, dominated by rocks younger than c. 2.7 Ga. There is no formal stratigraphy for the greenstone successions in the South West Terrane. In the hangingwall of the redefined terrane boundary, we identify the Corrigin Tectonic Zone (CTZ), consisting of a 50–150 km-wide zone of southwest-verging, anastomosing shear zone system formed in transpression under granulite facies conditions and between c. 2665 and 2635 Ma. This boundary forms an obvious new search space for mineral exploration.

Planned work program

The 2022 West Yilgarn GIS package integrated the interpreted bedrock geology from the Youanmi 2020 GIS package and the southwest Yilgarn 2021 Geological Exploration Package. To complete this amalgamation in the coming years, our focus is on data acquisition and interpretation along the western margin of the Yilgarn Craton.

Fieldwork related to the 2022–23 work program will prioritize observations, sampling and initial interpretations, aimed at consolidating the interpreted kinematics and age of major shear zones of the Corrigin Tectonic Zone, the Darling Fault and the Narryer/Youanmi Terrane boundary.

Collaborative projects

A new collaborative PhD project with The University of Western Australia will investigate the terrane boundary between the Youanmi and South West Terranes in the Toodyay–Northam area. The project commenced in February 2022 and is projected to end in 2025.

Detailed fieldwork focusing on the Late Archean, Proterozoic and Phanerozoic tectonic evolution of the western Yilgarn Craton margin commenced during the 2020–21 AGP and will be extended to the region around Harvey Dam, aiming at deciphering the Archean history of the western Yilgarn margin along the Darling Fault.

Cooperative projects with various universities will continue, and include geochemical, metamorphic and structural studies in the northern Youanmi Terrane, 3D modelling in the western Youanmi Terrane, and structural and isotopic studies in the Narryer Terrane.

Products planned for release

Explanatory notes update for Yilgarn Craton granites and Youanmi Terrane greenstones
Sedimentological investigation of the Mougooderra Formation, Youanmi Terrane (Record)
Structural evolution and quartz c-axis crystallographic preferred orientation of major Yilgarn shear zones (Report)
Formation of the Yilgarn protocraton by rift-related magmatism from 3.01 to 2.92 Ga (Report)
Sixth International Archean Symposium: Fieldguide to the terrane boundary between the Youanmi and South West Terranes of the Yilgarn Craton: Three-day excursion for the 6IAS conference, July 2023 (Record)
Sixth International Archean Symposium: A traverse across the northern Yilgarn Craton in Western Australia — from the Jack Hills to the Youanmi Terrane (Record)

Well-exposed granitic rocks of the Bald Rock Supersuite in the northern part of the Youanmi Terrane

The Windimurra vanadium pit, upper zone of the c. 2.81 Ga Windimurra Igneous Complex, Meeline Suite, Annean Supersuite

The c. 2.96 Ga Kynea Migmatite (Thundelarra Supersuite) at the core of the Yalgoo dome

Platy pyroxene spinifex texture in siliceous high-magnesium basalt of the Polelle Group, Murchison Supergroup, Polelle Syncline

Elliptical mafic clots in sanukitoid of the Annean Supersuite, northern Youanmi Terrane

Explanatory Notes

Detailed descriptions of all lithological units in the Youanmi Terrane can be accessed through the Explanatory Notes System (ENS).

Reports, Bulletins and Annual Reviews

Records

Field guides

Maps — 1:100 000 Geological Series

For a full list of maps please follow the link

link

Non-series maps

3D Geomodel Series

Student theses

Virtual tours

External publications

Year	Title	Details
2022	Greenstone burial–exhumation cycles at the late Archean transition to plate tectonics	Zibra, I, Kemp, D, Smithies, RH, Rubatto, TK, Korhonen, FJ, Haemmerli, J, Johnson, TE, Gessner, K, Weinberg, RF Nature Communications 13 (1), 7893 https://doi.org/10.1038/s41467-022-35208-2
2021	Crustal rejuvenation stabilised Earth’s first cratons	Mulder, JA, Nebel, O, Gardiner, NJ, Cawood, PA, Wainwright, AN, Ivanic TJ Nature Communications 12:3535 https://doi.org/10.1038/s41467-021-23805-6
2020	Archean boninite-like rocks of the Northwestern Youanmi Terrane, Yilgarn Craton: Geochemistry and Genesis	Lowrey, JR, Ivanic, TJ, Wyman, D, Roberts, MP Journal of Petrology, 1–38 https://doi.org/10.1093/petrology/egaa002
2020	Incremental Growth of Layered Mafic-Ultramafic Intrusions	Nebel, O, Sossi, PA, Ivanic, TJ, Bénard, A, Gardiner, NJ, Langford, RL, Arculus, RJ Frontiers in Earth Science 8, Article 2 https://doi.org/10.3929/ethz-b-000409270
2020	Neoarchean structural evolution of the Murchison Domain (Yilgarn Craton)	Zibra, I Precambrian Research 343, 105719 https://doi.org/10.1016/j.precamres.2020.105719
2020	Regional-scale polydiapirism predating the Neoarchean Yilgarn Orogeny	Zibra, I, Lu, Y, Clos, F, Weinberg, RF, Peternell, M, Wingate, MTD, Prause, M, Schiller, Tilhac, MR Tectonophysics 779, 228375 https://doi.org/10.1016/j.tecto.2020.228375
2020	Neoarchean synmagmatic crustal extrusion in the transpressional Yilgarn Orogen	Zibra, I, Weinberg, RF and Peternell, M Tectonics, v. 39, no. 2 https://doi.org/10.1029/2019TC005947
2019	Archean diapirism recorded by vertical sheath folds in the core of the Yalgoo Dome, Yilgarn Craton	Clos, F, Wienberg, RF, Zibra, I, Fenwick, MJ Precambrian Research 320, 391–402 https://doi.org/10.1016/j.precamres.2018.11.010
2019	Magmatic and anatectic history of a large Archean diapir: Insights from the migmatitic core of the Yalgoo Dome, Yilgarn Craton	Clos, F, Wienberg, RF, Zibra, I, Schwindinger, M Lithos 338–339, 18–33 https://doi.org/10.1016/j.lithos.2019.04.012
2019	Dating hypogene iron mineralization events in Archean BIF at Weld Range, Western Australia: insights into the tectonomagmatic history of the northern margin of the Yilgarn Craton	Duuring, P, Santos, JOS, Fielding, IOH, Ivanic, TJ, Hagemann, SG, Angerer, T, Lu, Y, Roberts, M, Choi, J Mineralium Deposita https://doi.org/10.1007/s00126-019-00930-3
2019	No evidence for high-pressure melting of Earth's crust in the Archean	Smithies, RH, Lu, Y, Johnson, TE, Kirkland, CL, Cassidy, KF, Champion, DC, Mole, DR, Zibra, I, Gessner, K, Sapkota, J, de Paoli, MC and Pujol, M Nature Communications, v. 10 https://doi.org/10.1038/s41467-019-13547-x
2019	2.8 Ga Subduction-related magmatism in the Youanmi Terrane and a revised geodynamic model for the Yilgarn Craton	Wyman, DA Precambrian Research 327, 14–33 https://doi.org/10.1016/j.precamres.2019.02.008
2018	Two distinct origins for Archean greenstone belts	Smithies, RH, Ivanic, TJ, Lowrey, JR, Morris, PA, Barnes, SJ, Wyche, S, Lu, Y Earth and Planetary Science Letters 487, 106–116 https://doi.org/10.1016/j.epsl.2018.01.034
2018	The ultimate fate of a synmagmatic shear zone: interplay between rupturing and ductile flow in a cooling granite pluton	Zibra, I, White, JC, Menegon, L, Dering, G and Gessner, K Journal of Structural Geology, v. 110, p. 1–23, https://doi.org/10.1016/j.jsg.2018.02.001
2017	The Windimurra Igneous Complex: an Archean Bushveld?	Ivanic, TJ, Nebel, O, Murdie, RE, Brett, J Geological Society of London Special Publication 453, 1–36 https://doi.org/10.1144/SP453.1
2017	Platy pyroxene: new insights into spinifex texture	Lowrey, JR, Ivanic, TJ, Wyman, D, Roberts, MP Journal of Petrology, 58, 1671–1700 https://doi.org/10.1093/petrology/egx069
2017	The~ 2730 Ma onset of the Neoarchean Yilgarn Orogeny	Zibra, I, Clos, F, Weinberg, RF, Peternell, M Tectonics 36, 1787–1813 https://doi.org/10.1002/2017TC004562
2017	On thrusting, regional unconformities and exhumation of high-grade greenstones in Neoarchean orogens. The case of the Waroonga Shear Zone, Yilgarn Craton	Zibra, I, Korhonen, FJ, Peternell, M, Weinberg, RF, Romano, SS, Bragae, R, De Paoli, MC, Roberts, MP Tectonophysics 712–713, 362–395 https://doi.org/10.1016/j.tecto.2017.05.017
2016	Photograph of the month	Zibra, I and Weinberg, RF Journal of Structural Geology, v. 91, p. iii–iv https://doi.org/10.1016/S0191-8141(16)30146-8
2015	The influence of phase and grain size distribution on the dynamics of strain localization in polymineralic rocks	Czaplinska, D, Piazolo, S and Zibra, I Journal of Structural Geology, v. 72, p. 15–32, https://doi.org/10.1016/j.jsg.2015.01.001
2015	A new period of volcanogenic massive sulfide formation in the Yilgarn: a volcanological study of the ca 2.76 Ga Hollandaire VMS deposit, Yilgarn Craton, Western Australia	Hayman, PC, Hull, SE, Cas, RAF, Summerhayes, E, Amelin, Y, Ivanic, TJ, Price, D Australian Journal of Earth Sciences 62, 189–210 https://doi.org/10.1080/08120099.2015.1011399
2015	A review of volcanic-hosted massive sulfide (VHMS) mineralization in the Archaean Yilgarn Craton, Western Australia: Tectonic, stratigraphic and geochemical associations	Hollis, SP, Yeats, CJ, Wyche, S, Barnes, SJ, Ivanic, Belford, SM, Davidson, GJ, Roache, AJ, Wingate, MTD Precambrian Research 260, 113–135 https://doi.org/10.1016/j.precamres.2014.11.002
2015	Heterogeneously hydrated mantle beneath the late Archean Yilgarn Craton	Ivanic TJ, Nebel, O, Jourdan, F, Faure, K, Kirkland, CL, Belousova, EA Lithos, 238, 76–85 https://doi.org/10.1016/j.lithos.2015.09.020
2014	Structure and timing of Neoarchean gold mineralization in the Southern Cross district (Yilgarn Craton, Western Australia) suggest leading role of late Low-Ca I-type granite intrusions	Doublier, MP, Thébaud, N, Wingate, MTD, Romano, SS, Kirkland, CL, Gessner, K, Mole, DR, Evans, N Journal of Structural Geology 67, 205–221 https://doi.org/10.1016/j.jsg.2014.02.009
2014	Melting of a subduction-modified mantle source: A case study from the Archean Marda Volcanic Complex, central Yilgarn Craton, Western Australia	Morris, PA, Kirkland, CL Lithos 190–191, 403–419 https://doi.org/10.1016/j.lithos.2013.11.016
2014	Geochronological constraints on nickel metallogeny in the Lake Johnston belt, Southern Cross Domain	Romano, SS, Thébaud, N, Mole, DR, Wingate, MTD, Kirkland, CL, Doublier, MP Australian Journal of Earth Sciences 61, 143–157 https://doi.org/10.1080/08120099.2013.812579
2014	On shearing, magmatism and regional deformation in Neoarchean granite-greenstone systems: Insights from the Yilgarn Craton	Zibra, I, Gessner, K, Smithies, RH, Peternell, M Journal of Structural Geology 67, 253–267 https://doi.org/10.1016/j.jsg.2013.11.010
2013	Lu–Hf isotopic memory of plume–lithosphere interaction in the source of layered mafic intrusions, Windimurra Igneous Complex, Yilgarn Craton, Australia	Nebel, O, Arculus, R, Ivanic, TJ, Nebel-Jacobsen, YJ Earth and Planetary Science Letters 380, 151–161 http://dx.doi.org/10.1016/j.epsl.2013.08.019
2013	Upper Zone of the Archean Windimurra layered mafic intrusion, Western Australia: insights into fractional crystallisation in a large magma chamber	Nebel, O, Arculus, RJ, Ivanic, TJ, Rapp, R, Wills, KJA Journal of Mineralogy and Geochemistry, 191, 83–107 https://doi.org/10.1127/0077-7757/2013/0249
2013	Long-lived, autochthonous development of the Archean Murchison Domain, and implications for Yilgarn Craton tectonics	Van Kranendonk, MJ, Ivanic, TJ, Wingate, MTD, Kirkland, CL, Wyche, S Precambrian Research 229, 49–92 https://doi.org/10.1016/j.precamres.2012.08.009
2012	Zircon Lu–Hf isotopes and granite geochemistry of the Murchison Domain of the Yilgarn Craton: evidence for reworking of Eoarchean crust during Meso-Neoarchean plume-driven magmatism	Ivanic TJ, Van Kranendonk, MJ, Kirkland, CL, Wyche, S, Wingate, MTD, Belousova, EA Lithos 148 112–127 https://doi.org/10.1016/j.lithos.2012.06.006
2012	Isotopic constraints on stratigraphy in the central and eastern Yilgarn Craton, Western Australia	Wyche, S, Kirkland, CL, Riganti, A, Pawley, MJ Australian Journal of Earth Sciences, 59, 657–670 https://doi.org/10.1080/08120099.2012.697677
2012	Syndeformational granite crystallisation along the Mount Magnet greenstone belt, Yilgarn Craton: evidence of large-scale magma-driven strain localisation during Neoarchean time	Zibra, I Australian Journal of Earth Sciences, v. 59, no. 5, p. 793–806, https://doi.org/10.1080/08120099.2012.684887
2010	Age and significance of voluminous mafic–ultramafic magmatic events in the Murchison Domain, Yilgarn Craton	Ivanic, TJ, Wingate, MTD, Kirkland, CL, Van Kranendonk, MJ, Wyche, S Australian Journal of Earth Sciences 57, 597–614 https://doi.org/10.1080/08120099.2010.494765
2007	Evaluating the provenance of Archean sedimentary rocks of the Diemals Formation (central Yilgarn Craton) using whole-rock chemistry and precise U – Pb zircon chronology	Morris, PA, Riganti, A, Chen, SF Australian Journal of Earth Sciences 54, 1123–1136 https://doi.org/10.1080/08120090701615758
2005	Occurrence of komatiites in the Sandstone greenstone belt, north-central Yilgarn Craton	Chen, SF, Morris, PA, Piranjo, F Australian Journal of Earth Sciences 52, 959–963 https://doi.org/10.1080/08120090500304240
2004	Kinematic nature and origin of regional-scale ductile shear zones in the central Yilgarn Craton, Western Australia	Chen, SF, Libby, JW, Wyche, S, Riganti, A Precambrian Research 107, 249–266 https://doi.org/10.1016/j.tecto.2004.08.001
2004	4350–3130 Ma detrital zircons in the Southern Cross Granite-Greenstone Terrane, Western Australia: Implications for the early evolution of the Yilgarn Craton	Wyche, S, Nelson, DR, Riganti, A Australian Journal of Earth Sciences, 51, 31–45 https://doi.org/10.1046/j.1400-0952.2003.01042.x.001
2003	Lithostratigraphy and tectonic evolution of contrasting greenstone successions in the central Yilgarn Craton, Western Australia	Chen, SF, Riganti, A, Wyche, S, Greenfield, JE, Nelson, DR Precambrian Research 127, 249–266 https://doi.org/10.1016/S0301-9268(03)00190-6
2001	Geometry and kinematics of large arcuate structures formed by impingement of rigid granitoids into greenstone belts during progressive shortening	Chen, SF, Libby, JW, Greenfield, JE, Wyche, S, Riganti, A Geology 29, 283–286 https://doi.org/10.1130/0091-7613(2001)029<0283:GAKOLA>2.0.CO;2
2001	Transpression and restraining jogs in the northeastern Yilgarn craton, Western Australia	Chen, SF, Witt, WK, Liu, S Precambrian Research 106, 309–328 https://doi.org/10.1016/S0301-9268(00)00138-8
1999	The Archaean Ravensthorpe Terrane, Western Australia: synvolcanic Cu–Au mineralization in a deformed island arc complex	Witt, WK Precambrian Research 96, 143–181 https://doi.org/10.1016/S0301-9268(98)00122-3

Acknowledgements

Much of this work is supported by the Western Australian Government Exploration Incentive Scheme.

Contact

For more information contact:

geological.survey@dmirs.wa.gov.au