Western Yilgarn

The Western Yilgarn project team continues to carry out geoscientific investigations including seamless detailed mapping (yielding map tiles at 1:100 000 scale), to advance our understanding of Archean granite–greenstone terrains, and to interpret their tectonic evolution and prospectivity.
Outline of the western Yilgarn project area showing published 1:100 000 Geological Series map sheets and digital updates
Outline of the western Yilgarn project area showing published 1:100 000 Geological Series map sheets and digital updates

The Youanmi Terrane is the dominant focus of the western Yilgarn project. The project area includes terrane boundaries with the Eastern Goldfields Superterrane to the east, and the Narryer and South West Terranes to the northwest and southwest, respectively. 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 over 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, with regularly updated digital layers concentrating on enhancing and improving earlier maps in critical, problematic or less well-studied areas. The study area is covered by recent aeromagnetic and radiometric surveys at 400 m line spacing, 2.5 km spaced gravity, and Landsat TM and DEM-derived imagery, as well as crustal-scale geophysical data 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 geochronological data, whole-rock and mineral isotope geochemistry, and whole-rock lithogeochemistry, these data help define the tectonic, depositional and mineralization history of the western part of the Yilgarn Craton.

GSWA publications can be accessed through the DMIRS eBookshop or from the lists below. The Youanmi 2020 Geological Information Series 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 Youanmi Terrane, western Yilgarn Craton

Stratigraphic framework for the northern Youanmi Terrane
Stratigraphic framework for the northern Youanmi Terrane showing mineralization events (right column), zircon ages (left column) and volcanic vs plutonic vs detrital age spectra (central column)

The largest component of the western Yilgarn Craton is the Youanmi Terrane, an extensive Archean granite–greenstone terrain that contains 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. At 300 000 km2 (~800 × 400 km) in area, the Youanmi Terrane is the largest of the tectonostratigraphic terranes that together form the Yilgarn Craton, and it has a long and complex geological history. An understanding of the tectonic evolution of the region, including its structure and stratigraphy, is essential to understanding the controls on formation and distribution of mineralization. Youanmi Terrane volcano-sedimentary greenstones were deposited between 2.99 and 2.70 Ga, in four main stages:

  1. 2.99–2.91 Ga, e.g. Madoonga, Gossan Valley, Chester and Honman Formations, Annabelle Volcanics
  2. 2.82–2.80 Ga Norie Group
  3. 2.80–2.74 Ga Polelle Group
  4. 2.74–2.71 Ga Glen Group and Marda Complex.

The Norie, Polelle and Glen Groups together form the Murchison Supergroup. Multiple mafic suites intruded the terrain during the Proterozoic, forming dyke swarms and sills.

Geoscientific investigations have identified hydrous gabbroic rocks, boninites and sanukitoids across the terrane, indicating that subduction-like processes played an important role in the post-2.82 Ga history of the western Yilgarn Craton. This 2.82 to 2.73 Ga period of voluminous mafic–ultramafic magmatism (the Annean Supersuite) also involved high degrees of mantle melting and intrusion of the Meeline Suite, which is attributed to mantle plume activity around 2.81 Ga, and resulted in extensive vanadium mineralization. Vertical tectonic doming at 2.75 Ga was followed by the onset of horizontal shortening and orogenesis from 2.73 Ga, accompanied by syntectonic granitic batholith intrusions of the Austin Downs Supersuite. Felsic plutonic rocks intruded during each of these time periods, and were followed by voluminous granitic plutonism from 2.7 to 2.6 Ga, which led to cratonization. Volcano-sedimentary formations were deposited at this time on a regionally extensive unconformity, resulting in the Ryansville and Diemals Formations. The main period of gold mineralization is dated at 2.66–2.63 Ga.

Much of the geoscientific work conducted so far in the Youanmi Terrane has concentrated on its post-2.82 Ga greenstone sequences. However, there is a large gap in the understanding of the crustal evolution of the proto-Yilgarn Craton and its architecture during the Mesoarchean from 3.1 to 2.9 Ga — also a period of significant base metal mineralization. Most rocks of this age within the Yilgarn Craton are in less well-known portions of the Youanmi Terrane, typically where data density is low. At present, the relationship between the Youanmi Terrane and both the Narryer and South West Terranes is unclear and will be a future focus of this project.

Thus, the main objective of the Western Yilgarn project is not only to expand the understanding of Neoarchean rocks but also to add a new level of knowledge to the extensive Mesoarchean history of the Youanmi Terrane. This will offer a wider appreciation of the configuration of the protocraton onto which the voluminous Norie, Polelle and Glen Groups were deposited, and through which the giant layered intrusions at 2.8 Ga were channelled. An expanded temporal framework and the documentation of new magmatic suites will allow for an improved context for mineral exploration within the Youanmi Terrane — in particular base metal, Ni, Fe and Au mineral systems.

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

For a full list of maps please follow the link

Further publications

Additional publications

Year

Title

Details

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

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

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

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

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

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

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

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