Capricorn Orogen

The Capricorn Orogen project mapping teams have carried out geoscientific investigations including detailed mapping at the 1:100 000 scale, to advance our understanding of the Proterozoic Capricorn Orogen, including its tectonic evolution and prospectivity.

Basement rocks of the Gascoyne Province and the overlying sedimentary rocks of the Edmund and Collier Basins were first systematically mapped by the Geological Survey of Western Australia (GSWA) in the 1960s and 1970s. Products from this program included 1:250 000 scale maps and Explanatory Notes, and a number of early Reports. Systematic 1:100 000 scale field mapping from 1996 to 2017 has produced over 44 first and second edition printed maps, Explanatory Notes for all lithostratigraphic units and events, as well as numerous Reports and Records outlining the protracted tectonic history of this part of the Orogen. The province and basins are covered by recent aeromagnetic and radiometric data 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, and regional-scale passive seismic data. Together with abundant SHRIMP U–Pb zircon, monazite and xenotime geochronology, whole-rock and mineral isotope geochemistry, and whole-rock lithogeochemistry, these data help define the tectonic, depositional and mineralization history of the Orogen.

Links to GSWA’s and other publications are provided below. The Capricorn Orogen 2016 Geological Information Series package is the most up-to-date compilation for the project.

Tectonic evolution of the Capricorn Orogen

Simplified geological map of the Capricorn Orogen showing the distribution of major structures, mineral deposits and occurrences
Simplified geological map of the Capricorn Orogen showing the distribution of major structures, mineral deposits and occurrences

The Capricorn Orogen of Western Australia is a ~ 1000 km long, 500 km wide region of variably deformed Archean to Proterozoic rocks located between the Pilbara and Yilgarn Cratons. The orogen records the punctuated Paleoproterozoic assembly of these two cratons, as well as an exotic Archean to Paleoproterozoic continental fragment — the Glenburgh Terrane of the Gascoyne Province — to form the West Australian Craton, as well as over one billion years of subsequent intracratonic reworking and reactivation. The orogen includes the deformed margins of the Pilbara and Yilgarn Cratons and associated continental margin rocks of the Fortescue, Hamersley, Turee Creek and Shingle Creek Groups; medium- to high-grade meta-igneous and metasedimentary rocks of the Gascoyne Province; and various low-grade (meta)sedimentary rocks including the Wyloo, Bresnahan, Mount Minnie, Padbury, Bryah, Yerrida, Earaheedy, Edmund and Collier Groups.

Collision between the Pilbara Craton and the Glenburgh Terrane occurred during the 2215–2145 Ma Ophthalmia Orogeny while assembly of the West Australian Craton was completed during the 2005–1950 Ma Glenburgh Orogeny when the combined Pilbara–Glenburgh block collided with the Yilgarn Craton. The orogen was subject to repeated reworking and reactivation during the 1817–1772 Ma Capricorn Orogeny, the 1680–1620 Ma Mangaroon Orogeny, the 1321–1171 Ma Mutherbukin Tectonic Event, the 1026–954 Ma Edmundian Orogeny, the 931–749 Ma Kuparr Tectonic Event, and the c. 570 Ma Mulka Tectonic Event.

Despite the widespread abundance of gold, base metal and rare earth element occurrences throughout the Orogen, the region has few working mines. However, over the past decade there have been significant discoveries such as the world-class Cu–Au–Ag DeGrussa deposit in the east. A recent deep crustal seismic reflection survey across the Orogen, as well as numerous other geophysical surveys, have led to a growing understanding of the relationship between the deep crustal architecture and the location and setting of the ore deposits. These studies have identified several discrete crustal blocks that are exposed at the surface, including the Pilbara and Yilgarn Cratons, and the Glenburgh Terrane, as well as several unexposed deep crustal terranes, including the Bandee and MacAdam Seismic Provinces. These discrete tectonic blocks are sutured along three major crustal structures — the Cardilya, Lyons River and Baring Downs Faults — which most likely represent collisional suture zones associated with the assembly of the West Australian Craton. The location and orientation of these collision-related structures appear to have fundamentally controlled all subsequent intraplate reworking events, including the style and orientation of deformation, as well as the location of magmatism, sedimentation and mineralization.

The Gascoyne Province

The Gascoyne Province forms the medium- to high-grade metamorphic core of the orogen. The oldest component is the Glenburgh Terrane, interpreted to be an exotic microcontinent. The terrane comprises heterogeneous granitic gneisses of the 2555–2430 Ma Halfway Gneiss and voluminous intermediate to granitic rocks of the 2005–1975 Ma Dalgaringa Supersuite, which forms an extensive granite batholith along the southern margin of the terrane. The Dalgaringa Supersuite magmatic rocks are interpreted to have been generated in a continental margin arc setting along the (present-day) southern margin of the terrane during the final amalgamation of the West Australian Craton. Following the assembly of the West Australian Craton, the province was structurally and thermally reworked during at least five punctuated intraplate orogenic events over a period of more than one billion years. Many of the events were accompanied by the intrusion of voluminous syntectonic felsic magmatic rocks. Granitic rocks associated with the Capricorn, Mangaroon and Edmundian Orogenies show similar calc-alkaline geochemical signatures and were generated and emplaced entirely within an intraplate tectonic setting. The protracted crustal reworking history of the Province has led to a highly differentiated orogenic crust, whereby the shallow portion has been enriched in high-heat producing elements such as U, Th and K, resulting in warmer crustal geotherms that may have weakened the lithosphere, making the orogen more susceptible to intraplate reworking.

Well-exposed granitic rocks of the Moorarie and Durlacher Supersuites in the central part of the Gascoyne Province
Well-exposed granitic rocks of the Moorarie and Durlacher Supersuites in the central part of the Gascoyne Province

The Edmund and Collier Basins

The 1679–1067 Ma Edmund and Collier Basins are the youngest depositional elements of the Capricorn Orogen and contain 4–12 km of siliciclastic, carbonate and minor volcaniclastic sedimentary rocks deposited in a variety of fluvial to deep-marine environments. The rocks have been divided into six informal depositional packages, each defined by basal unconformities or major marine flooding surfaces and are the result of differential fault movements or fluctuations in sea level. Voluminous mafic sills were intruded into the basins at various times, locally inflating the stratigraphic thickness by up to 60%. The Edmund Group was intruded by the Waldburg and Narimbunna Dolerites, and the Edmund and Collier Groups were both intruded by the c. 1070 Ma Kulkatharra Dolerite.

The Edmund Basin has a half-graben architecture formed by the normal reactivation of older basement faults and sutures during the latter part of the Mangaroon Orogeny. Regional-scale extension during this time period has been calculated at ~ 7–8%. Paleocurrent directions and detrital zircon studies show that sediment supply was largely from the north. The Edmund Group sedimentary rocks were deformed during the Mutherbukin Tectonic Event prior to the deposition of the overlying Collier Group. The architecture of the Collier Basin is still poorly known, but the age and isotopic composition of detrital zircons indicate that the sediments were sourced directly from the underlying rocks of the Edmund Basin. Both groups were deformed during the Edmundian Orogeny, the Kuparr Event, and the Mulka Tectonic Event. Total regional-scale shortening during all postdepositional orogenic events is calculated at ~ 21%.

The Edmund and Collier Basins contain a wide range of mineral occurrences including supergene manganese and lead, minor gold and phosphate, as well as Western Australia's largest stratabound Pb–Ag–Cu–Au deposit at Abra. Many of these deposits are associated with major crustal-scale faults that have been reactivated multiple times.

An exposed unconformable contact of Kiangi Creek Formation conglomerate (Edmund Group) with saprolitic granitic rocks of the Moorarie Supersuite
An exposed unconformable contact of Kiangi Creek Formation conglomerate (Edmund Group) with saprolitic granitic rocks of the Moorarie Supersuite
Well-developed slickenlines indicating sinistral transpressive movement on a slickenside fault intersecting black chert of the Devil Creek Formation (Edmund Group)
Well-developed slickenlines indicating sinistral transpressive movement on a slickenside fault intersecting black chert of the Devil Creek Formation (Edmund Group)

Explanatory Notes

Detailed descriptions of all lithological units and tectonic events in the Capricorn orogeny can be accessed through the Explanatory Notes System (ENS).

Reports

Records

Maps

Further publications

Further articles and posters are available on the Department’s eBookshop.

2018

Extensional episodes in the Paleoproterozoic Capricorn Orogen, Western Australia, revealed by petrogenesis and geochronology of mafic–ultramafic rocks

Olierook, HKH, Sheppard, S, Johnson, SP, Occhipinti, SA, Reddy, SM, Clark, C, Fletcher, IR, Rasmussen, B, Zi, Z-W, Pirajno, F, LaFlamme, C, Do, T, Ware, B, Blandthorn, E, Lindsay, M, Lu, Y-J, Crossley, RJ and Erikson, TM

Precambrian Research, 306, 22–40 doi:10.1016/j.precamres.2017.12.015

2017 The tectonics and mineral systems of Proterozoic Western Australia: Relationships with supercontinents and global secular change

Aitken, ARA, Occhipinti, SA, Lindsay, MD, Joly, A, Howard, HM, Johnson, SP, Hollis, JA, Spaggiari, CV, Tyler, IM, McCuaig, TC and Dentith, MC

Geoscience Frontiers, 9, 295–316 doi:10.1016/j.gsf.2017.05.008

2017 Paleoproterozoic basin development on the northern Yilgarn Craton, Western Australia

Occhipinti, SA, Hocking, RM, Lindsay, MD, Aitken, ARA, Copp, I, Jones, J, Sheppard, S, Pirajno, F and Metelka, V

Precambrian Research, 300, 121–140 doi:10.1016/j.precamres.2017.08.003

2017 Monazite trumps zircon: applying SHRIMP U–Pb geochronology to systematically evaluate emplacement ages of leucocratic, low-temperature granites in a complex Precambrian orogen

Piechocka, AM., Gregory, CJ., Zi, J–W, Sheppard, S, Wingate, MTD and Rasmussen, B

Contributions to Mineralogy and Petrology, 172, 63p doi:10.1007/s00410-017-1386-5

2017 Using In Situ SHRIMP U–Pb Monazite and Xenotime Geochronology to Determine the Age of Orogenic Gold Mineralization: An Example from the Paulsens Mine, Southern Pilbara Craton

Fielding, IOH, Johnson, SP, Zi, J–W, Rasmussen, B, Muhling, JR., Dunkley, DJ, Sheppard, S, Wingate, MTD and Rogers, JR

Economic Geology, 112, 1205–1230 doi:10.5382/econgeo.2017.4507

2017 An isotopic perspective on growth and differentiation of Proterozoic orogenic crust: From subduction magmatism to cratonization

Johnson, SP, Korhonen, FJ, Kirkland, CL, Cliff, JB, Belousova, EA and Sheppard, S

Lithos, 268, 76–86 doi:10.1016/j.lithos.2016.11.003

2017

Radiogenic heating and craton-margin plate stresses as drivers for intraplate orogeny

Korhonen, FJ, Johnson, SP, Wingate, MTD, Kirkland, CL, Fletcher, IR, Dunkley, DJ, Roberts, MP, Sheppard, S, Muhling, JR and Rasmussen, B

Journal of Metamorphic Geology, 35, 631–661 doi:10.1111/jmg.12249

2017

The evolution of a Precambrian arc-related granulite facies gold deposit: Evidence from the Glenburgh deposit, Western Australia

Roche, LK, Korhonen, FJ, Johnson, SP, Wingate, MTD, Hancock, EA, Dunkley, DJ, Zi, Z–W, Rasmussen, B., Muhling, JR, Occhipinti, SA, Dunbar, M and Goldsworthy, J

Precambrian Research, 290, 63–85 doi:10.1016/j.precamres.2016.12.007

2016 A new Paleoproterozoic tectonic history of the eastern Capricorn Orogen, Western Australia, revealed by U–Pb zircon dating of micro-tuffs

Sheppard, S, Fletcher, IR, Rasmussen, B, Zi, J–W, Muhling, JR, Occhipinti, SA, Wingate, MTD and Johnson, SP

Precambrian Research, 286, 1–19 doi:10.1016/j.precamres.2016.09.026

2015 The role of radiogenic heat in prolonged intraplate reworking: The Capricorn Orogen explained?

Korhonen, FJ and Johnson, SP

Earth and Planetary Science Letters, 428, 22–32 doi:10.1016/j.epsl.2015.06.039

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

Zi, J–W, Rasmussen, B, Muhling, JR, Fletcher, IR, Thorne, AM, Johnson, SP, Cutten, HN, Dunkley, DJ and Korhonen, FJ

Precambrian Research, 260, 91–112 doi:10.1016/j.precamres.2015.01.010

2014 The Gifford Creek Ferrocarbonatite Complex, Gascoyne Province, Western Australia: Associated fenitic alteration and a putative link with the ~1075 Ma Warakurna LIP

Pirajno, F, González-Álvarez, I, Chen, W, Kyser, KT, Simonetti, A, Leduc, E and leGras, M

Lithos, 202–203, 100–119 doi:10.1016/j.lithos.2014.05.012

2013

Crustal architecture of the Capricorn Orogen, Western Australia from deep crustal reflection data

Johnson, SP, Thorne, AM, Korsch, RJ, Tyler, IM, Kennett, BLN, Cutten, HN, Blay, O, Blewett, RS, Goodwin, J, Holzschuh, J, Salmon, M, Dentith, MC, Aitken, ARA, Joly, A, Reading, A, Boren, G, Ross, J Costelloe, RD and Fomin, T

Australian Journal of Earth Sciences, 60, 681–705 doi:10.1080/08120099.2013.826735

2012 Seismic structure of the crust and uppermost mantle of the Capricorn and Paterson orogens and adjacent cratons, Western Australia, from passive seismic transects

Reading, AM, Tkalcic, H, Kennett, BLN, Johnson, SP and Sheppard, S

Precambrian Research, v. 196–197, 295–308 doi:10.1016/j.precamres.2011.07.001

2011 Two collisions, two sutures: Punctuated pre-1950 Ma assembly of the West Australian Craton during the Ophthalmian and Glenburgh Orogenies

Johnson, SP, Sheppard, S, Rasmussen, B, Wingate, MTD, Kirkland, CL, Muhling, JR, Fletcher, IR and Belousova, EA

Precambrian Research, 189, 239–262 doi:10.1016/j.precamres.2011.07.011

2010 Tectonic setting and regional implications of ca 2.2 Ga mafic magmatism in the southern Hamersley Province, Western Australia

Martin, DMcB and Morris, PA

Australian Journal of Earth Sciences, 57, 911–931 doi:10.1080/08120099.2010.510172

2010

The Magellan Pb deposit, Western Australia: a new category within the class of supergene non-sulphide mineral systems

Pirajno, F, Burlow, R and Huston, DL

Ore Geology Reviews, 37, 101–113 doi:10.1016/j.oregeorev.2010.01.001

2009 Identifying the lithospheric structure of a Precambrian orogen using magnetotellurics: the Capricorn Orogen, Western Australia

Selway, K, Sheppard, S, Thorne, AM, Johnson, SP and Groenewald, PB

Precambrian Research, 168, 185–196 doi:10.1016/j.precamres.2008.09.010

2009 A review of the geology and geodynamic evolution of the Palaeoproterozoic Earaheedy Basin, Western Australia

Pirajno, F, Hocking, RM, Reddy, S and Jones AJ

Earth-Science Reviews, 94, 39–77 doi:10.1016/j.earscirev.2009.03.003

2009 Chemical fingerprinting of multiple large-scale magmatic events in the Mesoproterozoic Bangemall Supergroup, Western Australia

Morris, PA and Pirajno, F

Australian Journal of Earth Sciences, 56, 985–1001 doi:10.1080/08120090903112091

2008 Provenance history of the Bangemall Supergroup and implications for the Mesoproterozoic paleogeography of the West Australian Craton

Martin, DMcB, Sircombe, KN, Thorne, AM, Cawood, PA and Nemchin AA

Precambrian Research, 166, 93–110 doi:10.1016/j.precamres.2007.07.027

2008 Role of geochronology in our present-day understanding of the Proterozoic: an Australian perspective

Sheppard, S, Rasmussen, B, Bodorkos, S and Tyler, IM

Australian Journal of Earth Sciences, 55, 795–819 doi:10.1080/08120090802097393

2007 Grenvillian-aged orogenesis in the Palaeoproterozoic Gascoyne Complex, Western Australia: 1030–950 Ma reworking of the Proterozoic Capricorn Orogen

Sheppard, S, Rasmussen, B, Muhling, JR, Farrell, TR and Fletcher, IR

Journal of Metamorphic Geology, 25, 477–494 doi:10.1111/j.1525-1314.2007.00708.x

2005 Intracontinental reworking in the Capricorn Orogen, Western Australia: the 1680–1620 Ma Mangaroon Orogeny

Sheppard, S, Occhipinti, SA and Nelson, DR

Australian Journal of Earth Sciences, 52, 443–460 doi:10.1080/08120090500134589

2004 Assembling and reactivating the Proterozoic Capricorn Orogen: lithotectonic elements, orogenies, and significance

Cawood, PA and Tyler, IM

Precambrian Research, 128, 201–218 doi:10.1016/j.precamres.2003.09.001

2004

A 2005–1970 Ma Andean-type batholith in the southern Gascoyne Complex, Western Australia

Sheppard, S, Occhipinti, SA and Tyler, IM

Precambrian Research, 128, 257–277 doi:10.1016/j.precamres.2003.09.003

2004 Geology and tectonic evolution of Palaeoproterozoic basins of the eastern Capricorn Orogen, Western Australia

Pirajno, F, Jones, JA, Hocking, RM and Halilovic, J

Precambrian Research, 128, 315–342 doi:10.1016/j.precamres.2003.09.006

2004 Provenance of the Earaheedy Basin: implications for assembly of the Western Australian Craton

Halilovic, J, Cawood, PA, Jones, JA, Pirajno, F and Nemchin, AA

Precambrian Research, 128, 315–342 doi:10.1016/j.precamres.2003.09.007

2004 Tectonic setting and basin evolution of the Bangemall Supergroup in the northwestern Capricorn Orogen

Martin, DMcB and Thorne, AM

Precambrian Research, 128, 385–409 doi:10.1016/j.precamres.2003.09.009

2004 Metallogeny in the Capricorn Orogen, Western Australia, the result of multiple ore-forming processes

Pirajno, F

Precambrian Research, 128, 411–439 doi:10.1016/j.precamres.2003.09.010

2004 Oceanic plateau accretion onto the northwestern margin of the Yilgarn Craton, Western Australia: implications for a mantle plume event at ca. 2.0 Ga

Pirajno, F

Journal of Geodynamics, 37, 205–231 doi:10.1016/j.jog.2004.02.003

2004 Warakurna large igneous province: A new Mesoproterozoic large igneous province in west-central Australia

Wingate, MTD, Pirajno, F and Morris, PA

Geology, 32(2), 105–108 doi:10.1130/G20171.1

2003 The relationship between tectonism and composition of granitoid magmas, Yarlarweelor Gneiss Complex, Western Australia

Sheppard, S, Occhipinti, SA and Tyler IM

Lithos, 66, 133–154 doi:10.1016/S0024-4937(02)00216-5

2002 Chert in the Palaeoproterozoic Bartle Member, Killara Formation, Yerrida Basin, Western Australia: a rift-related playa lake and thermal spring environment?

Pirajno, F and Grey, K

Precambrian Research, 113, 169–192 doi:10.1016/S0301-9268(01)00196-6

2000 Three Palaeoproterozoic basins—Yerrida, Bryah and Padbury—Capricorn Orogen, Western Australia

Pirajno, F and Occhipinti, SA

Australian Journal of Earth Sciences, 47, 675–688 doi:10.1046/j.1440-0952.2000.00800.x

1999 Pseudomorphs after evaporitic minerals interbedded with 2.2 Ga stromatolites of the Yerrida basin, Western Australia: Origin and significance

Tabakh, ME, Grey, K, Pirajno, F and Schrieber, BC

Geology, 27(10), 871–874 doi:10.1130/0091-7613(1999)027<0871:PAEMIW>2.3.CO;2

1998 Syntectonic granite in the southern margin of the Palaeoproterozoic Capricorn Orogen, Western Australia

Occhipinti, SA, Sheppard, S, Nelson, DR, Myers, JS and Tyler, IM

Australian Journal of Earth Sciences, 45, 509–512 doi:10.1080/08120099808728408

1998 Geology and tectonic evolution of the Palaeoproterozoic Bryah, Padbury and Yerrida Basins (formerly Glengarry Basin), Western Australia: implications for the history of the south-central Capricorn Orogen

Pirajno, F, Occhipinti, SA and Swager, CP

Precambrian Research, 90, 119–140 doi:10.1016/S0301-9268(98)00045-X

1998 Structural-metamorphic evolution of the Palaeoproterozoic Bryah and Padbury Groups during the Capricorn orogeny, Western Australia

Occhipinti, SA, Swager, CP and Pirajno, F

Precambrian Research, 90, 141–158 doi:10.1016/S0301-9268(98)00046-1

1990 The northern margin of the Capricorn Orogen, Western Australia—an example of an Early Proterozoic collision zone

Tyler, IM and Thorne AM

Journal of Structural Geology, 12, 685–701 doi:10.1016/0191-8141(90)90082-A

 

 

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