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| | | | | | | | | | | | | | | | | | | | | | | | Department of Mines, Industry Regulation and Safety |
| | | | Geological Survey of Western Australia |
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| | | | PW Haines | | | | | Type | Basin | Lithology | sedimentary rocks | Parent unit | | Child units | No child units | Constituent lithostratigraphic units | | Affected by events | | Tectonic setting | |
| | | Summary | The Yandanooka Basin is a component of the northern Pinjarra Orogen. Rocks of this basin, principally the Yandanooka Group, unconformably overlie the upper Mesoproterozoic Mullingarra Gneiss and are unconformably overlain by the Perth Basin. The basin succession is mainly exposed in an inlier within the northern Perth Basin with scattered outcrops extending from 40 km north-northwest to 32 km south of Three Springs. The eastern tectonic limit is inferred to be the Darling Fault, although contact with the fault is not exposed. Most outcrops of the succession dips steeply eastward and the estimated exposed thickness is 10 km. The isolated outcrop of Wenmillia Formation adjacent to the Darling Fault 80 km north of outcrops of the Yandanooka Group is tentatively included in the Yandanooka Basin. The Yandanooka Group comprises mainly siliciclastic sedimentary rocks (siltstone, sandstone and conglomerate) and a significant part has a volcaniclastic and locally possibly tuffaceous component. The Wenmillia Formation contains basaltic flows. The age is poorly constrained between late Mesoproterozoic and Neoproterozoic, but a Neoproterozoic age is considered most likely. The basin succession contains minor copper occurrences and at the time of writing is being actively explored for titanium. | | | Distribution | Outcrop of the Yandanooka Basin is largely restricted to the eastern part of a poorly exposed inlier within the northern Perth Basin, with scattered outcrops of Yandanooka Group extending from 40 km north-northwest to 32 km south of Three Springs. The eastern limit, under cover, is inferred to be the Darling Fault and the western limit is defined by outcrops of the underlying Mullingarra Gneiss. The basin likely extends at least 35 km south of the most southerly outcrop based in seismic interpretation. An isolated outcrop of Wenmillia Formation adjacent to the Darling Fault about 80 km north of outcrops of the Yandanooka Group is tentatively included in the Yandanooka Basin. If correct, the basin extends at least that far north under cover of the Perth Basin. | | | Description | The rocks of the Yandanooka Basin are mostly siliciclastic, being dominated by siltstone with lesser sandstone and conglomerate, with common evidence of a volcaniclastic and locally possibly tuffaceous component (Playford et al., 1976; Glover, 1960). The volcaniclastic component includes common basaltic clasts. A discontinuous local limestone-bearing lens is described by Baker (1951) and Wilson (1951). The small outcrop of Wenmillia Formation is mostly siliciclastic, predominantly siltstone with interbedded basalts considered to be flows (Playford et al., 1976). Most of the basin succession was probably deposited in a marine depositional environment (Playford, et al., 1976). The basin is deformed, with outcrops mostly dipping steeply east, but is mostly unmetamorphosed. The main stratigraphic component, the Yandanooka Group, is estimated to have an exposed thickness of 10 km (Playford et al., 1976). The basin contains minor copper occurrences and an historic small copper mine (Campbell, 1910; Low, 1963; Playford et al., 1976) and at the time of writing is being actively explored for titanium. | | | | | | Geochronology | | | Yandanooka Basin | Maximum age | Minimum age | Age (Ma) | 1100 | 539 | Age | Mesoproterozoic | Neoproterozoic |
| No radiometric dating has been undertaken from rocks of the Yandanooka Basin and no fossils have been reported apart from the bed of 'algal limestone' in the Arrino Siltstone, reported by Wilson (1951). The Yandanooka Group unconformably overlies the Mullingarra Gneiss, which has a metamorphic age of 1058 ± 83 Ma based on SHRIMP dating of zircon overgrowths (Cobb, 2000; Cobb et al., 2001). The youngest detrital zircon in this metasedimentary gneiss is 1113 ± 26 Ma (Cobb, 2000; Cobb et al., 2001). These dates and their uncertainties allow a latest Mesoproterozoic maximum age for the beginning of basin deposition. However, considering the time required for uplift and erosion of the Mullingarra Gneiss before renewed subsidence and deposition, a Neoproterozoic age seems more likely. Sparse dropstones of potentially ice-rafted origin are reported from a well-laminated siltstone within the Mount Scratch Siltstone (Baxter and Lipple, 1985). These need re-evaluation, but if confirmed as glaciogenic, a Cryogenian (or less likely mid-Ediacaran) age could be inferred for the younger part of the group. The age and origin of the common basaltic clasts is unknown, but one possibility is that they are related to extrusive equivalents of the Northampton Dolerite, which extensively intrudes the nearby Northampton inlier and has been dated at 748 ± 8 Ma (Embleton and Schmidt, 1985). A minimum age of latest Neoproterozoic can be inferred by the lack of Phanerozoic fossils despite the likelihood of dominantly marine depositional environments. The basin succession was deformed and eroded before the local initiation of Perth Basin deposition in the late Paleozoic. The deformation was most likely associated with the Leeuwin Orogeny, loosely constrained to 780–515 Ma. Although this event is mainly recorded in the Leeuwin Inlier and nearby areas of the southern Pinjarra Orogen, a metamorphic date of 526 ± 12 Ma from basement gneiss in Wendy 1 (Markwitz et al., 2016), about 150 km north-northwest of outcropping Yandanooka Group and closer to outcropping Wenmillia Formation, suggests that this event extended to the northern Pinjarra Orogen. | | | | | | | Contact relationships | | | | Tectonic unit name | Unit code | Contact type | Contact relationship | | Y | fault | is juxtaposed to YA | | PH | angular unconformity | overlies YA | | PJMU | angular unconformity | underlies YA | | MO | fault | is juxtaposed to YA |
| | | | | | Minimum depth to basement (m) | –– | | Maximum depth to basement (m) | 10000 | |
| On its western side, the main exposure of Yandanooka Basin rocks unconformably overlie the Mullingarra Gneiss and to the east they are inferred to be tectonically juxtaposed against the Yilgarn Craton and Moora Basin at the Darling Fault. The Wenmillia Formation is in fault contact with the Yilgarn Craton, but the original stratigraphic top and base of that unit are not exposed. In both areas steeply dipping Yandanooka Basin rocks are unconformably overlain by flat lying Carboniferous–Permian Nangetty Formation of the Perth Basin. | | | Tectonic setting | The tectonic setting of the Yandanooka Basin is uncertain as the preserved extent is presumably only a fragment of the original depositional system. It is possible intracratonic or a continental margin basin, but this issue has not been well researched. The exposed parts of the basin have been tilted steeply, mostly towards the east by a post-depositional tectonic event, but before the initiation of the Perth Basin. This event was probably the Leeuwin Orogeny. | BookMark | | | | | Constituent lithostratigraphic units | | | Unit name | Unit code | Rank | GSWA status | | | Formation | Formal | | | Formation | Formal | Beaconsfield Conglomerate | | Formation | Formal | | | Formation | Formal | | | Formation | Formal | | | Formation | Formal | | | Group | Formal |
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| | | | | | References | Baker, GFU 1951, Precambrian geology of Yandanooka, Western Australia: The University of Western Australia, Perth, Western Australia, BSc. (Honours) thesis (unpublished), 86p. | Baxter, JL and Lipple, SL (compilers) 1985, Perenjori, Western Australia: Geological Survey of Western Australia, 1:250 000 Geological Series Explanatory Notes, 32p. View Reference | Campbell, WD 1910, The Irwin River Coalfield and the adjacent districts from Arrino to Northampton: Geological Survey of Western Australia, Bulletin 38, 100p. View Reference | Cobb, MM 2000, The age and origin of the Mullingarra Complex and its role in orogenic activity and assembly of East Gondwana: Curtin University of Technology, Perth, Western Australia, BSc Honours thesis (unpublished), 136p. | Cobb, MM, Cawood, PA, Kinny, PD and Fitzsimons, ICW 2001, SHRIMP U-Pb zircon ages from the Mullingarra Complex, Western Australia: Isotopic evidence for allochthonous blocks in the Pinjarra Orogen and implications for East Gondwana assembly, in 2001: A structural odyssey: Geological Society of Australia, Abstracts, p. 21–22. | Embleton, BJJ and Schmidt, PW 1985, Age and significance of magnetizations in dolerite dykes from the Northampton Block, Western Australia: Australian Journal of Earth Sciences, v. 32, no. 3, p. 279–286, doi:10.1080/08120098508729330. | Glover, JE 1960, A contribution to the petrology of the Yandanooka Group: Journal of the Royal Society of Western Australia, v. 43, p. 97–103. | Low, GH 1963, Copper deposits of Western Australia: Geological Survey of Western Australia, Mineral Resources Bulletin 8, 202p. View Reference | Markwitz, V, Kirkland, CL and Evans, NJ 2016, Early Cambrian metamorphic zircon in the northern Pinjarra Orogen: Implications for the structure of the Western Australian Craton margin: Lithosphere, v. 9, no. 1, p. 3–13. | Playford, PE, Cockbain, AE and Low, GH 1976, Geology of the Perth Basin, Western Australia: Geological Survey of Western Australia, Bulletin 124, 311p. View Reference | Wilson, AF 1951, Pre-Cambrian algal limestones: Geological Magazine, v. 88, no. 2, p. 149–150, doi:10.1017/S0016756800069120. |
| | | | Recommended reference for this publication | Haines, PW 2025, Yandanooka Basin (YA): Geological Survey of Western Australia, WA Geology Online, Explanatory Notes extract, viewed 06 August 2025. <www.dmp.wa.gov.au/ens> |
| | | This page was last modified on 10 April 2025. | | | | | 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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