Product catalogue
Petrology, age, and rift origin of ultramafic lamprophyres (aillikites) at Mount Webb, a new alkaline province in central Australia
<div>Diamond exploration over the past decade has led to the discovery of a new province of kimberlitic pipes (the Webb Province) in the Gibson Desert of central Australia. The Webb pipes comprise sparse macrocrystic olivine set in a groundmass of olivine, phlogopite, perovskite, spinel, clinopyroxene, titanian-andradite and carbonate. The pipes resemble ultramafic lamprophyres (notably aillikites) in their mineralogy, major and minor oxide chemistry, and initial 87Sr/ 86Sr and <em>ε</em>Nd-<em>ε</em>Hf isotopic compositions. Ion probe U-Pb geochronology on perovskite (806 ± 22 Ma) indicates the eruption of the pipes was co-eval with plume-related magmatism within central Australia (Willouran-Gairdner Volcanic Event) associated with the opening of the Centralian Superbasin and Rodinia supercontinent break-up. The equilibration pressure and temperature of mantle-derived garnet and chromian (Cr) diopside xenocrysts range between 17 and 40 kbar and 750–1320°C and define a paleo-lithospheric thickness of 140 ± 10 km. Chemical variations of xenocrysts define litho-chemical horizons within the shallow, middle, and deep sub-continental lithospheric mantle (SCLM). The shallow SCLM (50–70 km), which includes garnet-spinel and spinel lherzolite, contains Cr diopside with weakly refertilized rare earth element compositions and unenriched compositions. The mid-lithosphere (70–85 km) has lower modal abundances of Cr diopside. This layer corresponds to a seismic mid-lithosphere discontinuity interpreted as pargasite-bearing lherzolite. The deep SCLM (>90 km) comprises refertilized garnet lherzolite that was metasomatized by a silicate-carbonatite melt.</div><div><br></div><div>Geoscience Australia’s Exploring for the Future program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to net zero emissions, strong, sustainable resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government.</div><div><br></div><div><strong>Citation:</strong></div><div>Sudholz, Z. J., et al. (2023). Petrology, age, and rift origin of ultramafic lamprophyres (aillikites) at Mount Webb, a new alkaline province in Central Australia. <i>Geochemistry, Geophysics, Geosystems</i>, 24, e2023GC011120.</div><div> https://doi.org/10.1029/2023GC011120</div>
Simple
Identification info
- Date (Creation)
- 2023-03-02T07:00:00
- Date (Publication)
- 2023-10-19T01:02:31
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/147707
- Cited responsible party
-
Role Organisation / Individual Name Details Author Sudholz, Z.J.
External Contact Author Reddicliffe, T.H.
External Contact Author Jaques, A.L.
External Contact Author Yaxley, G.M.
External Contact Author Haynes, M.
Internal Contact Author Gorbatov, A.
Internal Contact Author Czarnota, K.
Internal Contact Author Frigo, C.
External Contact Author Maas, R.
External Contact Author Knowles, B.
External Contact Publisher Wiley Periodicals LLC
External Contact
- Name
-
Geochemistry, Geophysics, Geosystems
- Issue identification
-
Vol 24 Issue 10
- Purpose
-
Journal article submitted to Contributions to Mineralogy and Petrology detailing new single-grain geothermobarometry and paleogeotherm modelling applied to mantle-derived pyrope garnet and chromium diopside xenocrysts.
- Status
- Completed
- Point of contact
-
Role Organisation / Individual Name Details Resource provider Minerals, Energy and Groundwater Division
External Contact Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Haynes, M.
Internal Contact
- Spatial representation type
- Topic category
-
- Geoscientific information
Extent
))
- Maintenance and update frequency
- Not planned
Resource format
- Title
-
Product data repository: Various Formats
- Website
-
Data Store directory containing the digital product files
Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes
- Project
-
-
EFTF – Exploring for the Future
-
- Project
-
-
Lithospheric Geophysics
-
- Keywords
-
-
North Australia Craton
-
- Keywords
-
-
Diamond Exploration
-
- Keywords
-
-
Musgrave Province
-
- Keywords
-
-
Willouran-Gairdner Volcanic Event
-
- Keywords
-
-
Rodinia
-
- Keywords
-
-
Mundine Well
-
- Keywords
-
-
Webb
-
- Keywords
-
-
Arunta Inlier
-
- Keywords
-
-
Centralian Superbasin
-
- Keywords
-
-
Geothermobarometry
-
- Keywords
-
-
Xenoliths
-
- Keywords
-
-
Xenocrysts
-
- Keywords
-
-
Lithospheric Mantle
-
- Keywords
-
-
Lithospheric architecture
-
- Keywords
-
-
Mid-Lithospheric Discontinuities
-
- theme.ANZRC Fields of Research.rdf
-
-
Earth Sciences
-
Inorganic geochemistry
-
Igneous and metamorphic petrology
-
Geothermics and radiometrics
-
Earth system sciences
-
- Keywords
-
-
Published_External
-
Resource constraints
- Title
-
Creative Commons Attribution 4.0 International Licence
- Alternate title
-
CC-BY
- Edition
-
4.0
- Addressee
-
Role Organisation / Individual Name Details User Any
- Use constraints
- License
- Use constraints
- Other restrictions
- Other constraints
-
© 2023 The Authors
Resource constraints
- Title
-
Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
- Classification system
-
Australian Government Security Classification System
- Language
- English
- Character encoding
- UTF8
Distribution Information
- Distributor contact
-
Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
Voice facsimile
- OnLine resource
-
Link to Journal
Link to Journal
- Distribution format
-
Resource lineage
- Statement
-
<div>The petrology and geochemistry of kimberlites has been constrained through detailed petrography, whole-rock geochemical analysis, ground-mass and matrix geochemistry, and U-Pb perovskite geochronology.</div><div><br></div><div>whole-rock (WR) analysis by X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). All WR analyses were conducted at the ALS Geochemical Laboratory, Queensland. Major and minor oxides were measured by fusion WR XRF, and trace elements were measured by lithium borate fusion ICP-MS. Base metals were determined by 4-acid digestion and the LOI was determined by TGA furnace.</div><div><br></div><div>Major and minor oxides were measured quantitatively by wavelength dispersive spectroscopy on a JEOL JXA-8530F+ EPMA at the Centre for Advanced Microscopy, the Australian National University. The concentrations of 40 trace element isotopes (see Appendix A for list) in Cr diopside and pyrope garnet were measured by laser ablation ICP-MS using an Agilent Technologies 7700x quadrupole mass spectrometer coupled to a Coherent Scientific Compex Pro 110 (λ = 193 nm) laser ablation system at the Research School of Earth Sciences, the Australian National University.</div><div><br></div><div>U-Pb geochronology on groundmass perovskite was conducted on one representative kimberlite from Webb (14008-1023) using the SHRIMP-RG at the Research School of Earth Sciences, Australian National University.</div><div><br></div><div>The equilibration PT of mantle-derived Cr diopside were determined using the single-grain Cr-in-clinopyroxene geobarometer of Sudholz et al. (2021a) and enstatite-in-clinopyroxene single-grain geothermometer of Nimis and Taylor (2000) using the PTEXL_2022 spreadsheet (maintained by T. Stachel, University of Alberta). Temperature estimates for pyrope garnet were determined using the experimentally calibrated Ni-in-garnet geothermometer of Sudholz et al. (2021b), using an olivine Ni concentration of 3000 ppm and garnet Ni concentrations measured by LA-ICP-MS. The equilibration P of garnet were determined by referencing Ni-in-garnet T estimates to the Cr diopside geotherm. The source lithology of analysed pyrope garnet were determined using a modified version of the G-number classification scheme (Sudholz et al. 2022b; modified after Grütter et al. 2004). The Mg# of olivine (Mg#olv = Mg/ (Mg + Fe)) coexisting with garnet in peridotite were determined by inverting the garnet-olivine Fe-Mg exchange geothermometer of O’Neill and Wood (1979) to solve for Ni-in-garnet T. The paleogeotherm for the Webb was constructed in FITPLOT (Mather et al. 2011) using 123 Cr diopside PT estimates. A crustal thickness of 40 km was taken from the AuSREM Moho model. A mantle isentrope of 1330 ℃ was assumed for the paleogeotherm.</div>
Metadata constraints
- Title
-
Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
-
urn:uuid/fa053e42-ed31-4547-8840-51536d388a5c
- Title
-
GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
-
Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Haynes, M.
Internal Contact
Type of resource
- Resource scope
- Document
- Name
-
Journal Article / Conference Paper
Alternative metadata reference
- Title
-
Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/147707
- Date info (Creation)
- 2023-10-19T00:48:48
- Date info (Revision)
- 2023-10-19T00:48:48
Metadata standard
- Title
-
AU/NZS ISO 19115-1:2014
Metadata standard
- Title
-
ISO 19115-1:2014
Metadata standard
- Title
-
ISO 19115-3
- Title
-
Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
-
Version 2.0, September 2018
- Citation identifier
- http://pid.geoscience.gov.au/dataset/ga/122551