Heterogeneity in the SCLM Multiple mantle source components identified from 1590 Ma mafic intrusions, Gawler Craton Claire Wade 1,2 , Justin Payne 3 , Anthony Reid 1,2 , Karin Barovich 2 1 Geological Survey of South Australia 2 School of Physical Sciences, University of Adelaide 3 School of Natural and Built Environments, University of South Australia AGCC Adelaide, 2018
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Heterogeneity in the SCLM
Multiple mantle source components identified from 1590 Ma mafic intrusions, Gawler Craton
Claire Wade1,2, Justin Payne3, Anthony Reid1,2, Karin Barovich2
1Geological Survey of South Australia2 School of Physical Sciences, University of Adelaide3School of Natural and Built Environments, University of South Australia
AGCC Adelaide, 2018
SCLM in the Gawler Craton
• The SCLM at 1590 Ma is complex and heterogeneous
• At least four compositional groups can be observed
• Resulting from partial melting of a metasomatised SCLM
• Role of a metasomatised SCLM for Cu and Au mineralisation IOCG
Province
Central Gawler
Gold Province
Province
(1590 Ma)
(1590 Ma)
SCLM in the Gawler Craton
• Geochemical connection between SCLM and metals by association of juvenile isotopes with increasing Cu and Au abundance
• Mantle connection important
References: Johnson and McCulloch, 1995. Chem. Geol.,
121, 177-199; Budd and Skirrow, 2007. Eco. Geol., 102,
1541–1563; Skirrow et al. 2007. Eco. Geol., 102, 1441-1470.
εNd vs Cu at Olympic Dam
(Skirrow et al. 2007)
SCLM in the Gawler CratonConductivity
pathways within the
mantle and crust
revealed in new MT
data and inversions
which link the lower
crust with major
IOCG-U deposits.
Heinson et al. 2018. Sci. Rep., 8:10608
2D seismic showing
zones of reduced
reflectivity under all
the major mineral
deposits.
A
A’
WW: Wirda Well; OD Olympic Dam; VC: Vulcan
• Lithospheric mantle is hydrous and metasomatised
• A heterogeneous and enriched mantle existed at 1590 Ma
• Previous work have been isolated studies, often limited by restricted geographical extent or limited data sets
• No systematic approach
SCLM in the Gawler Craton
References: Wade et al., 2012. Precam. Res., 206–207, 17–35; Thiel and