Plundering Carlow Castle: First Look at a Unique Mesoarchean-Hosted Cu-Co-Au Deposit

2019 ◽  
Vol 114 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
David C.M. Fox ◽  
Samuel C. Spinks ◽  
Mark A. Pearce ◽  
Milo Barham ◽  
Margaux Le Vaillant ◽  
...  
Keyword(s):  
Shear Zone ◽  
Western Australia ◽  
Relative Stability ◽  
Ore Deposits ◽  
Sedimentary Sequence ◽  
Scientific Analysis ◽  
Ore Minerals ◽  
Stratigraphic Position ◽  
Pilbara Craton ◽  
Proterozoic Age

Abstract Economically significant and geologically complex veined Cu-Co-Au mineralization was recently discovered at Carlow Castle in the Pilbara region of northwestern Western Australia. The inferred resource estimate for Carlow Castle as of March 2019 is 7.7 million tonnes (Mt) at 1.06 g/t Au, 0.51% Cu, and 0.08% Co, making it one of Australia’s most significant known Cu-Co-Au deposits. Here we provide the first account and scientific analysis of Carlow Castle. This analysis suggests that it is a hydrothermal Cu-Co-Au deposit, with mineralization hosted in sulfide-rich quartz-carbonate veins. The ore is hosted in veins that occur within a pervasively chloritized shear zone through the regionally significant Regal thrust. At Carlow Castle the shear zone associated with this thrust occurs within the Ruth Well Formation, an Archean mafic volcano-sedimentary sequence. Within the mineralized veins the dominant ore minerals are pyrite (FeS2), chalcopyrite (CuFeS2), chalcocite (Cu2S), cobaltite (CoAsS), and electrum (Au,Ag). The genesis of the Carlow Castle deposit is still under investigation; however, the origin of the Cu-Co-Au mineralization is most likely related to the migration of metalliferous fluids along the Regal thrust. Based on Carlow Castle’s stratigraphic position within the Pilbara craton and the craton’s relative stability since the Archean, an Archean age of mineralization is most likely. The distinct Cu-Co-Au enrichment at Carlow Castle makes it unique among Archean ore deposits generally, as the majority of Cu-Co deposits are of maximum Proterozoic age. Therefore, understanding the genesis of the Carlow Castle deposit has important implications for understanding the unique processes through which Cu-Co-Au mineralization outside of basin-hosted ore deposits may be formed, particularly in Archean terranes.

3.43 billion-year-old stromatolite reef from the Pilbara Craton of Western Australia: Ecosystem-scale insights to early life on Earth

2007 ◽  
Vol 158 (3-4) ◽  
pp. 198-227 ◽  
Author(s):  
Abigail C. Allwood ◽  
Malcolm R. Walter ◽  
Ian W. Burch ◽  
Balz S. Kamber
Keyword(s):  
Western Australia ◽  
Early Life ◽  
Life On Earth ◽  
Pilbara Craton

UPb zircon geochronology of Archaean felsic units in the Marble Bar region, Pilbara Craton, Western Australia

1992 ◽  
Vol 56 (3-4) ◽  
pp. 169-189 ◽  
Author(s):  
R.I. Thorpe ◽  
A.H. Hickman ◽  
D.W. Davis ◽  
J.K. Mortensen ◽  
A.F. Trendall
Keyword(s):  
Western Australia ◽  
Zircon Geochronology ◽  
Pilbara Craton

Geochemistry of Paleoarchean Granites of the East Pilbara Terrane, Pilbara Craton, Western Australia

2019 ◽  
pp. 487-518 ◽  
Author(s):  
David C. Champion ◽  
Robert H. Smithies
Keyword(s):  
Western Australia ◽  
Pilbara Craton

Isotope and rare earth element evidence for a late archaean terrane boundary in the southeastern pilbara craton, western australia

1992 ◽  
Vol 54 (2-4) ◽  
pp. 211-229 ◽  
Author(s):  
I.M. Tyler ◽  
I.R. Fletcher ◽  
J.R. de Laeter ◽  
I.R. Williams ◽  
W.G. Libby
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Western Australia ◽  
Earth Element ◽  
Late Archaean ◽  
Pilbara Craton

scholarly journals Iron Ore Deposits and Future Properties of Iron Ore Products in Western Australia

1992 ◽  
Vol 78 (7) ◽  
pp. 960-968 ◽  
Author(s):  
Yukihiro HIDA ◽  
Nobuji NOSAKA
Keyword(s):  
Western Australia ◽  
Iron Ore ◽  
Ore Deposits ◽  
Iron Ore Deposits

Shear zone development and structurally-controlled skarn ore mineralization in the Rosas district, SW Sardinia.

2021 ◽  
Author(s):  
Matteo Luca Deidda ◽  
Antonio Attardi ◽  
Fabrizio Cocco ◽  
Dario Fancello ◽  
Antonio Funedda ◽  
...  
Keyword(s):  
Shear Zone ◽  
Large Scale ◽  
Ore Deposits ◽  
Axial Plane ◽  
Contact Metamorphism ◽  
Upper Ordovician ◽  
Fold And Thrust Belt ◽  
Ore Mineralization ◽  
Map Scale ◽  
Stratigraphic Succession

<p>The Rosas Shear Zone (RSZ) is a 1 km thick brittle-ductile shear zone that outcrops in the Variscan fold and thrust belt foreland of SW Sardinia, where several important ore deposits were mined in the last century. The RSZ lies in the footwall and strikes parallel to the NE-dipping regional thrust that separates the Variscan foreland from the nappe zone. Two thrusts that developed along the limbs of two km-scale overturned antiforms, with NE-dipping axial plane, bound the RSZ. The folds show a SW-facing direction and a well-developed axial plane cleavage, and affect a lower Cambrian-upper Ordovician stratigraphic succession mainly made, from bottom to top, by a sequence about 200 m thick of dolostones and massive limestone followed by 50 m of marly limestones overlain by about 150 m of sandstones, pelites and siltstones, finally unconformable capped by conglomerates and siltstones, ranging in thickness from a few to 200 m. Differently, within the RSZ the bedding is completely transposed along the cleavage and its internal structure is characterized by anastomosing thrusts that affect the stratigraphic succession defining map-scale slices mainly consisting of dolostones and limestones embedded into the siliciclastic formations. It is noteworthy the occurrence of a NE-dipping, up to 100 m thick gabbro-dyke that postdates the deformation phases and that can be related to the exhumation of the chain during late Carboniferous-Permian times.</p><p>In the whole area, contact metamorphic and metasomatic processes selectively affected the Cambrian carbonate tectonic slices, originating several skarn-type orebodies. Mineralized rocks display the mineralogical assemblages and textures of Fe-Cu-Zn skarns, with relicts of anhydrous calcic phases related to the prograde metamorphic stage (garnet, clinopyroxene, wollastonite), frequently enclosed in a mass of hydrous silicates (actinolitic amphibole, epidote) and magnetite related to the retrograde metasomatic stage, in turn followed by chlorite, sulfides, quartz and calcite associated to the hydrothermal stage. Metasomatic reactions also involved mafic rocks, producing a mineral association marked by clinopyroxene, amphibole, epidote, prehnite and Ba-rich K-feldspar. Sulfide ores are made of prevailing sphalerite, chalcopyrite and galena, with abundant pyrite and pyrrhotite and minor tetrahedrite and Ag-sulfosalts. Garnets are andraditic/grossularitic, distinctly zoned and optically anisotropic. Field surveys pointed out the tight structural controls on skarn and ore formation. On a local scale, the gabbro emplacement along high- to low-angle NNW-SSE structures bordering the carbonate tectonic slices accentuate the effects of contact metamorphism, and metric to decametric mineralogical zonation (garnet→pyroxene→wollastonite) are recognized. On a larger scale, extensive hydrothermal fluid circulations involved the structures of the RSZ. Infilling of metasomatic fluids in carbonate tectonic slices is fault-controlled and aided by the increase in permeability due to the alteration of prograde silicates. The causative intrusion related to skarn ores belongs to the early Permian (289±1 Ma) ilmenite-series, ferroan granite suite which intrudes the RSZ about 3 km east from the studied area. The Fe-Cu-Zn skarn ores of Rosas are best interpreted as distal, structurally-controlled orebodies, connected to large-scale circulation of granite-related fluids in the km-sized plumbing system represented by the RSZ.</p>

Mining, Economy, and Society

2014 ◽  
Author(s):  
William O'Brien
Keyword(s):  
Stone Tools ◽  
Ore Deposits ◽  
Raw Material ◽  
Complex Life Cycle ◽  
Regional Economies ◽  
Primary Metal ◽  
Alloy Type ◽  
Scientific Analysis ◽  
Wealth Generation ◽  
The Impact

The opening chapter of this book considered different factors that influenced the availability of copper resources in prehistory. While geological distribution and technological expertise were critical, consideration must also be given to the wider societal context of production. The operation of early mines must be explained in terms of access to ore deposits and the desire and ability of different population groups to become involved in primary metal production. The impact on local and regional economies is also relevant, in terms of wealth generation through trade and the repercussions for society as a whole. Understanding the organization of this activity is a challenge. Key elements of the chaîne opératoire are often missing, such as the location of smelting sites or the workshops where objects were made. This makes it difficult to establish links between mines and the circulation of intermediate and final metal products in a wider settlement context. With stone tools it is possible to apply production indices to quantify the different stages involved in the use of a specific raw material, with a view to modelling a lithic production system in space (see Ericson 1984). This approach cannot be easily applied to metal objects, which generally have a more complex life cycle than stone tools. This began with a fundamentally different use of a raw material to create a finished object, requiring chemical as well as physical transformation. For this reason, scientific analysis of prehistoric metalwork is problematic in terms of source provenancing to specific ore deposits and mines. There is the further complication of recycling, which in some instances involved the mixing of metal from different mine sources. One approach has been to identify metal circulation zones where copper of a similar chemistry, lead isotope signature, and/ or alloy type was used (e.g. Northover 1982). Within these circulation zones various patterns of primary and secondary (recycled) metal use can be explored in the context of local workshop traditions. This provides a spatial and typochronological context in which to view the input of metal from particular mines.

A Reconstructed Subaerial Hot Spring Field in the ∼3.5 Billion-Year-Old Dresser Formation, North Pole Dome, Pilbara Craton, Western Australia

Astrobiology ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 1-38
Author(s):  
Tara Djokic ◽  
Martin J. Van Kranendonk ◽  
Kathleen A. Campbell ◽  
Jeff R. Havig ◽  
Malcolm R. Walter ◽  
...  
Keyword(s):  
Western Australia ◽  
Hot Spring ◽  
North Pole ◽  
Pilbara Craton
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