Geology and Mineralogical Zonation of the Olympic Dam Iron Oxide Cu-U-Au-Ag Deposit, South Australia

2012 ◽  
Author(s):  
Kathy Ehrig ◽  
Jocelyn McPhie ◽  
Vadim Kamenetsky
Keyword(s):  
Iron Oxide ◽  
South Australia ◽  
Olympic Dam

Hematite geochemistry and geochronology resolve genetic and temporal links among iron-oxide copper gold systems, Olympic Dam district, South Australia

2019 ◽  
Vol 335 ◽  
pp. 105480 ◽  
Author(s):  
Liam Courtney-Davies ◽  
Cristiana.L. Ciobanu ◽  
Max R. Verdugo-Ihl ◽  
Marija Dmitrijeva ◽  
Nigel J. Cook ◽  
...  
Keyword(s):  
Iron Oxide ◽  
South Australia ◽  
Copper Gold ◽  
Olympic Dam

scholarly journals Feldspar mineralogy and rare-earth element (re)mobilization in iron-oxide copper gold systems from South Australia: a nanoscale study

2018 ◽  
Vol 82 (S1) ◽  
pp. S173-S197 ◽  
Author(s):  
Alkis Kontonikas-Charos ◽  
Cristiana L. Ciobanu ◽  
Nigel J. Cook ◽  
Kathy Ehrig ◽  
Roniza Ismail ◽  
...  
Keyword(s):  
Iron Oxide ◽  
South Australia ◽  
Potassium Feldspar ◽  
Micro Scale ◽  
Silicate Inclusions ◽  
Nanoscale Characterization ◽  
Copper Gold ◽  
Olympic Dam ◽  
Alkali Feldspars

ABSTRACTNanoscale characterization (TEM on FIB-SEM-prepared foils) was undertaken on feldspars undergoing transformation from early post-magmatic (deuteric) to hydrothermal stages in granites hosting the Olympic Dam Cu-U-Au-Ag deposit, and from the Cu-Au skarn at Hillside within the same iron-oxide copper-gold (IOCG) province, South Australia. These include complex perthitic textures, anomalously Ba-, Fe-, or REE-rich compositions, and REE-flourocarbonate + molybdenite assemblages which pseudomorph pre-existing feldspars. Epitaxial orientations between cryptoperthite (magmatic), patch perthite (dueteric) and replacive albite (hydrothermal) within vein perthite support interface-mediated reactions between pre-existing alkali-feldspars and pervading fluid, irrespective of micro-scale crystal morphology. Such observations are consistent with a coupled dissolution-reprecipitation reaction mechanism, which assists in grain-scale element remobilization via the generation of transient interconnected microporosity. Micro-scale aggregates of hydrothermal hyalophane (Ba-rich K-feldspar), crystallizing within previously albitized areas of andesine, reveal a complex assemblage of calc-silicate, As-bearing fluorapatite and Fe oxides along reaction boundaries in the enclosing albite-sericite assemblage typical of deuteric alteration. Such inclusions are good REE repositories and their presence supports REE remobilization at the grain-scale during early hydrothermal alteration. Iron-metasomatism is recognized by nanoscale maghemite inclusions within ‘red-stained’ orthoclase, as well as by hematite in REE-fluorocarbonates, which reflect broader-scale zonation patterns typical for IOCG systems. Potassium-feldspar from the contact between alkali-granite and skarn at Hillside is characterized by 100–1000 ppm REE, attributable to pervasive nanoscale inclusions of calc-silicates, concentrated along microfractures, or pore-attached. Feldspar replacement by REE-fluorcarbonates at Olympic Dam and nanoscale calc-silicate inclusions in feldspar at Hillside are both strong evidence for the role of feldspars in concentrating REE during intense metasomatism. Differences in mineralogical expression are due to the availability of associated elements. Lattice-scale intergrowths of assemblages indicative of Fe-metasomatism, REE-enrichment and sulfide deposition at Olympic Dam are evidence for a spatial and temporal relationship between these processes.

The ecology of sympatric scincid lizards (Ctenotus) in arid South Australia

1998 ◽  
Vol 46 (6) ◽  
pp. 617 ◽  
Author(s):  
J. L. Read
Keyword(s):  
Home Range ◽  
Environmental Conditions ◽  
Plant Material ◽  
Reproductive Effort ◽  
Arid Zone ◽  
South Australia ◽  
Early Summer ◽  
Home Ranges ◽  
Local Species ◽  
Olympic Dam

Ctenotus skinks are the most diverse and abundant diurnal reptile genus at Olympic Dam, in the South Australian arid zone. The home range, demography, reproduction and diet of five syntopic Ctenotus species was studied over a 6-year period in chenopod shrubland. Longevity frequently exceeded three years in C. regius, four years in C. schomburgkii and five years in C. leonhardii, with a 7-year-old specimen of C. leonhardii being recorded. Females of most species tended to be larger and lived longer than males. Two eggs were typically laid by each species in early summer. Annual reproductive effort, particularly in C. leonhardii, varied considerably depending upon the prevailing environmental conditions. All local species apparently occupied home ranges, with maximum recapture radii in different species of 40–60 m. Ctenotus appear to be unspecialised insectivores, although plant material and lizards are sometimes eaten by the larger species.

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