Uranium and Sm isotope studies of the supergiant Olympic Dam Cu–Au–U–Ag deposit, South Australia

2016 ◽  
Vol 180 ◽  
pp. 15-32 ◽  
Author(s):  
Maria Kirchenbaur ◽  
Roland Maas ◽  
Kathy Ehrig ◽  
Vadim S. Kamenetsky ◽  
Erik Strub ◽  
...  
Keyword(s):  
South Australia ◽  
Isotope Studies ◽  
Olympic Dam

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.

OPENING THE MAGMATIC-HYDROTHERMAL WINDOW: HIGH-PRECISION U-Pb GEOCHRONOLOGY OF THE MESOPROTEROZOIC OLYMPIC DAM Cu-U-Au-Ag DEPOSIT, SOUTH AUSTRALIA

2020 ◽  
Vol 115 (8) ◽  
pp. 1855-1870 ◽  
Author(s):  
Liam Courtney-Davies ◽  
Cristiana L. Ciobanu ◽  
Simon R. Tapster ◽  
Nigel J. Cook ◽  
Kathy Ehrig ◽  
...  
Keyword(s):  
High Precision ◽  
Volcanic Rocks ◽  
South Australia ◽  
Ore Deposits ◽  
Magmatic Zircon ◽  
Ionization Mass ◽  
Temporal Window ◽  
Precision Data ◽  
Iocg Deposit ◽  
Olympic Dam

Abstract Establishing timescales for iron oxide copper-gold (IOCG) deposit formation and the temporal relationships between ores and the magmatic rocks from which hydrothermal, metal-rich fluids are sourced is often dependent on low-precision data, particularly for deposits that formed during the Proterozoic. Unlike accessory minerals routinely used to track hydrothermal mineralization, iron oxides are dominant components of IOCG systems and are therefore pivotal to understanding deposit evolution. The presence of ubiquitous, magmatic-hydrothermal U-(Pb)-W-Sn-Mo–bearing zoned hematite resolves a range of geochronological issues concerning formation of the ~1.6 Ga Olympic Dam IOCG deposit, South Australia, at up to ~0.05% precision (207Pb/206Pb weighted mean; 2σ) using isotope dilution-thermal ionization mass spectrometry (ID-TIMS). Coupled with chemical abrasion-ID-TIMS zircon dates from host granite and volcanic rocks within and enclosing the ore-body, a confident magmatic-hydrothermal chronology is defined. The youngest zircon date from the granite intrusion hosting Olympic Dam indicates magmatism was occurring up until 1593.28 ± 0.26 Ma. The orebody was principally formed during a major mineralizing event following granite uplift and during cupola collapse, whereby the hematite with the oldest age is recorded in the outer shell of the deposit at 1591.27 ± 0.89 Ma, ~2 m.y. later than the youngest documented magmatic zircon. Hematite dates captured throughout major lithologies, different ore zones, and the ~2-km vertical extent of the deposit support ~2 m.y. of hydrothermal activity. New age constraints on the spatial-temporal evolution of the formation of Olympic Dam are considered with respect to a mantle to crustal continuum model. Cyclical tapping of magma reservoirs to maintain crystal mushes for extended time periods and incremental building of batholiths on the million-year scale prior to main mineralization pulses can explain the ~2-m.y. temporal window temporal window inferred from the data. Despite the challenge of reconciling such an extended window with contemporary models for porphyry deposits (≤1 m.y.), formation of Proterozoic ore deposits has been addressed at high-precision and supports the case that giant IOCG deposits may form over millions of years.

scholarly journals Multivariate Statistical Analysis of Trace Elements in Pyrite: Prediction, Bias and Artefacts in Defining Mineral Signatures

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 61 ◽  
Author(s):  
Marija Dmitrijeva ◽  
Nigel J. Cook ◽  
Kathy Ehrig ◽  
Cristiana L. Ciobanu ◽  
Andrew V. Metcalfe ◽  
...  
Keyword(s):  
Trace Elements ◽  
Statistical Analysis ◽  
Trace Element ◽  
South Australia ◽  
Large Datasets ◽  
Ore Deposits ◽  
Partial Replacement ◽  
Multivariate Statistical ◽  
Wide Range ◽  
Olympic Dam

Pyrite is the most common sulphide in a wide range of ore deposits and well known to host numerous trace elements, with implications for recovery of valuable metals and for generation of clean concentrates. Trace element signatures of pyrite are also widely used to understand ore-forming processes. Pyrite is an important component of the Olympic Dam Cu–U–Au–Ag orebody, South Australia. Using a multivariate statistical approach applied to a large trace element dataset derived from analysis of random pyrite grains, trace element signatures in Olympic Dam pyrite are assessed. Pyrite is characterised by: (i) a Ag–Bi–Pb signature predicting inclusions of tellurides (as PC1); and (ii) highly variable Co–Ni ratios likely representing an oscillatory zonation pattern in pyrite (as PC2). Pyrite is a major host for As, Co and probably also Ni. These three elements do not correlate well at the grain-scale, indicating high variability in zonation patterns. Arsenic is not, however, a good predictor for invisible Au at Olympic Dam. Most pyrites contain only negligible Au, suggesting that invisible gold in pyrite is not commonplace within the deposit. A minority of pyrite grains analysed do, however, contain Au which correlates with Ag, Bi and Te. The results are interpreted to reflect not only primary patterns but also the effects of multi-stage overprinting, including cycles of partial replacement and recrystallisation. The latter may have caused element release from the pyrite lattice and entrapment as mineral inclusions, as widely observed for other ore and gangue minerals within the deposit. Results also show the critical impact on predictive interpretations made from statistical analysis of large datasets containing a large percentage of left-censored values (i.e., those falling below the minimum limits of detection). The treatment of such values in large datasets is critical as the number of these values impacts on the cluster results. Trimming of datasets to eliminate artefacts introduced by left-censored data should be performed with caution lest bias be unintentionally introduced. The practice may, however, reveal meaningful correlations that might be diluted using the complete dataset.

Carbonates at the supergiant Olympic Dam Cu-U-Au-Ag deposit, South Australia. Part 1: Distribution, textures, associations and stable isotope (C, O) signatures

2020 ◽  
Vol 126 ◽  
pp. 103775 ◽  
Author(s):  
Olga B. Apukhtina ◽  
Kathy Ehrig ◽  
Vadim S. Kamenetsky ◽  
Maya B. Kamenetsky ◽  
Karsten Goemann ◽  
...  
Keyword(s):  
Stable Isotope ◽  
South Australia ◽  
Olympic Dam

Mineralization-alteration footprints in the Olympic Dam IOCG district, South Australia: The Acropolis prospect

2019 ◽  
Vol 205 ◽  
pp. 106333 ◽  
Author(s):  
Marija Dmitrijeva ◽  
Cristiana L. Ciobanu ◽  
Kathy J. Ehrig ◽  
Nigel J. Cook ◽  
Andrew V. Metcalfe ◽  
...  
Keyword(s):  
South Australia ◽  
Olympic Dam

scholarly journals Deep Crustal Structures Interpreted from Potential Field Data along the Deep Seismic Sounding Transect across Olympic Dam, South Australia

2013 ◽  
Vol 2013 (1) ◽  
pp. 1-4
Author(s):  
Irena Kivior ◽  
David Boyd ◽  
David Tucker ◽  
Stephen Markham ◽  
Francis Vaughan ◽  
...  
Keyword(s):  
Potential Field ◽  
Field Data ◽  
South Australia ◽  
Deep Seismic Sounding ◽  
Potential Field Data ◽  
Seismic Sounding ◽  
Crustal Structures ◽  
Olympic Dam

Zircon U-Pb dating in the vicinity of the Olympic Dam Cu-U-Au deposit, Roxby Downs, South Australia

1988 ◽  
Vol 83 (4) ◽  
pp. 694-709 ◽  
Author(s):  
G. E. Mortimer ◽  
J. A. Cooper ◽  
H. L. Paterson ◽  
K. Cross ◽  
G. R. T. Hudson ◽  
...  
Keyword(s):  
South Australia ◽  
Olympic Dam
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