Australia

Higginsville Gold Operations (HGO)

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Categories

Overview

Mine TypeOpen Pit & Underground
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
  • Longhole open stoping
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ShapshotHigginsville Gold Operation (HGO) comprises open pit and underground gold deposits, the 1.6 Mtpa gold processing facility, and in addition, Karora acquired the 1.0 Mtpa Lakewood mill in July 2022. Mining in 2022 was mainly conducted at the Spargos open pit in the Higginsville Greater area and at the Aquarius and Two Boys underground operations in the Higginsville Central Area.

Owners

SourceSource
CompanyInterestOwnership
Karora Resources Inc. 100 % Indirect
Karora's principal asset are its 100% interest in HGO (represented by a 100% interest in Karora Australia Pty Ltd.)

Contractors

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Deposit type

  • Vein / narrow vein
  • Mesothermal
  • Paleoplacer
  • Sediment-hosted

Summary:

The characteristics of the gold deposits at Higginsville are consistent with the greenstone-hosted quartz-carbonate vein (mesothermal) gold deposit model. Throughout the Higginsville Gold Operations, a significant proportion of gold deposits are hosted by sediments within Southern Palaeochannel networks. Mineralised zones comprise both placer gold, normally near the base of the channel-fill sequences, and chemically-precipitated secondary gold within the channel-fill materials and underlying saprolite. These gold concentrations commonly overlie, or are adjacent to, primary mineralised zones within Archaean bedrock. Outcrop is generally poor, due to extensive ferruginisation, calcareous soils, aeolian sands and extensive areas of remnant lacustrine and fluvial sediments. The result is a complex, layered regolith, with considerable chemical re-mobilisation and re-deposition (Lintern et. al., 2001). Higginsville is located almost entirely within the well-mineralised Archean Kalgoorlie Terrane, between the gold mining centres of Norseman and Saint Ives. The Archaean stratigraphy has a general northward trend comprising multiply deformed ultramafic – gabbro – basalt successions adjoined by sediments to the west and east. Shearing and faulted contacts are common. The units have been structurally repeated by east over west thrust faulting. The HGO can be sub-divided into six major geological domains: - Trident line-of-lode; - Chalice; - Lake Cowan; - Southern palaeochannels; - Mount Henry; - Polar Bear Group; and - Spargos Project Area. Trident line-of-lode The majority of mineralisation projects along the Trident line-of-lode are hosted within the Poseidon Gabbro and high-MgO dyke complexes in the south. The Poseidon Gabbro is a thick, weakly- differentiated gabbroic sill (Newman et. al., 2005), which strikes north south and dips 60° to the east, is over 500m thick and 2.5km long. The gabbro is broadly zoned (Zones 1 - 5), with Zone 3 considered the most favourable for mineralisation: - Zone 1 is interpreted as an ultramafic cumulate base; - Zone 2 is a feldspar-phyric mafic unit; - Zone 3 is an equigranular, feldspar-quartz phyric unit. - Zone 4 is a bladed amphibole unit; and - Zone 5 is an equigranular, feldspar-amphibole phyric unit. Chalice The Chalice deposit is located within a north south trending, 2-3km wide greenstone terrane, flanked on the west calc-alkaline granitic rocks of the Boorabin Batholith and to the east by the Pioneer Dome Batholith. The mafic-ultramafic rocks of the greenstone terrane comprise upper greenschist to middle amphibolite facies metamorphosed, high-magnesium basalt, minor komatiite units and interflow clastic sedimentary rocks intruded by a complex network of multigenerational granite, pegmatite and porphyry bodies. The dominant unit that hosts gold mineralisation is a fine grained, weak to strongly foliated amphibole-plagioclase amphibolite, with a typically lepidoblastic (mineralogically aligned and banded) texture. It is west-dipping and generally steep, approximately 60°-75°. It is typically more competent than the ultramafic unit. Lake Cowan The area is situated near the centre of a regional anticline between the Zuleika and Lefroy faults, with the local geology of the area made more complex by the intrusion of the massive Proterozoic Binneringie dyke. The Binneringie dyke varies locally from a hornblende dominated dolerite to a feldspar dominated granodiorite, is medium to coarse grained, and is complexly interrelated to the mineralised structures in the Lake Cowan area. In a break of form for these generally east-northeast – west-southwest trending dyke systems, at Lake Cowan the Binneringie dyke follows the deep seated crustal weaknesses north and south for some distance, in the process interfering with the pre- existing mineralisation on a large scale. The majority of mineralisation at the Lake Cowan Mining Centre is hosted within an enclave of Archaean material surrounded by the Binneringie dyke. Southern Palaeochannels Throughout the Higginsville Gold Operations, a significant proportion of gold deposits are hosted by sediments within the Southern Palaeochannel network. Mineralised zones comprise both placer gold, normally near the base of the channel-fill sequences, and chemicallyprecipitated secondary gold within the channel-fill materials and underlying saprolite. These gold concentrations commonly overlie, or are adjacent to, primary mineralised zones within Archaean bedrock. Polar Bear Group The geology at Polar Bear is dominated by complexly deformed Achaean greenstone assemblages of the Norseman-Wiluna Greenstone Belt which have been metamorphosed to upper greenschist facies. The major regional structures in the area are the Boulder-Lefroy Fault, located approximately 10km northeast of the project area, the Mission Fault located in the southern portion of the package, and the Black Knob Fault that transects the central portion of the project. Spargos Project Area The Spargos Project occurs within Coolgardie Domain of the Kalgoorlie Terrane. The western boundary of the Domain is marked by the Ida Fault, a crustal-scale suture that separates the eastern goldfields from older terranes to the west. Its eastern margin is marked by the Zuleika Fault. The geological setting comprises tightly-folded north-south striking ultramafic and mafic volcanic rocks at the northern closure Widgiemooltha Dome.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityUnits2022202120202019201820172016
Gold oz 0000000000000000000055,95884,59591,371
All production numbers are expressed as metal in doré.

Operational metrics

Metrics202220212020201920182017
Annual processing capacity 0000001.3 Mt1.3 Mt
Ore tonnes mined 000000000000784,004 t952,576 t
Tonnes processed 0000000000000001,189,400 t1,232,184 t
Waste 00000000000000

Production Costs

CommodityUnits202220212020201920182017
Total cash costs (sold) Gold AUD 00000000 00000000 00000000
All-in sustaining costs (AISC) Gold AUD 1,520 / oz   1,565 / oz   1,243 / oz  
C1 cash costs Gold AUD 1,375 / oz   1,398 / oz   1,069 / oz  
All-in costs Gold AUD 1,745 / oz   1,940 / oz   1,402 / oz  
Net of By-Product.

Financials

Units20222021202020182017
Capital expenditures M AUD 16.7  
Revenue M  ....  Subscribe  ....  Subscribe  ....  Subscribe 94.8  AUD 139.3  AUD
Operating Income M  ....  Subscribe  ....  Subscribe  ....  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Source Source
Job TitleNamePhoneEmailProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Apr 25, 2024
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Dec 31, 2020
....................... Subscription required ....................... Subscription required Subscription required Aug 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Aug 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Aug 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 8, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 8, 2023
....................... Subscription required ....................... Subscription required ........... Subscription required ........... Subscription required Subscription required Aug 1, 2023

Total WorkforceYear
Subscription required 2022
Subscription required 2020

Aerial view:

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