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The Hekeia Gabbro in the Longwood Range of Southland, New Zealand, is prospective for platinum group element mineralisation. Recently acquired geological and isotopic data, combined with reinterpreted aeromagnetic data, provide new constraints on the three-dimensional extent and internal structure of the gabbro. Direct observations of in situ subvertical igneous layering give confidence that most curvilinear aeromagnetic patterns are largely caused by macroscopic primary igneous layering. Steep magnetic gradients can be used to reliably define the areal limits of the Hekeia Gabbro and show that it extends to depths of over 1 km. Neodymium isotope ratios distinguish Hekeia Gabbro from younger gabbros and confirm the presence of at least two surface outcrops of Hekeia Gabbro a few kilometres west of the main body. Hekeia Gabbro is interpreted to be part of a 5 km thick Late Permian lopolith that was subsequently deformed and intruded by Triassic plutons. (Authors.), The Hekeia Gabbro in the Longwood Range of Southland, New Zealand, is prospective for platinum group element mineralisation. Recently acquired geological and isotopic data, combined with reinterpreted aeromagnetic data, provide new constraints on the three-dimensional extent and internal structure of the gabbro. Direct observations of in situ subvertical igneous layering give confidence that most curvilinear aeromagnetic patterns are largely caused by macroscopic primary igneous layering. Steep magnetic gradients can be used to reliably define the areal limits of the Hekeia Gabbro and show that it extends to depths of over 1 km. Neodymium isotope ratios distinguish Hekeia Gabbro from younger gabbros and confirm the presence of at least two surface outcrops of Hekeia Gabbro a few kilometres west of the main body. Hekeia Gabbro is interpreted to be part of a 5 km thick Late Permian lopolith that was subsequently deformed and intruded by Triassic plutons. (Authors.)

The Longwood Range, New Zealand, includes extensive outcrops of the Hekeia Gabbro, a Permian mafic-ultramafic layered plutonic complex which was intruded into volcanogenic sediments. The Gabbro is possibly a variation of an Ural-Alaska type of intrusion characteristic of arc settings. There is localised enrichment in platinum group elements, but no platinum group minerals have been identified. Analysis of drill hole samples show that the most PGE-enriched rocks (up to 1 ppm) are gabbros and troctolites, rather than the more ultramafic rocks. The Hekeia Gabbro is extensively altered in places to amphibolite facies and/or greenschist facies assemblages and there has been minor remobilisation and localised enrichment of Pt, Pd and/or Cu in association with some of this alteration. Primary igneous magnetite was replaced during alteration, and alteration magnetite has formed in some zones. Detrital isoferroplatinun, sperrylite, Os-Ru-Ir alloys and cooperite-braggite solid solution minerals occur in palaeoplacers on the southern slopes of the Hekeia Gabbro., The Longwood Range, New Zealand, includes extensive outcrops of the Hekeia Gabbro, a Permian mafic-ultramafic layered plutonic complex which was intruded into volcanogenic sediments. The Gabbro is possibly a variation of an Ural-Alaska type of intrusion characteristic of arc settings. There is localised enrichment in platinum group elements, but no platinum group minerals have been identified. Analysis of drill hole samples show that the most PGE-enriched rocks (up to 1 ppm) are gabbros and troctolites, rather than the more ultramafic rocks. The Hekeia Gabbro is extensively altered in places to amphibolite facies and/or greenschist facies assemblages and there has been minor remobilisation and localised enrichment of Pt, Pd and/or Cu in association with some of this alteration. Primary igneous magnetite was replaced during alteration, and alteration magnetite has formed in some zones. Detrital isoferroplatinun, sperrylite, Os-Ru-Ir alloys and cooperite-braggite solid solution minerals occur in palaeoplacers on the southern slopes of the Hekeia Gabbro.

The Goondicum industrial minerals deposit, Queensland, is hosted in the Goondicum Crater in a roughly circular 6 km diameter layered gabbro complex. Significant ilmenite, apatite, titano-magnetite and feldspar mineralisation is present in a weathered horizon up to 25 m thick. The initial project was abandoned in 2008 as expected production performance wasn't achieved. It was taken over for redevelopment the following year. A drilling programme was carried out to collect new data on apatite distribution and to confirm ilmenite and titano-magnetite resources. A block model was created using 1 m high blocks, wireframes defining the main material types, and 2.5 m thick horizontal search ellipsoids with a radial pattern. The deposit was 'flattened' prior to modelling. To assist with the economic evaluation of the project, each block was assigned a net dollar value based on economic parameters including anticipated revenues and costs. At a zero net value per block, comparable to a break-even cut-off grade of 4% ilmenite equivalent, the indicated plus measured resource is estimated at 51 000 000 t averaging 4.1% ilmenite, 1.9% apatite and 2.5% titano-magnetite., The Goondicum industrial minerals deposit, Queensland, is hosted in the Goondicum Crater in a roughly circular 6 km diameter layered gabbro complex. Significant ilmenite, apatite, titano-magnetite and feldspar mineralisation is present in a weathered horizon up to 25 m thick. The initial project was abandoned in 2008 as expected production performance wasn't achieved. It was taken over for redevelopment the following year. A drilling programme was carried out to collect new data on apatite distribution and to confirm ilmenite and titano-magnetite resources. A block model was created using 1 m high blocks, wireframes defining the main material types, and 2.5 m thick horizontal search ellipsoids with a radial pattern. The deposit was 'flattened' prior to modelling. To assist with the economic evaluation of the project, each block was assigned a net dollar value based on economic parameters including anticipated revenues and costs. At a zero net value per block, comparable to a break-even cut-off grade of 4% ilmenite equivalent, the indicated plus measured resource is estimated at 51 000 000 t averaging 4.1% ilmenite, 1.9% apatite and 2.5% titano-magnetite.

The deposit is a Ni-Co enriched laterite, formed over intensely serpentinised peridotites. Basement lithologies consist predominantly of serpentinised dunite, with lesser massive serpentinite shear, gabbro and harzburgite. Investigation of the deposit has defined 17 different varieties of saprolite, ferralite (limonite) and ferricrete. Different combinations of these varieties form three distinct lateritic associations: the Hard, Soft and Dyke associations. Recognition of key textural and mineralogical features in each association, an understanding of basement geology and an awareness of current climatic conditions suggest that both the Hard and Soft associations formed under relatively dry climatic conditions with the Soft association reflecting much poorer groundwater drainage than the Hard. The Dyke association formed from a gabbroic basement and has also been affected by restricted groundwater drainage caused by poorly permeable marginal serpentinite shears., The deposit is a Ni-Co enriched laterite, formed over intensely serpentinised peridotites. Basement lithologies consist predominantly of serpentinised dunite, with lesser massive serpentinite shear, gabbro and harzburgite. Investigation of the deposit has defined 17 different varieties of saprolite, ferralite (limonite) and ferricrete. Different combinations of these varieties form three distinct lateritic associations: the Hard, Soft and Dyke associations. Recognition of key textural and mineralogical features in each association, an understanding of basement geology and an awareness of current climatic conditions suggest that both the Hard and Soft associations formed under relatively dry climatic conditions with the Soft association reflecting much poorer groundwater drainage than the Hard. The Dyke association formed from a gabbroic basement and has also been affected by restricted groundwater drainage caused by poorly permeable marginal serpentinite shears.

The Three Mile Hill gold orebody at Coolgardie, Western Australia, is confined to a single unit within a layered gabbro dyke. The medium-sized open pit is typified by hard, competent, fresh rock conditions from near surface. The project involved construction of a haulage tunnel or decline located in the wall of the open pit, in place of a conventional pit access ramp. Works undertaken included excavation, support, ventilation, dewatering, installation of services, commissioning and monitoring. Prior to implementation, pit slopes and designs were constrained by infrastructure and a main road to the north and adjoining leases to the south-east. Back-analysis indicates that implementation resulted in a cost saving of as much as Aus, The Three Mile Hill gold orebody at Coolgardie, Western Australia, is confined to a single unit within a layered gabbro dyke. The medium-sized open pit is typified by hard, competent, fresh rock conditions from near surface. The project involved construction of a haulage tunnel or decline located in the wall of the open pit, in place of a conventional pit access ramp. Works undertaken included excavation, support, ventilation, dewatering, installation of services, commissioning and monitoring. Prior to implementation, pit slopes and designs were constrained by infrastructure and a main road to the north and adjoining leases to the south-east. Back-analysis indicates that implementation resulted in a cost saving of as much as Aus