Hawks Nest - Magnetite

South Australia Department of Mines and Energy

1995 to 1996:

• 367 percussion drillholes for a total of 20,418 m completed.
• Significant gold drill intercepts were returned in drillhole HKN99 4 m @ 4.3 g/t Au (900 m west of Raptor) and drillhole HKN53 4 m @ 0.59g/t Au (Kestrel).

SASE Pty Ltd / AuIron Energy Ltd

2000:

• 108 reverse circulation percussion (RCP) drillholes for 12,284 m completed over Kestrel and Buzzard deposits.
• 2,630 m of diamond drilling.
• Hellman and Schofield (H&S), on behalf of AuIron Energy Pty Ltd, estimated a Mineral Resource of 220 Mt @ 36% Fe (30% Fe cut-off), 38% SiO₂, 0.94%, Al₂O₃, 0.13% P₂O₅ (Measured, Indicated and Inferred) over Kestrel.
• H&S completed a Mineral Resource estimate (MRE) (Measured, Indicated and Inferred) over Buzzard of 6.7 Mt grading 60% Fe (55% Fe cut-off), 0.10% P₂O₅, 9.9% SiO₂, 1.9% Al₂O₃ and 1.5% LOI.
• Inferred Resources based on limited drilling and ground geophysics were estimated for Goshawk (148 Mt @ 35% Fe), Harrier (54 Mt @ 35% Fe), Eagle (92 Mt @ 31% Fe), Kite (30 Mt @ 51% Fe) and Falcon (25 Mt @ 32% Fe).

2003:

• Minotaur Resources completed exploration on Hawks Nest tenement EL2587 under an Access-Option Agreement with SASE Pty Ltd.
• Three semi-coincident gravity/magnetic anomalies were reverse circulation (RC) drill tested in April 2003, totalling 777 m. One hole failed to intersect the cause of the anomaly, whilst the other two failed to intersect any alteration system, although did explain the causative body.
• Two calcrete surveys were conducted across the tenement (299 samples), which upgraded some earlier anomalies and warranted an air-core drilling program.
• A 40-hole air-core program over gold-in-calcrete anomalies failed to locate significant gold in bedrock.
• Drilling results did not meet the requirements of Minotaur Resources, and consequently Minotaur Resources withdrew from the Access-Option Agreement on 2 February 2004.

Western Plains Resources 

2003:

• Pells Sullivan Meynink Pty Ltd completed a geotechnical design for feasibility-level open cut mining of Buzzard for Western Plains Resources (WPR).

2007:

• WPR drilled six RCP holes over Kite targeting shallow high-grade banded iron formation (BIF). Significant intercepts included:

• HHWPR3 – 70–124 m @ 40.9% Fe
• HNWPR6 – 5–87 m @ 41.3% Fe including 5–49 m @49% Fe

2008:

• WPR completed eight RCP drillholes (HNPR26–HNPR33) to the northeast of the Kite magnetite deposit.
• Four RCP drillholes with diamond tails were completed over Buzzard for a total of 445 m core drilled – predominantly PQ3 with minor HQ3.
• WPR completed a Mineral Resource estimate over the Buzzard and Tui deposits. In addition, a reserve statement based on the WPG resource was prepared by AMDAD (Australian Mine Design and Development).
• WPR complete a Kestrel Pit optimisation – unconstrained at 0% Fe cut and at 25% Fe cut. At a 25% Fe cut, the optimised pit at Kestrel resulted in 216 Mt grading 35.7% Fe.

One Steel Ltd / Arrium Ltd

2010:

• Central Iron Pty Ltd incorporated in 2010 and operating as a subsidiary of Arrium Limited.

2011:

• WPR sells all South Australian iron ore assts for $320 million to One Steel Limited.
• One Steel Limited changes its name to Arrium Limited in July 2012.
• Arrium operate multiple subsidiary companies including Southern Iron Pty Ltd and Central Iron Pty Ltd. The Hawks Nest Project is operated by Central Iron Pty Ltd.

2012:

• Coffey Mining Ltd, on behalf of OneSteel Manufacturing Pty Ltd, completed an examination of the resource and reserve estimates complied for the Buzzard and Tui deposits of the Hawks Nest Project.

2013:

• Exploration work completed included:

• Central Iron Pty Ltd drilled 29 RC and one diamond drillhole (DDH) to infill and improve the Buzzard and Tui resources. Drilling generally targeted specific zones of the deposit, and was not on any specific grid, although some were spaced at 50 m x 50 m, notably at Tui.
• Ongoing groundwater monitoring (as required by various licences and the access agreement with McDouall Peak Station stakeholders).
• Parsons Brinckerhoff complete a Hawks Nest Development – Valued User Requirement Specification.
• An airborne magnetic survey at 50 m line spacing over the entire tenement and initial ground gravity survey.

• A resource estimation of Buzzard and Tui deposits:

• Buzzard: 19.0 Mt grading 60.5% Fe (50% Fe cut-off), 9.70% SiO₂, 1.62% Al₂O₃, 0.07% P and 1.06% LOI.
• Tui: 3.49 Mt grading 59.9% Fe (50% Fe cut-off), 11.67% SiO₂, 0.87% Al₂O₃, 0.08% P and 0.94% LOI

2014:

Exploration work completed included:

• Drilling of 47 RC holes (8,018 m) and one diamond tail (24.9 m). Drilling focused on the Buzzard hematite resource with a series of holes being drilled on 25 m x 25 m spacing to better understand the complexity of mineralisation. Little drilling was done outside of the Buzzard resource.
• Other fieldwork on the tenement included: installation of four groundwater monitoring bores, ongoing groundwater monitoring (as required by various licences and the access agreement with McDouall Peak Station stakeholders), downhole geophysical surveys and rehabilitation.
• A detailed gravity survey completed by Daishsat Geodetic Surveyors (Daishsat) over the western parts of Hawks Nest Project. This survey infilled and extended the coverage of the gravity surveying completed over the Buzzard area in November 2013. In total, over Hawks Nest East, 5,278 stations were surveyed at 25 m spacings along north-south orientated lines 50 m apart, covering an area of approximately 6.95 km². Over Hawks Nest West, 3,372 gravity stations on a 50 m x 5 0m square grid covering an area of 8.45 km² were collected.
• Southern Geoscience Consultants (SGC) was engaged to design, oversee, process, and interpret the Daishsat collected gravity survey blocks over Hawks Nest East (colloquially named Area 1 by SGC) and Hawks Nest West (Area 2 which covers the Eagle, Falcon and Kite prospects). There was a focus on identifying additional areas of interest for potential hematite mineralisation.
• Quality assurance/quality control report on Buzzard completed.
• Update of the 2013 Buzzard and Tui resource models to include drilling not captured in the 2013 model.

2015:

• Exploration work completed included:

• The regional drilling program consisted of 35 RC holes (3,744 m) drilled at Hawks Nest East and 36 RC holes (2,812 m) drilled at Hawks Nest West, following up historical drilling around the Kite prospect and new geophysical anomalies throughout the western portion of EL6395 (then EL5399). The mineralisation observed at Hawks Nest East consisted of hematite or magnetite and the dip of mineralisation varied from sub vertical to flat lying. Drilling at Hawks Nest East intersected hematite and magnetite mineralisation at multiple targets.
• Four new prospects were identified – Hobby, Sparrow Hawk, Grey Goshawk (magnetite) and Bearded Vulture. Intersections included: high-grade hematite and magnetite, hematised BIF and lower grade, friable hematite/magnetite. Further drilling is required to understand the extent of mineralisation and to define potential resources at these prospects.
• Drilling over Tui and Buzzard prospects. At Tui, drilling consisted of two drillholes (344 m) targeting up-dip extension of mineralisation and a gravity high to the northeast. At Buzzard, drilling consisted of 30 RC holes (3,891 m). Drilling was to the southwest where mineralisation style and species were similar to Buzzard but also contained considerable goethite, possibly representing supergene enrichment. Some holes were drilled inside the resource area to confirm interpretation and continuity of mineralisation.

• An MRE was completed by Arrium Mining over Kestrel. The deposit had been drilled on lines 100 m apart over a strike length of some 1,200 m. Drilling consists of 16 diamond and 93 RC percussion holes. Holes were generally 50 m apart on section. Most holes were limited to a depth of 135 m below surface. The estimate comprised 231.5 Mt grading 36.5% Fe (30% Fe cut-off), 38.5% SiO₂, 0.88% Al₂O₃, 0.06% P, 0.09% S and 0.84% LOI.

2016:

• Arrium goes into voluntary administration.
• Exploration work completed included:

• Desktop studies as part of a regional geological review of Central Iron and Southern Iron tenements and targets, particularly in the light of the insights from the recent GSSA Eastern-Central Gawler Craton Solid Geology interpretation
• Data compilation and review with potential farm-in parties
• Continued rehabilitation of drillholes with 148 rehabilitated drill sites (including historical drilling) to date.

2017:

• Arrium acquired by Liberty House Group, an industrial and metals company founded in the United Kingdom in 1992 by industrialist, Sanjeev Gupta.
• Liberty House Group purchase all except Central and Southern Iron.
• Exploration work completed included:

• Desktop studies as part of a regional geological review of Central Iron and Southern Iron tenements and targets, particularly in the light of the insights from the recent GSSA Eastern-Central Gawler Craton Solid Geology interpretation
• Data compilation and review with potential farm-in parties
• Magnetite target review
• Continued rehabilitation of drill sites.

2018:

• Exploration work completed included:

• Desktop studies as part of a regional geological review of Central Iron and Southern Iron tenements and targets, particularly in the light of the insights from the recent GSSA Eastern-Central Gawler Craton Solid Geology interpretation.
• Magnetite target review.
• Continued rehabilitation of drill sites.
• Diamond drilling at a Kestrel target to obtain sample for further metallurgical testwork. Four drillholes completed for a total of 353.1 m.

2019:

• Exploration work completed included:
  • Desktop studies as part of a regional geological review of Central Iron and Southern Iron tenements and targets, particularly in the light of the insights from the recent GSSA Eastern-Central Gawler Craton Solid Geology interpretation.
  • Magnetite target review.
  • Continued rehabilitation of drill sites.
  • Diamond drilling at Kestrel project (two drillholes for 148.4 m).

RC drilling at Harrier project including 10 RC holes for a total of 1,612 m to test a magnetic anomaly and for metallurgical testwork. None of the Harrier drillholes intersected any mineralisation grading greater than 50% Fe.