On the 6 August 2012 Gascoyne acquired an 80% interest in the advanced Dalgaranga gold project and surrounding exploration tenements from private tenement holders. The Dalgaranga project is located approximately 70km by road NW of Mt Magnet in the Murchison gold mining region of Western Australia and covers the majority of the Dalgaranga greenstone belt. After discovery in the early 1990’s, the project was developed and from 1996 to 2000 produced 229,000oz’s of gold from predominantly the Gilbeys deposit with reported cash costs of less than $350/oz.
The project contains a JORC Measured, Indicated & Inferred resource of 23.7Mt @ 1.4g/t Au for 1,051,000 ounces of contained gold.
Significant exploration potential also remains outside the known resources. On September 25th, 2013 Gascoyne announced the granting of the Dalgaranga Mining Lease.
A scoping study has commenced to investigate the development options for the project.
The project lies in the Dalgaranga Greenstone Belt in the Murchison Province of Western Australia. The NE trending belt consists of basalts and sediments - mainly black shales. Felsic volcanic rocks outcrop on the western side of the belt. The sequence is intruded by large gabbro complexes in the north (Mt Farmer, Mt Charles) and to the west (Dalgaranga Hill). The stratigraphy has been folded into two regional synforms which plunge in opposite directions separated by a regional fault/shear that trends along the western side of the Mt Farmer gabbro sill westwards to the south side of the gabbroic Dalgaranga Hill. The Dalgaranga Greenstone Belt is intruded by a number of post tectonic granites separated by zones of amphibolite and mafic schists intruded by pegmatites. East-west trending Proterozoic dykes of dolerite and gabbro intrude the Greenstone sequences.
The Dalgaranga Project area is characterised by broad areas of alluvium and sheetwash associated with major drainage systems. Within this area remnant windows or rises of residual lateritic nodules of ferruginous duricrust occur. Exposures of saprolitic clays border these lateritic rises in the Golden Wings deposit and Vickers prospect areas and east of the Gilbeys deposit. South and east of Gilbeys outcrops of gabbro, pyroxenite, black shale and NW/SE trending zones of quartz veins occur. The Gilbeys deposit is located on the western limb of a southerly plunging anticline within a dextral ductile shear zone. The shear zone trends to the NE and dips NW sub parallel to the stratigraphy at approximately 40 -70 degrees.
Significant gold mineralisation remains at depth and along strike of the Gilbeys open pit which has been mined down at its deepest point to approximately 130m below surface. The Gilbeys deposit occurs within a broad (100-200m wide) shear zone that trends NE for over 2km. Gold mineralisation is associated with quartz-pyrite-carbonate veins within a sheared porphyry-shale package. Strong weathering/oxidation occurs up to 100m below the surface. Mineralisation dips 45 to 60 degrees to the NW and is highly predictable down dip. Considerable gold mineralisation lies directly below the base of the pit which could be readily accessed through modest pit cut-backs. A new remodelled resource estimate for the Gilbeys deposit was announced on August 1, 2013. THe combined Indicated & Inferred Resource for the Gilbeys deposit now stands at 21.8Mt @1.4g/t Au for 949,000 ounces of gold
Golden Wings Deposit
Gascoyne announced (24th February 2016) the Golden Wings an Indicated and Inferred resource was updated to for the Golden Wings deposit of 2.0Mt @ 1.6 g/t gold for 101,000 ounces of gold (using a 0.5 g/t cut-off). The resource has been estimated following the discovery of an east-west high grade gold trend at Golden Wings in Gascoyne's initial drill program at Dalgaranga.
The deposit extends for over 400m east - west and remains open at depth and along strike. The gold mineralisation extends to surface with 46% of the resource classified as "free dig" oxide which is not expected to require blasting. All of the Indicated Resource (300,000t @ 4.0 g/t for 38,000 oz) is classified as either Oxide or Transitional. The Resource is on the granted Dalgaranga Mining Lease and is proximal to existing infrastructure.
The host rocks at Golden Wings consist of a sequence of high magnesium basalts, basalt and interflow sediments (black shales) and minor porphyries. Quartz gabbro occurs on the northern side of the prospect. These rock units have been sheared to form quartz biotite schists, with the strike of the geology interpreted to be east-west in a broad shear zone. A well-developed weathering profile occurs at Golden Wings; at surface a mixed hardpan residual pisolitic laterite horizon occurs which is approximately 5m thick, below which residual mottled and saprolitic clay zones are developed, in places strong oxidation occurs to a depth of 80m or more.
Recent infill an extension RC drilling at the Golden wings Deposit has intersected high grade gold. The infill drilling has confirmed the Company's geological model and intersected wide high grade mineralisation including a zone of 21m @ 4.5 g/t gold.
A Scoping Study has commenced to determine the optimum development options of the Dalgaranga project. The options being considered are:
Having multiple options provides the Company with an excellent opportunity for short term cas-flow from the Dalgaranga project, which lies on a granted Mining Lease, close to several operating gold mines.
A series of pit optimisation studys, metallurgical testwork and environmental studies are in progress on the Gilbeys and Golden Wings resources. Metallurgical testwork todate shows excellent gold recoveries of +98% within 24 hours of CIL testwork for both deposits and heap leach tests showing recoveries between 65 and 77%.
Dalgaranga Exploration Update
The recently completed exploration drill program has identified a number of mineralised trends outside the known resources. The exploration was focused near the Golden Wings Deposit and extensions to the east and west. This drilling targeted predominantly the east-west trending structural zone that hosts the Golden Wings deposit, and unexplored areas in the NW area of the Dalgaranga Mining lease. Initial Aircore drilling was carried out on north-south lines at 100m line spacing to the north, north-east and north-west of the Golden Wings deposit followed by larger step outs into unexplored covered areas particularly to the north of the Gilbeys deposit.
Golden Wings North: A number of short lines of north south orientated drilling targeted parallel east-west mineralised trends 50 - 200m north of Golden Wings deposit, 4m composite intersections include 8m @ 1.4 g/t gold from 56m (DGAC085), 4m @ 5.3g/t gold from 20m (DGAC087) and 4m @ 2.5 g/t gold from 56m (DGAC098).
Golden Wings East: Some 250m to the NE of Golden Wings a zone of 4m @ 1.9 g/t gold from 48m (DGAC149).
Exploration Reconnaissance: A series of very wide spaced Aircore holes (200m spaced holes on 800m spaced lines) were drilled some 1600m north of the Gilbeys deposit and around 3,000m west of the Golden Wings deposit, close to the boundary of the granted exploration licence (Gascoyne owns 80% of the adjoining exploration tenement application). A broad interval of 42m @ 0.5 g/t gold from 64m to the EOH, including 4m @ 2.6g/t gold, was intersected in DGAC194. This is a very encouraging intersection in an area which has no historical exploration. The very wide spaced drilling lies on a north-east trending fault zone discernible from aeromagnetic data – this trend is sub parallel to the Gilbeys shear zone and is unexplored, opening up further exploration targets in the Dalgaranga area.