The Springdale Copper-Gold Project comprises one exploration licence application (EL5975) which is pending at the application stage (applied 21/5/2020). It has an area of 70 BL (~217 km2). The Springdale Project, in the highly prospective central east Lachlan Fold Mineral Belt, is located 330km WSW of Sydney. The town of Temora lies 16 km to the west of the tenement.
Figure 1: Springdale Project – Location & Access
The area has been explored by several companies for a variety of commodities, but predominately gold.
The Springdale Project area is considered prospective for intrusive related gold mineralisation. The tenement area is dominated by a sequence of Silurian to Devonian siliciclastic sediments, including calcareous and carbonaceous units of the Combaning Formation. These sediments have been intruded by a complex suite of felsic to ultramafic intrusives. Numerous structures are interpreted to pass through the area, many of which are closely associated with historic gold workings.
The Springdale Project represents a series of historical gold mines hosted in the Silurian sedimentary rocks in the southern Lachlan fold belt. More than 20 historical gold workings are known within the area, along with N-S trending structures at an angle to the Springdale fault zone, generally hosted by sediments in close proximity to intrusives.
Apart from intrusive related gold mineralisation, other potential styles of mineralisation are thought to include structurally controlled gold mineralisation as well as intrusive related nickel, copper, tin or tungsten. Numerous stocks and dykes associated with acid volcanics were potentially hydrothermally altered and may have been gold mineralised targets.
The gold mineralisation is often associated with a halo of arsenic-rich pyrite and sericite (phyllic alteration), the pyrite halos can be detected with induced polarisation (IP) geophysical methods. It is recommended that the exploration plan includes mapping the broader alteration zones with modern IP methods and drill test IP anomalies to target bulk tonnage sedimentary hosted gold associated with broad pyrite (phyllic) alteration zones.
Local Geology
The Springdale tenement is situated to the east of the Gilmore suture on the eastern margin of the Springdale Rift. The area is underlain by siltstones, sandstone and coarse quartzite cobble conglomerates, which appear to belong to the Combaning Formation (Silurian age). A dominant approximate 3300 cleavage is observed throughout the licence, possibly a reflection of deformation associated with the Gilmore Suture. Several north-westerly regional structures are also present for distances up to 20km, such as structures dissecting the Gundibindyal Granite and Merri Hill areas (Figure 2).
Figure 2: Springdale Project – Local Geology (NSW Seamless Geology)
Porphyries with their related acid volcanics in the south-east of the licence intrude quartzite pebble conglomerate sediments, interpreted to be part of the Combaning Formation. These acid volcanics may be coeval with the nearby Gundibindyal Granites and/or other intrusives in the area, the volcanics have been grouped with the Stockinbingal Formation but the contact relationship with the Gundibindyal Granite remains unclear.
Several mafic intrusives occur within the Springdale Licence including north-trending dolerite dykes, a circular reversely magnetised olivine dolerite/basalt breccia pipe at the Yarra Glen prospect and ultramafics and serpentinites at the Merri Hill Prospect.
Mineralisation
Several major structures are present within the licence with northerly and northwesterly trends as seen in the regional aeromagnetic imaging. The Springdale Fault on the western side of the project is an N-S splay off the major crustal-scale Gilmour Fault to the south. Magnetic highs in the northern area are related to granitic intrusions (Figure 3).
Figure 3: Regional aeromagnetic image showing main structural trends
More than 20 historical gold workings are known within the tenement area along the N-S structural trends at an angle to the Springdale fault zone, generally hosted by sediments associated with intrusives or structurally controlled by quartz veining in sediments.
Figure 4: Springdale Project – located of historical Mine Workings (Source: from Cootamundra 1:250K Sheet Metallogenic Map (Geological Survey of NSW))
The area covered was considered prospective for intrusive related gold mineralisation. Other potential styles of mineralisation were thought to include structurally controlled gold mineralisation as well as intrusive related nickel, copper, tin and tungsten. Numerous stocks and dykes associated with acid volcanics were potentially hydrothermally altered and may have been gold mineralised targets.
Previous Exploration
Several companies searching for a variety of commodities have conduced exploration on the Springdale Project. Central West Exploration and Mining Syndicate completed reconnaissance mapping and geochemical & geophysical surveys (IP and magnetic) during 1969-1972.
During the 1980-1982 period, Alkane Exploration NL completed mapping, soil, stream sediment and rock chip sampling along with 4 diamond drilling holes at Merri Hill Prospect.
Getty Oil Development Corp and Little River Resources/CRA JV completed mine dump and rock chip sampling, IP and ground magnetic surveys, percussion drilling (30 holes) and Reverse Circulation (RC) drilling (3 holes) during the 1983-88 period.
In 1990, Newmont completed geological mapping and rock chip sampling. Paragon Gold conducted some mapping, magnetics surveys and rock sampling during 1992-93 period. Gold Mines of Australia completed soil and rock chip sampling, ground magnetic surveys. They also completed a drilling program of 37 air-core drilling and 9 RC drilling during the 1993-96 period. There is insufficient information at this time to determine the true width of the mineralisation.
Figure 5 shows the location of the drill hole collars.
Figure 5: Springdale Project – location of historical drill holes
Table 1 includes significant drilling results (>0.5 g/t Au). Details of the drill collar location and significant results are included in Appendix D of the Independent Geologists Report.
Table 1: Significant Drilling Results (>0.5 g/t Au)
Hole ID | MGA E | MGA N | Drill type | Depth | Azimuth | Dip | From m | To m | Au g/t | Year |
DDH1 | 563316 | 6181152 | Diamond | 67 | – | – | 65.9 | 66.2 | 2.60 | 1970 |
DDH2 | 563312 | 6181089 | Diamond | 70 | – | – | 50.9 | 51.3 | 1.22 | 1970 |
KD-1 | 565663 | 6180825 | Diamond | 95 | 90 | 55 | 65.8 | 69.7 | 2.19 | 1981 |
KD-2 | 565623 | 6180985 | Diamond | 128 | 90 | 50 | 105.0 | 105.7 | 0.90 | 1981 |
SD-4 | 563361 | 6181402 | RC | 51 | 91 | 60 | 16 | 20 | 0.60 | 1988 |
20 | 24 | 1.38 | ||||||||
24 | 28 | 0.54 | ||||||||
SD-5 | 563336 | 6181356 | RC | 50 | 89 | 60 | 20 | 24 | 1.44 | 1988 |
GPRC001 | 574897 | 6195620 | RC | 60 | 90 | 60 | 4 | 6 | 0.83 | 1993 |
SKP-004 | 565707 | 6180799 | RC | 35 | 250 | 60 | 34 | 35, EOH | 0.55 | 1993 |
SKP-005 | 565705 | 6180813 | RC | 55 | 250 | 60 | 34 | 36 | 2.24 | 1993 |
Proposed Exploration Program
The Springdale Project area is considered prospective for intrusive related gold mineralisation. The licence is dominated by a sequence of Silurian to Devonian siliciclastic sediments, including calcareous and carbonaceous units of the Combaning Formation. These sediments have been intruded by a complex suite of felsic to ultramafic intrusives. Numerous structures are interpreted to pass through the area, many of which are closely associated with historic gold workings.
The Springdale project represents a series of historical gold mines hosted in the Silurian sedimentary rocks in the southern Lachlan fold belt. More than 20 historical gold workings are known within the area, along with N-S trending structures at an angle to the Springdale fault zone, generally hosted by sediments in close proximity to intrusives.
Apart from intrusive related gold mineralisation, other potential styles of mineralisation are thought to include structurally controlled gold mineralisation as well as intrusive related nickel, copper, tin and tungsten mineralisation. Numerous stocks and dykes associated with acid volcanics were potentially hydrothermally altered and may have been gold mineralised targets.
The Au mineralisation is often associated with a halo of arsenic-rich pyrite and sericite (phyllic alteration) the pyrite halos can be detected with IP methods. It is recommended that the exploration plan includes mapping the broader alteration zones with modern IP methods and drill test IP anomalies to target bulk tonnage sedimentary hosted Au associated with broad pyrite (phyllic) alteration zones.
Springdale is also prospective for Cu / Au porphyry styles of mineralisation within the Ordovician Volcanic geological settings. In 1994, Gold Mines of Australia (NSW) Pty Ltd intersected 4m at 1.2 g/t Au at the Kangaroo Dick Prospect and intersected 10m at 1.3% Ni at the Merri Hill Prospect, located to the south of the Springdale Project. This highlights the exploration potential for the Springdale Project to also be prospective for nickel mineralisation.
The Company plans on undertaking additional reconnaissance exploration, soil geochemical sampling and geophysical surveys across the regional extent of the project area. Based on these results, the Company will undertake a regional reconnaissance exploration drilling campaign. In addition, the Company will complete some drilling along the main structures and zones of known gold mineralisation.
The purpose of the geophysical program such as Induced Polarisation (IP) surveys, will be to delineate and define potential copper-gold porphyry style targets which the Company can then systematically explore, similar to other exploration companies in the region.