|
Deposit Synonyms
Mineral District
Deposit Summary
persistent quartz-iron oxide reef carrying copper mineralisation for recovery of ~175 tonne of hand picked ore. Host was tillite of the Emeroo Subgroup. Diamond drill hole identified oxidised lode at depth.
Deposit Description
SPRING CREEK, quartz-iron oxide reef with copper mineralisation discovered in 1860. A persistent lode horizon can be traced for a considerable distance south along strike. Traces of sporadic mineralisation can be followed along the western edge of Mt. Remarkable Range to approximately the same stratigraphic level as the Willowie Manganese Wads (mindep # 6292), ~5km to the south.
The Spring Creek Mine was worked from 1860-65 for 6.1 tonne ore. It was re-worked from 1865-74 (no production records), with activity ceased when the copper price fell. Records at the time indicate a quartz-iron oxide lode in the adit at 2m wide, with shoots and bunches of copper carbonate ore. Bulk samples taken returned values of 4.5-6.2%Cu. Mining recommenced in 1906-07 with the adit extended to 48.7m, with a 12m drive developed to the SW on a second 1.7m wide lode trend NE-SW, dip SE, and widening to 4.6m at the end of the drive. The lode was reported as a siliceous ironstone, with veins of copper carbonate, grades 4.5-8%Cu. Incomplete production records were for ~70 tonne sent to market at grades 5-15%Cu. Recovery of specimen native copper was a feature. The mine reopened from 1916-18 via further extension of the old workings. Sampling by a Government geologist returned values from 2.8–8.9%Cu. The operation folded when the pumps broke down and the mine flooded. Recorded production was ~101 tonne at 4-5%Cu. Total production from 1860-1918 is estimated at 175 tonne. The mine was subsequently used to augment the local water supply, with a pump installed in 1928. A 200,000 gallon tank was installed in 1935, with pumping rate logged as 3,000 gallons/hr. Main workings included an open cut with a 4.5m drive, and shaft to 13.7m, an adit to 48.8m with several drives, and a main shaft to 42.7m with drives, stopes, and winzes.
Regional geological setting is an EW-trending fault cutting the W limb of a regional anticline, with a NS-trending fold axis. Local controls to mineralisation are fault intersections hosting high grade shoots pitching south. Host rock is described as altered tillite and feldspathised sandstone to silicified slate. Detailed mapping by Australian Blue Metal describes host to mineralisation as thinly laminated siltstone of the Tapley Hill Formation overlain progressively west by reddish shale of probable Angepena Formation, and sandstone of the Wilmington Formation. Ore mineralogy is malachite and azurite at surface passing to cuprite, native copper, and minor chalcocite in a supergene profile.
From 1969-71 RMC Minerals Ltd completed IP, geochemistry, magnetics, 5 percussion holes and 3 diamond drill holes to identify a 21m breccia zone at 1.8%Cu being oxidised mineralisation. No primary sulphides were recorded, no resource size was estimated. Sampling of mine drives recorded up to 6.4m at 2.5 to 8.9%Cu. They concluded that mineralisation was largely restricted to a siltstone-quartzite contact within the zone of the major EW-trending fault zone. The source of a 730m long IP anomaly remained unexplained, but was thought to be possibly related to graphite and/or pyrite in the siltstone.
Drilling by Intex Pty Ltd in 1994 in hole SC 1.5W, located 8m west of the main adit identified 12.2m @ 0.06-1%Cu, & 0.1-0.3%Co from 39.6-51.8m. Host was steep W-dipping metasediment of the Tapley Hill Formation. A diamond hole located 96m to the west confirmed the depth extension of the Cu zone, though no analysis for Co was undertaken.
Archer Exploration from 2015 is exploring for extensions to the high grade copper mineralisation. Their sampling of the underground workings confirmed multiple high-grade copper bodies, within halos of lower grade mineralisation in the range 1-3%Cu. They describe a classic supergene copper profile of uppermost copper carbonate, passing to copper oxide and native copper, passing to secondary sulphides of chalcocite and covellite. No primary sulphides have been encountered.
Discovery Year
? 1860
Commodities
Copper, Cobalt
Ore Minerals
Aurichalcite, Azurite, Chalcocite, Copper, Covellite, Cuprite, Malachite, Rosasite
Gangue Minerals
Iron oxide (non specific), Psilomelane, Pyrite, Quartz, Selenite
|