The Doradilla Project represents a large and strategic tin project with excellent potential for associated copper, silver, bismuth, indium and zinc mineralisation. The known mineralisation is recorded within a skarn horizon which has an extensive strike length of 16 km (the ‘DMK Line’).
The regional geology of the area is not entirely clear but it is apparent that the area contains a major crustal suture representing the break between the Lachlan and Thompson Orogens. Recent work by the NSW Geological Survey demonstrates that the mineralising intrusives for the area are Triassic aged (235 Ma) and have similar age and chemistry to the major tin granites in the New England region such as the Mole Granite.
Previous exploration has focussed heavily on the tin content of the DMK Line, which comprises zones of oxide, supergene and primary tin mineralisation. Only part of the DMK Line has been evaluated, and the potential exists for additional resources. In addition, aeromagnetic features indicate the potential for other skarn horizons, parallel to the DMK line, which remain untested.
Tin exploration at Doradilla ceased in 1990 due to depressed tin prices combined with unsatisfactory metallurgical recoveries in the primary tin-silicate zone. YTC’s strategic partner, Yunnan Tin Company Group, successfully mine and process similar tin-silicate style tin mineralisation in their deposits in China.
In addition to tin, the Doradilla Project also represents a strong exploration target for nickel, copper, silver, bismuth, zinc and indium. In particular, the supergene tin- laterite deposits currently identified at 3KEL & Midway have the potential to contain economic levels of copper and zinc mineralisation based on the few holes that have been assayed for these metals. A considerable amount of previous drilling was assayed for tin only, with no systematic exploration carried out for any other metal.
Aurelia Metals has secured the right to earn 70% of the Doradilla Project from Templar Resources, a wholly owned subsidiary of Goldminco Corporation Ltd (‘Goldminco’ TSXV: GCP) by spending $1.5m over 5 years.
Drilling by YTC Resources has confirmed the tin laterite mineralisation at the 3KEL deposit is also rich in indium, bismuth, copper and zinc. Significant results include:
|Hole||From (m)||To (m)||Interval (m)||Sn %||Cu %||Zn %||Bi ppm||In ppm||Comments|
|3KAC004||6||46||40||1.56||0.56||0.38||117||Mineralised to end of hole (46m)|
|3KAC011||10||45||35||1.24||0.11||0.39||264||41||Mineralised to end of hole (45m)|
|3KAC014||16||52||36||0.91||0.29||0.58||522||34||Mineralised to end of hole (52m)|
Combined Resource:7.81Mt @ 0.28% Sn (at a cut-off grade of 0.1% Sn) for 22.3kt of contained tin
A summary of the Inferred Resources is presented below:
|Sn cut-off||Mt||% Sn||Mt||% Sn|
Nickel Sulphide Exploration
Areomagnetics has identified a number of ultramafic trends, where limited historic drilling identified broad intervals of nickel sulphide “skarn” mineralisation of the ‘Avebury’ type.
Significant results from previous explorers include:
|DR1||64m @ 0.23% Ni||North Broken Hill||1972|
|DBT-1||25m @ 0.13% Ni||Shell Minerals||1981|
|NDW-P88||2m @ 1.13% Ni||Seltrust Mining||1981|
A programme of aircore holes were designed to drill through the deep (+70m) laterite weathering profiles and terminate on weathered ultramafic bedrock. The strongest bedrock results for nickel were followed up by diamond drilling to define the nickel sulphide mineralisation below the base of weathering. Significant aircore results include:
|Hole||From (m)||To (m)||Interval (m)||Ni %||Co ppm|
Follow up diamond drilling produced anomalous sulphide based intercepts such as:
|Hole||From (m)||To (m)||Interval (m)||Ni %||Co ppm||Cu ppm||Sn ppm|
To the north of the DMK Line a series altered and mineralised quartz porphyry dykes outcrop in the vicinity of the Doradilla Copper Mine. YTC drilling has demonstrated broad low grade tin and zinc mineralisation as seen in hole DCMD001.
|Hole||From (m)||To (m)||Interval (m)||Zn ppm||Pb ppm||Sn ppm||Comments|
|DCMD001||133||159||26||3664||689||275||Mineralised to end of hole (159m)|
|Hole||From (m)||To (m)||Interval (m)||Sn ppm||Cu ppm||Pb ppm||Zn ppm||Bi ppm||Ag ppm|
The lode runs parallel to a larger, mineralising quartz porphyry intrusion, and is open both at depth and south along strike.