Exploration was focused on establishing the characteristics of airborne radiometric anomalies and the uranium potential of breccia pipes in the region.
The main outcomes include the recognition of a large-scale geochemical alteration system in the northern part of the company's wholly owned Karns tenement, which directly mirrors an intense airborne radiometric anomaly.
Toro identified up to 280 ppm U3O8 and 1360 ppm Cu in rockchips of quartz sandstone that is elsewhere chemically 'bland', along with coincident anomalous Ag, As and Pd up to 10 times background.
Another plus for Toro is that the Running Creek-Stanton breccia pipes also show anomalous uranium at surface associated with copper mineralisation suggesting a genetic connection to the stratigraphically higher Karns system.
McArthur Basin commonalities with the Arizona Strip 'remarkable'
Toro originally applied for the Karns (EL27429), Running Creek (EL28567) and Selby tenements (ELA29636) (main picture) due to the geological similarity to the Arizona Strip in the U.S., where uranium has been mined from multi-commodity breccia pipes for over 50 years.
The individual deposits of the Arizona Strip, whilst relatively small tonnage at less than10 Mlb U3O8, are high grade (>0.5% U3O8) and occur in a dense cluster that is able to support sustainable mining operations.
Toro believes there is a high-probability of similar targets in the McArthur Basin because breccia pipe clusters are already well known in the region (e.g., Redbank, Running Creek and Stanton pipe sets;) and have supported copper mining over the last 20 years.
The company also said that the geological and geochemical commonalities with the Arizona Strip are remarkable.
Toro flew detailed 100m-spaced magnetics and radiometrics over Karns in 2011, highlighting a number of large high-amplitude anomalies in the total count and uranium channels. These anomalies also dominate the regional datasets.
Toro is well-funded after earlier in the month securing A$12 million in funding through a convertible debt facility from Macquarie Bank, increasing the company's available working capital to A$19.5 million.
Toro proposes to undertake further soil and rockchips sampling at Karns and, when granted, the Selby tenement.
Ground electromagnetics has been used successfully in the Arizona Strip to identify individual breccia pipes under cover and Toro believes it will also be successful in the McArthur Basin in defining drill targets.
The development of further geophysics and an initial reconnaissance drilling program will be considered after this work.
Toro's Methodology and Results
During August 2012, Toro collected 32 rockchip, 70 lag and 112 multi-fraction soil samples along orientation lines on the Karns and Running Creek tenements.
The samples were submitted to ALS Laboratories for various digestions and chemical analyses with results from rockchip samples showing that U, Cu, Ag, As and Pd are consistently elevated within a large high-amplitude radiometric anomaly overlying the exposed basal sandstone of the Karns Dolomite in Toro‟s Karns tenement
Anomalous samples were collected over a stratigraphic thickness exceeding 10m. These results are considered extremely anomalous, as beyond the radiometric anomaly this sandstone has a uniform background range of only 1-5ppm U3O8 and 5-10ppm Cu, consistent with oxidised sandstones globally.
Rockchips also indicate that the same element suite is anomalous at the upper margins of breccia pipes sampled on Toro‟s Running Creek tenement (Stout, Saltlick and Felix). This suggests a close genetic connection to the stratigraphically-higher Karns system.
Toro said that the distribution of anomalous uranium and other pathfinder elements in rockchips and soil samples at Karns faithfully mirrors the spatial signature of the airborne radiometrics.
The company is therefore confident that the large (11 square kilometres) radiometric anomaly in the northern part of the Karns tenement reflects a broad alteration halo associated with breccia pipes in the underlying fertile Gold Creek Volcanics.
Based on the physical dimensions and concentration of uranium in rockchips, the alteration halo has a substantial inventory of uranium in itself, more than sufficient to potentially promote formation of economic uranium mineralisation.
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