Aston Bay (TSX.V: BAY, FSE: 6AY, WKN: A2AUFP)and American West continue 2024 drill program at Storm project, providing additional evidence of the existence of an extensive, deeper copper horizon. This is still open at the edges and covers an area of more than ten square kilometres.
The three new holes, drilled approximately two kilometres apart, are designed to test the question of whether there is another deeper structure below the known copper mineralisation and, if so, how thick it is. These investigations were prompted by a significantly deeper hole drilled in 2023.
Drilling at Storm; Source: Aston Bay
It had reached a deeper copper horizon for the first time, so that the question of how large this deeper horizon is and which zones are of particular interest is now coming to the fore. The findings collected so far point to a positive answer to the questions raised, because all three deep boreholes intersected deeper copper sulphides and showed promising stratigraphy within the copper horizon.
The parallels to the Central African copper belt are considerable.
In September, Aston Bay Holdings reported that drill hole ST24-01 had intersected thick copper sulphides at 311 metres downhole, grading up to 3.7% copper. This result, together with the observation that drill hole ST24-02 in particular encountered large-volume mineralisation, highlights the lateral and vertical extent of the copper system at Storm. This increases the chance of having encountered stratabound, large-scale copper deposits similar to those found in the Central African Copperbelt. This further strengthens the evidence that significant copper grades will also be encountered at Storm at deeper levels.
The second drill hole in this series, ST24-02, was drilled as a diamond hole and designed to test the structure and stratigraphy in the southern areas of Storm in more detail. The hole reached a depth of 455 metres and immediately intersected a series of copper horizons. This is sulphide mineralisation that occurs over a total length of 98.6 metres.
ST24-02 is characterised by several thin higher-grade horizons that combine to give wide intervals of lower grade copper mineralisation. The overall package of rocks is variably fractured with copper sulphides present as both veins and fracture fill. The large volume of mineralisation indicates a significant mineralising event and its location at the centre of the Thunder and Corona graben block highlights the potential to discover economic mineralisation at depth.
Technical challenges result in third hole being suspended
Below the known mineralisation, hole ST24-03 at the Cirrus deposit targeted an electromagnetic anomaly measuring 1,300 metres by 500 metres. However, a section with a highly fissured zone caused difficulties shortly before the targeted zone was reached. To penetrate the frozen Arctic ground, salt must be added to the drilling fluid. This prevents the drill bit from freezing solid. However, the drilling fluid was lost in the heavily fissured zone. Since the drilling season is too far advanced and the required salt could no longer be delivered in time, the drilling was therefore suspended at this point. The hole expected to be completed in early 2025.
It makes sense to attempt to start drilling again next year and to complete the hole, because the targeted anomaly has both the characteristics of a mineralisation embedded in faults, as is the case with the Chinook type, but also has characteristics of a stratabound mineralisation. Such a mineralisation is encountered, for example, at the Cyclone deposit. Both these factors make the anomaly a very compelling target, justifying the execution of a second approach in 2025.
Two different observations determined the completed parts of the drill hole. Only minor copper sulfides were detected in the upper sections. However, when the fractured carbonate rock was reached at a greater depth, and thus an environment was reached that is generally considered to be a very favourable environment for the deposition of copper sulphides, copper levels also rose here. The drill hole thus remains a priority target for next year.
