The unique drill set-up and infrastructure requirements to allow drilling to occur on the salt crust surface of Lake Torrens has been a success. Following the completion of drill hole TD7, which was located approximately 1.5km from the shoreline of Lake Torrens and was drilled to a total depth of 858.6m, the drill rig and site infrastructure was safely demobilised and moved a further 7km east from Lake Torrens shoreline (western margin) for the commencement of drilling TD8.
Aeris executive chairman, Andre Labuschagne said that the drilling process has gone very well to date. "Whilst it is early days and logging and assays are still pending, we are very encouraged with what we have seen from this first hole. It is also pleasing that we have safely completed this first hole using the unique drill rig configuration."
Drill core from TD7 will be transported to Adelaide for sample preparation (core cutting) and assaying, with assay results expected in towards the end of April.
Drilling of TD8 commenced on the 23rd February and is the first drill hole to be drilled beyond 4km from the Lake Torrens shoreline.
On 27th February the drill hole intersected an unexpected aquifer at approximately 100m downhole, which resulted in artesian water flow. Drilling activities were suspended once the aquifer was intersected and remediation actions enacted to stop the flow of water reporting to the surface. The decision has been made to discontinue drilling activities at TD8.
The Torrens technical team, in conjunction with the site-based contractors, are reviewing all procedures and hazard mitigation strategies to incorporate the intersection of artesian aquifers in future drill holes. Once the documentation to incorporate the modified procedures/ processes has been completed, drilling will recommence.
The next drill hole (TD9) will be in close proximity to TD8 as the targeted deep gravity anomaly is still to be tested.
The Torrens Anomaly is a large regionally significant coincident magnetic and gravity anomaly with a footprint in excess 120km2.
Within the Torrens Project area, geophysical modelling/interpretation has identified 28 geophysical anomalies based on gravity and magnetic geophysical datasets. Limited drilling, totalling six drill holes between 1977 and 2008, defined a large magnetite dominant with lesser hematite alteration system interpreted to form the distal component of a large IOCG system. Zones of anomalous copper mineralisation (≥0.1% Cu) were intersected from several drill holes with the most significant mineralised zone associated with TD2 (246m @ 0.1% Cu).
