Richard Williams, CEO of the Company, said: "The Trenares Target drill programme has been successful in demonstrating the presence of multiple zones of mineralisation in an area of the United Downs project that is underexplored, has never been mined and represents a compelling exploration target. The presence of high-grade tin and zinc warrants further follow-up exploration. Once we are in receipt of all remaining drill programme assays, we can evaluate the priority targets for follow up work."
The drill programme at United Downs project is now complete, with results pending for a further five holes drilled into the Mount Wellington, UD Lode, and United Mine targets still pending. In addition, eight drill holes for 2,501m were drilled at the Carn Brea South Target, located approximately 2km southeast of South Crofty mine site. Results for these drill holes will be released in due course.
The drill rig has now been moved to South Crofty where it will start an 8,000-12,000m drill programme designed to collect samples for metallurgical testwork as part of the South Crofty Feasibility Study leading to a construction decision for the South Crofty mine. This programme will involve three drill rigs testing the eastern, central, and western part of the mine complex. The other two drill rigs are expected to arrive at South Crofty over the next four to six weeks.
The geology at United Downs comprises metasediments (locally termed killas), which overlie an intrusive granite body. The historic mines within the area (United Mines, Consolidated Mines, Mount Wellington, and Wheal Jane) exploited copper, tin, zinc and silver mineralisation hosted entirely within killas.
The polymetallic mineralisation is primarily hosted in narrow, steeply dipping vein or lode structures, and consists of cassiterite (tin), chalcopyrite (copper) and sphalerite (zinc) with other copper minerals such as chalcocite and bornite occasionally present.
United Mines and Consolidated Mines, located 320m and 720m north, respectively, of the Trenares Target operated between the early 1700s and the 1870s, mining high-grade copper ores (reported grades of 7.5 per cent copper) to depths of up to 500m below surface.
The Mount Wellington and Wheal Jane mines exploited similar structures located along strike from the historic mining at United Downs, where tin, copper and zinc mineralisation were mined and processed until 1978 and 1991, respectively. Wheal Jane was mined to a depth of approximately 500m below surface whereas Mount Wellington only reached approximately 200m depth before closing. Mount Wellington is located within Cornish Metals' mineral rights and was still in mineralisation when the mine closed.
Drilling at United Downs has been performed by Priority Drilling Company Ltd using an Epiroc Christensen CT14 diamond drill rig. Mineralised zones were drilled in NQ (76mm) diameter) to recover a 48mm diameter drill core. Core recovery was greater than 95 per cent. The core was logged, split, and sampled by Cornish Metals personnel. The samples, comprising half core, were sent for assay at ALS Minerals, Loughrea, Ireland. Sample preparation involved crushing to 70 per cent less than 2mm, riffle split and pulverised to 85 per cent less than 75 microns. The analytical method used was X-ray fluorescence (XRF) following a lithium borate fusion. Samples were assayed for with this technique include copper, tin, tungsten, zinc and arsenic. A multi-element four-acid digestion ICP-AES analysis was also carried out to further characterise the mineralisation and alteration assemblages. Overlimit assays on silver were carried out using a three-acid digest and a HCl leach ICP AES analysis.
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