Sunstone Metals Ltd (ASX:STM) has defined a significant exploration target for the Limon gold-silver discovery within the Bramaderos Project in Ecuador, highlighting the scope for a substantial resource and a significant development.
The initial exploration target — just 10 months after the discovery was made — comprises the Limon ‘Central Shoot’, the surrounding mineralised area measuring 800 metres by 300 metres, and three of the additional six satellite targets outlined to date.
Limon's conceptual exploration target consists of 30 to 44 million tonnes at a grade of between 0.9 and 1.2 g/t gold equivalent, for between 900,000 and 1.7 million ounces gold equivalent (comprising gold and silver only).
The target extends from surface to depths of up to 400 metres below surface and is in addition to the existing 2.7 million ounce gold equivalent resource for Brama-Alba gold-copper-silver porphyry mineralisation, and to the 3.3 to 8.6 million ounce porphyry gold-copper-silver exploration target from Brama-Alba, Melonal and a small porphyry at Limon.
The Limon gold-silver discovery is classified as an intermediate sulphidation epithermal deposit (ISE). It is expected that multiple shoots will be discovered within the broad 1.7-kilometre x 700-metre Limon alteration system.
The excellent metallurgy from Limon has been confirmed with recoveries of more than 90% for both gold and silver.
Goal: a 10 million ounce gold district
Sunstone managing director Malcolm Norris said: “This initial exploration target highlights the scope for a substantial resource and a significant development at Limon.
“The total inventory is growing at Bramaderos, and we are moving towards our stated goal of a 10-million-ounce gold district.
“And it must be emphasised that Limon, and other areas of mineralisation at Bramaderos, are ideally located for a mining development.
“There is existing grid power (93% renewable), the Pan American Highway is within 3 kilometres of the gold-silver-copper deposits, the area is between 900-1,100 metres above sea level, and Ecuador has a clearly defined process for moving from exploration to development”.
Drilling for growth and resource conversion
Sunstone’s next steps include surface exploration at all targets to expand the gold-silver system and to define the next phase of drilling to upgrade the exploration target to a mineral resource estimate.
“We believe there is every potential for a staged development at Bramaderos with Limon being the higher grade, lower cost, first-off development that paves the way for a larger development across multiple porphyry deposits of gold, copper and silver. These options will be further assessed as we complete more drilling and infrastructure studies,” said Norris.