Sunstone Metals Limited (ASX: STM) has announced a highly positive update from the surface sampling at the Espiritu epithermal gold-silver target within its Bramaderos Gold-Copper Project in Ecuador.
The company reported that individual surface rock chip samples returned up to 11.6g/t gold and 2,960g/t silver.
STM said that Espiritu outlined over an 800m strike with multiple interpreted lodes. The company noted that the mapping of the distribution of clay alteration, quartz veining, barite, and metal values (gold-silver-lead-zinc-copper) indicates multiple parallel lodes.
Sunstone Metals announced that further sampling, trenching and mapping followed by drilling will take place as soon as Ecuador’s COVID-19 restrictions allow.
The Bramaderos project is centred approximately 69km west-southwest of the provincial capital city of Loja, 213km south-southeast of the coastal city of Guayaquil and 460km south-southwest of Quito.
Sunstone owns an 87.5% interest on the Bramaderos project with Cornerstone Capital Resources holding 12.5%.
Historical exploration results from drilling at Bramaderos together with recent exploration by Sunstone and joint venture partner Cornerstone Capital Resources indicate multiple fertile mineralised systems with significant discovery potential.
The exploration by other parties has included stream sediment surveys, geological mapping, rock chip sampling (888 samples) and grid-based soil sampling (1324 samples), trenching and channel sampling (17 trenches), ground magnetic surveys (31 line kilometres), electrical IP surveys and diamond drilling (10426m).
The project’s impotent prospects include Bramaderos Main prospect, Limon porphyry prospect, and the West Zone epithermal breccia prospect.
Now, Espiritu epithermal gold-silver target has been developed based on soil geochemical results and structural interpretations from field mapping and detailed ground magnetic data. No significant historical exploration has been undertaken in the Espiritu target area.
Exploration at Bramaderos
The company had undertaken exploration at Bramaderos prior to the temporary suspension of activities in Ecuador due to the Covid-19 pandemic.
The exploration has included geological mapping, surface rock chip sampling and some trenching to test outcropping mineralisation.
High-grade surface samples
STM announced that results have now been received from exploration. The results include high gold and silver assays from rock chip samples of quartz-barite veining associated with argillic alteration.
STM said that individual surface rock chip samples returned up to 11.6g/t gold and 2,960g/t silver. The rock chip assay data from Espiritu target is as below.
The company said that other samples are highly anomalous in epithermal related pathfinder elements such as lead, zinc, and copper.
It may be noted that these related elements can be detected using handheld XRF analysis which provides a guide for further detailed sampling and laboratory analysis.
The company reported that the Espiritu trench, ES-01, is partially complete and some samples are awaiting analysis at the laboratory. The company said that the handheld XRF analyses for zinc are used as a guide only to identify areas of alteration with the potential to host gold and silver, although this will only be confirmed once laboratory assays are completed.
Multiple parallel lodes
STM reported that the data so far suggests a north-north-east trend to the anomalous gold and pathfinder elements and this trend corresponds with linear breaks in the ground magnetic imagery.
The company said that an 800m strike extent to mineralisation has been defined by work to date and this could double to 1,600m based on early stage reconnaissance which has identified scattered gold anomalous samples along the north-north-east trend.
Sunstone said that this will be followed up once field work resumes.
Updates and next steps
The company announced that Exploration activities at the Bramaderos Project have been temporarily suspended in line with the COVID-19 directives of the Ecuadorian government.
Sunstone reported that it is maintaining communication with all employees and stakeholders in Ecuador. STM said that the desktop activities, primarily in Australia, are ongoing as data is being interpreted to move target areas towards being drill-ready when the suspensions are lifted.
Sunstone MD Malcolm Norris said: “These are outstanding results. Espiritu sits within the previously defined ‘epithermal corridor’ that extends to the south-west where it incorporates the 2 million-ounce epithermal Dynasty Goldfield.
In light of these high-grades and the extensive strike length, we will resume sampling and trenching as soon as possible with a view to drilling at Espiritu at the first opportunity.”