Tesoro reports exceptional gold assays from first drill hole at El Zorro

Tesoro Resources Limited (ASX: TSO) has announced a highly encouraging update from the ongoing initial drill program at its El Zorro Gold Project, Chile.

The company reported that outstanding high-grade gold results have been received from the upper part of the first drill hole at EL Zorro. The remainder of assays expected within the next two weeks.

The company said that gold grades are increasing with depth, with last assay received is mineralised (1.21g/t Au). Tesoro said that it is awaiting assays from 206.22m to 287.65m (EOH), contains visual alteration and sheeted veining associated with gold mineralisation.

Tesoro said that drilling has intersected multiple zones of gold mineralisation returning thick high-grade results including 23.0m @ 7.20 g/t from 183.22m including 15.0m @ 10.82 g/t from 190.00m, 5.3m @ 25.31 g/t from 197.00m, and 2.3m @ 46.41 g/t from 200m.

The company said that the two main gold zones intercepted project to the surface and have also been intersected at shallower depths.

TSO said that initial assays were received for sampling between 0m and 206.22m, awaiting further results from 206.22m to 287.65m (EOH ). The company said that these results and earlier drilling indicate potential for significant gold deposit at El Zorro.

Tesoro announced that 3 holes of a planned 10 hole program have been completed, with assays expected in the coming weeks. Tesoro is currently drilling ZDDH00020 and assay results from district sampling are pending.

El Zorro project

The El Zorro Gold project is located 140km by road from the city Copiapo in Region 3 in northern Chile.

Coeur d’Alene Mines Corporation (CDE) had completed exploration between April 1990 and January 1993 including drilling and excavation of several adits as part of its exploration and assessment program.

Tesoro has previously drilled 16 diamond drill holes at El Zorro, delineating a large gold system with all holes intersecting gold mineralisation and multiple 100g/m intercepts reported from the Coquetas target at El Zorro.

New drill program at El Zorro

Tesoro had commenced a new drilling program on 7 February 2020, with an initial 10 diamond drill holes planned to extend the Coquetas drilled mineralised zone from 350m of strike to over 800m of strike and up to 300m depth.

The company said that the first hole of the program, ZDDH00017 was completed to a depth of 287.65m with zones up to 65.00m wide (downhole width) of the EZT being encountered which has been subject to intense sheeted veining and alteration. Two zones of gold mineralisation have so far been intercepted in the hole.

A new, previously unknown, body of the EZT was encountered from 49.55m to 75.10m downhole with sheeted veining and trace visible gold at 57.70m.

High-grade results

Tesoro reported that this new zone has returned positive assay results with a broad zone of 30.00m @ 0.94 g/t Au being returned from 44.00m. Within that zone two higher grade intervals were returned of 3.00m @ 4.27g/t Au from 44.00m and 4.00m @ 4.26g/t Au from 70.00m.

The lower and main mineralised zone intercepted has to date returned results of 23m at 7.2 grams per tonne Au from 183.22m, including 15m at 10.82g/t from 190m, 5.3m at 25.31g/t gold from 197m, and 2.3m at 46.41g/t gold from 200m.

The company said that this lower zone of mineralisation remains open (final assay in reported intercept returned 1.21 g/t Au) with assays yet to be received from 206.22m to 287.65m (EOH). Assays are expected to be received for samples from 206.22m onwards within the next two weeks.

Visible gold

The company said that visible gold has also been observed in strongly brecciated sediments and associated silica alteration at 202.30m down hole.

TSO said that strongly altered EZT and associated intense sheeted veining has been logged from 206.22m to 231.50m. It should be noted that the observation of visible gold is by visual inspection of the core sample only and the samples are yet to be assayed or analysed to determine the actual gold content.

Drilling ongoing

The company reported that the El Zorro drilling continues. To date three drill holes have been completed of the current program at El Zorro.

TSO said that all holes have encountered zones of altered El Zorro Tonalite and associated sheeted veining and brecciation of between 15m and 55m down hole width.

Currently, hole ZDDH00020 is being drilled which is designed to extend the continuation of the El Zorro tonalite to the north by approximately 250m to give an overall strike of drilled gold mineralisation of approximately 800m.

Next steps

The company reported that further work will be focused on drill testing the Coquetas mineralisation and additional prospects as defined in the work program. Core will be used for metallurgical testwork and resource modelling is planned.

Management comments

Tesoro Managing Director Zeff Reeves said: “These assay results are exceptional and are to date the best gold results we have encountered in drilling at EL Zorro.

The wide, high-grade nature of the results received so far demonstrate the huge potential El Zorro has to host a significant gold deposit and confirms our geological model of multiple stacked gold mineralised zones that are increasing in grade as they go deeper.

We have now completed three holes of the current program and have stepped to the north in order to extend the current drilled mineralised zone by an additional 250m from where we are intersecting the host El Zorro Tonalite.”

Written By Jonathan Norris
Jonathan is a founder of Mining.com.au and has been covering the resources industry since 2018. With over 17 years experience in print, broadcast and online media, Jonathan has seen first hand the transformative effect of online niche media.