Tesoro Resources Limited (ASX: TSO) announced the intersection of multiple gold-bearing zones with best results of 111.50m @ 1.25g/t Au including 27.50m @ 3.57 g/t Au from the four diamond drill holes completed at Ternera prospect within the El Zorro Gold Project in Chile.
The company reported that assays were received for two infill and two extensional drill holes completed at the Ternera prospect – ZDDH00045, ZDDH00046, ZDDH00049, and ZDDH00054 further extending the drilled mineralised zone.
TSO said that all holes intersected multiple mineralised gold zones with significant results from holes ZDDH00049 and ZDDH0054 adding to the large-scale potential of El Zorro.
Important intercepts include 111.50m @ 1.25g/t Au from 124.00m from ZDDH00049 (Southern Extension); 19.00m @ 0.46g/t Au from 91.00m from ZDDH00054 (Northern Extension); 10.20m @ 1.07g/t Au from 36.00m from ZDDH00045 (Infill); and 21.40m @ 1.17g/t Au from 17.60m from ZDDH00046 (Infill).
The company said that the results confirm continuity of mineralisation 140m north of the main Ternera zone and extend the high-grade zone associated with the CC400, CC450, and CC500 fault zones an additional 70m south.
TSO said that the infill drilling confirms near surface continuity of gold mineralisation. Tesoro said that 41 holes were completed at El Zorro, for 11,241m, with assays outstanding for 23 holes.
The company said that the geophysics crew have commenced work on extensional Gradient Array Induced Polarisation (GAIP) survey targeting extensions to the NW and SE.
Tesoro said that drilling continues at the Ternera prospect with two diamond drill rigs operating 24 hours per day and given the growing scale, drilling is expected to continue into December 2020.
El Zorro project
The El Zorro Gold Project is Tesoro’s main focus and covers over 500km2 and is located 140km by road from the city Copiapo in Region III, northern Chile.
Historical mining by artisanal workers at El Zorro was limited and largely concentrated on early stage quartz veins in and around Ternera prospect within the El Zorro Tonalite.
Tesoro has classified the El Zorro Gold Project as being an Intrusive Related Gold (IRG) system and has affinities to the Tintina Province in North America.
Since commencing exploration Tesoro has expanded the know occurrence of gold mineralisation and host rocks outside of the Ternera Prospect and delineated multiple targets prospective for gold mineralisation.
The company said that it had identified Ternera as the first of five targets identified at El Zorro to be drilled. The company had completed 41 holes at El Zorro, for 11,241m, with assays outstanding for 23 holes.
Diamond drilling at Ternera
Tesoro said that it has completed four diamond drill holes at the Ternera prospect.
Extensional drill holes
TSO said that holes ZDDH00049 and ZDDH00054 were designed as step out holes to extend the drilled mineralised zone at Ternera.
Hole ZDDH00049 was designed to extend mineralisation associated with faults from the CC400 to CC500 to the south by approximately 70m, from previously reported hole ZDDH00031. Hole ZDDH00054 was designed to further test the northern extension of the Ternera GAIP chargeability anomaly extending the mineralised zone by approximately 140m to the north.
Infill drill holes
The company said that the holes ZDDH00045 and ZDDH00046 were infill holes designed to provide additional information for modelling and resource estimation. Holes ZDDH00045 and ZDDH00046 were both designed to test the near surface CC350-CC400 fault zones.
TSO said that all of the DD holes returned positive results, intersecting multiple gold bearing zones.
Multiple mineralised gold zones
The company announced that the assays received for two infill and two extensional drill holes have further extended the drilled mineralised zone.
Significant intercepts include the following.
ZDDH00049 (Southern Extension): 111.50m @ 1.25g/t Au from 124.00m including; 58.00m @ 2.04g/t Au from 124.00m including; 27.50m @ 3.57g/t Au from 154.00m including; 13.00m @ 5.32g/t Au from 159.00m including; 4.50m @ 3.07g/t Au from 231.00m.
ZDDH00054 (Northern Extension): 19.00m @ 0.46g/t Au from 91.00m including; 4.00m @ 1.48g/t Au from 104.00m; and 1.00m @ 8.75g/t Au from 280.00m.
ZDDH00045 (Infill): 10.20m @ 1.07g/t Au from 36.00m; and 6.70m @ 1.10g/t Au from 196.30m including; 1.50m @ 3.21g/t Au from 196.30m.
ZDDH00046 (Infill): 21.40m @ 1.17g/t Au from 17.60m including; 3.00m @ 5.71g/t Au from 28.00m.
The company said that the results from ZDDH00049 demonstrate the consistent continuity of grade and width of this wide mineralised zone. Tesoro said that from ZDDH00054, a broad low-grade intercept was returned associated with the extension of the CC500 fault zone, and multiple small, mineralised fault splays were also encountered which returned grades of up to 8.75 g/t. The company said that additional drilling is planned between holes ZDDH00054 and ZDDH00042 to delineate gold mineralisation in this zone, as well as further step out drilling to the north along the IP chargeable anomaly.
TSO said that the infill drill holes successfully delineated shallow mineralisation, and further drilling is required to test down dip and along strike.
IP survey update
Tesoro said that following the successful use of Induced Polarisation (IP) surveying to assist delineation of gold mineralisation at El Zorro, it has decided to extend the previously surveyed GAIP grid to the NW and SE.
The company said that the survey is designed to assist delineation of the southern extensions of the Ternera deposit, as well as assist identification of future drill targets over the Drone Hill prospect area to the north west.
TSO said that the contract survey crew have arrived on site and has commenced the extensional survey with results expected to become available in the next three weeks.
Updates and further work
TSO reported that a surface mapping and detailed trench sampling campaign has commenced at the Toro Gordo prospect to further define surface gold mineralisation associated with extensive quartz veining and alteration previously delineated. The company said that this work is scheduled to continue for a further three to four weeks with assay results from sampling expected in early 2021.
TSO reported that a program of screen fire assaying has commenced to assess the grade effect of coarse or nuggety gold within the Ternera deposit. The company said that the procedure is equivalent to assaying a large sample to extinction and averaging the results.
The company said that during drilling at Ternera, coarse visible gold was observed in multiple holes and where visible gold has been logged samples have been sent for additional analysis using a screen fire assay method.
The Company continues to drill at Ternera, with two diamond drill rigs operating 24 hours per day. TSO said that the mineralised footprint at Ternera continues to expand, with positive results from step out drilling and mineralisation remaining open in all directions.
Tesoto said that further work will be focused on drill testing the Ternera mineralisation and additional prospects as defined in the work program. TSO said that the core will be used for metallurgical testwork and resource modelling is planned.
Management comments
Tesoro Managing Director Zeff Reeves said: “Every hole drilled El Zorro continues to deliver quality gold results further adding to the scale of the Ternera deposit which now been drilled over a strike length in excess of 750m, a width so of up to 600m and is open at depth. We are yet to find the edges of the mineralisation and every hole adds additional scale. This indicates to us that we have a significant discovery at El Zorro.
The wide high-grade zone emerging to the south is particularly exciting and continues to exhibit a well defined wide, high grade zone, which is now continuous for over 300m and up to 100m wide and open in all directions. These new extensions provide additional infill drill targets that will be drilled over the coming months.”