Challenger Exploration (ASX: CEL) has announced significant intersections from its initial 454 metres of rock-saw channel sampling along the main Humedo Adit at Colorado V and three additional drill holes from the Colorado V concession in Ecuador. The company said that the results confirm the potential for major gold porphyry discovery.
CEL reported 385 metres of mineralisation in the main Humedo Adit including 112 metres at 0.6 g/t AuEq and 52 metres at 0.7 g/t AuEq on the flank of the main Au-Cu soil Anomaly; 248 metres at 0.5 g/t AuEq including 114 metres at 0.7 g/t AuEq, from surface, in drillhole ZK16-2 located on the northwest flank of the main Au-Cu soil Anomaly; and 112 metres at 0.5 g/t AuEq within a zone of 454m at 0.3 g/t AuEq over the entire length of drillhole ZK0-4 located on the southern boundary of the main Au-Cu soil Anomaly.
Challenger said that the results are from the margins of regionally significant Au-Cu soil anomalies with grades now shown to increase towards the centre of the anomalies which are yet to be drill tested. The company said that the two main Au-Cu soil anomalies have the same geology, grades, and surface footprint as the Tier 1 Cangrejos Gold Project located five kilometres to the northeast.
CEL said that the recently acquired airborne magnetic data confirms these large Au-Cu anomalies are coincident with significant underlying magnetic anomalies indicative of porphyry systems.
Challenger said that all drill holes within the two main 1 kilometre long Au-Cu soil anomalies have returned significant mineralisation with drilling to test the centre of the anomalies early next year. The company said that the results confirm its strategy of large tonnage gold projects in Ecuador that will be carried by the Company’s high-grade Hualilan Gold project in Argentina.
Colorado V project
The Colorado V mining concession is located in Bellamaria, Santa Rosa, El Oro, Ecuador, and is held by Goldking Mining Company S.A. It is adjacent to El Guayabo concession to the north.
The Colorado V Tenement has the same geology as the Company’s existing El Guayabo Gold and Copper Project. Goldking had undertaken extensive and high-quality exploration which included a multi element soil geochemistry survey covering approximately 20 square kilometres, 21,500 metres of core drilling and a yet to be defined number of kilometres of underground exploration drives and workings. The core was moved to the Company’s core storage facility at the El Guayabo Gold and Copper Project for logging and sampling.
The mineralized zones on the Colorado V mining concession include Anomaly A, Anomaly B, and Anomaly C, of which the main Au-Cu soil anomalies are Anomaly A and Anomaly B.
The geological mapping was conducted along the main Humedo’s adit which is approximately 400 metres in length.
The main Humedo Adit is 430 metres long and provides access to a 500-metre northwest-southeast trend currently being exploited by small scale underground mining. The Main adit cuts the western flank of Anomaly A, the largest of a series of coincident gold, copper and molybdenum soil anomalies believed to represent porphyry targets.
The company had recently undertaken an initial 454 metres of rock-saw channel sampling along the main Humedo Adit at Colorado V.
The sampling was conducted during October 2020 using a rock saw to cut a continuous channel in the wall of the Adit, which was sampled, logged, and assayed in the same manner, and with the same QAQC standards, as drill core.
The company said that the channels are designed to provide a representative sample of the wall which is approximately the same size and weight as a drill core sample. CEL said that the assay results from these samples are expected to be able to be utilised in any future resource estimates.
The main Humedo Adit and the drill holes are located adjacent to a series of regionally significant gold and copper soil anomalies believed to be above intrusive porphyry-style targets. The Company’s recently acquired airborne magnetic data, which is currently being processed, confirms that these large Au-Cu soil anomalies are coincident with significant underlying magnetic anomalies indicative of porphyry systems.
The Humedo Adit, while located on the western flank of Anomaly A, is the nearest point sampled to the centre of Anomaly A, with the northern section (top) of the adit the closest to the centre of Anomaly A.
Challenger reported that the channel sampling was undertaken continuously from surface at the Humedo Mine adit entrance to 310 metres along the SW trending main Humedo Adit with another 146 metres sampled from the Western Drive located at the end of Humedo Adit from +430 to +576 metres.
Significant intersections from channel sampling
The company reported that high-grade results were reported from the channel sampling. Challenger said that the channel sampling in the Main adit, and new assays from historical drill core samples, returned significant ore grade intersections from surface down to 450 metres. Importantly, the results returned the highest grades closest to the centre of the main Au-Cu soil Anomaly A.
The company said that the main Humedo Adit returned 385 metres of mineralisation from the 456 metres rock saw sampled.
CEL said that the northern section of the adit returned 264 metres at 0.4 g/t AuEq (0.3 g.t gold, 2.1 g/t silver, 512 ppm copper, 9.4 ppm molybdenum) including 112 metres at 0.7 g/t AuEq (0.6 g.t gold, 2.7 g/t silver, 784 ppm copper, 9.4 ppm molybdenum) plus 32 metres at 0.3 g/t AuEq (0.2 g.t gold, 1.4 g/t silver, 366 ppm copper, 5.1 ppm molybdenum). This mineralisation is located at the western edge of the largest Au-Cu soil anomaly, Anomaly A.
The company said that the first 62 metres of the adit, which returned the highest grades of 62 metres at 0.8 g/t AuEq (0.6 g/t gold, 2.7 g/t silver, 848 ppm copper, 10.4 ppm molybdenum), is the nearest section of the Adit to the centre of Anomaly A.
CEL reported that the channel sampling of the Western Drive from the end of the main Humedo Adit returned 39.1 metres at 0.3 g/t AuEq (0.3 g.t gold, 2.3 g/t silver, 280 ppm copper, 4.5 ppm molybdenum) and 56 metres at 0.7 g/t AuEq (0.6 g.t gold, 1.8 g/t silver, 125 ppm copper, 3.0 ppm molybdenum).
The company said that this mineralisation is located well outside Anomaly A, is associated with antimony and bismuth, and has low associated copper and molybdenum similar to the main zone of mineralisation currently being exploited underground. This mineralisation is interpreted as an extension of the main Humedo Mine, which was intersected in drill hole ZK0-2 (151m @ at 0.9 g/t Au, 3.8 g/t Ag)a further 100 metres to the west along strike in an area of limited historical drilling.
Potential for major gold porphyry discovery
CEL said that the results confirm the potential for major gold porphyry discovery at Colorado V Gold Project. Management said that the results materially upgrade the main Au-Cu soil anomalies (Anomaly A and Anomaly B) as compelling drill targets with significant scale.
New assays from historical drill core samples
CEL has now reported new assays from historical drill core samples. The drill holes are from a series of 60 historical holes drilled by CEL’s farm-in partner at Colorado V, targeting extensions to narrow high-grade vein hosted gold mineralisation they are currently exploiting.
Drill hole ZK16-2 was collared to the north of Anomaly A and drilled south into the western margin of Anomaly A before tracking outside of the anomaly, the drill hole ZK10-1 was collared outside of the main Au-Cu soil anomaly A and drilled into the north-west corner of the anomaly, and the drill hole ZK0-4 was collared at the extreme southern edge of Anomaly A and drilled vertically
The company said that the hole ZK16-2 returned a broad zone of significant mineralisation of 248.3 metres at 0.5 g/t AuEq (0.3 g.t gold, 2.7 g/t silver, 686 ppm copper, 2.6 ppm molybdenum) including 114 metres at 0.7 g/t AuEq (0.5 g.t gold, 2.9 g/t silver, 926 ppm copper, 3.4 ppm molybdenum) with a higher-grade zone of 30.0 metres at 1.1 g/t AuEq (0.9 g.t gold, 3.6 g/t silver, 1157 ppm copper, 3.4 ppm molybdenum).
CEL reported that the drill hole ZK10-1 recorded two broad intercepts of 126m at 0.3 g/t AuEq from 25m and 115 metres at 0.3 g/t AuEq from 309m. The last 15 metres of the hole returned the highest grades recording 15 metres at 0.5 g/t AuEq, ending in mineralisation.
The company reported that the drill hole ZK0-4 intersected significant mineralisation over the entire length of the hole returning 454m at 0.3 g/t AuEq (0.2 g.t gold, 1.3 g/t silver, 399ppm copper, 5.9 ppm molybdenum) including 112m at 0.5 g/t AuEq (0.4 g.t gold, 1.9 g/t silver, 504 ppm copper, 7.6 ppm molybdenum).
Magnetic survey completed
The company said that 50 square kilometre airborne magnetic survey was completed in the first week of December and the preliminary Total Magnetic Intensity and Total Count radiometric grids have been received. The company said that it will have the magnetic data externally post-processed prior to interpretation. CEL said that the processed magnetic data will be combined with other geophysical data, geology and geochemistry to establish targets for initial drill testing by CEL.
Updates and next steps
The company said that the assays from a second phase of 340 metres of channel sampling in Humedo Mine, and the newly discovered Cuenca Mine (within Anomaly A), located 450 metres south-east of the Humedo Mine, are pending. CEL said that several additional historical drill holes have been logged, sampled, and submitted for assaying.
CEL Managing Director, Kris Knauer, said: “These results significantly upgrade our high-priority porphyry targets in Ecuador where historical drilling on the margins of significant gold-copper soil anomalies has encountered ore grade mineralisation from surface to 450 metres.
Grades are now confirmed to be improving towards the centres of these 1 kilometre long anomalies which remain undrilled. Additionally, our recently acquired magnetic data shows coincident magnetic anomalies indicative of porphyry systems.
This reinforces our strategy of a large scale bulk-gold project in Ecuador which is underwritten by our flagship, high-grade, Hualilan Gold project in Argentina which remains our primary focus.”