Coeur adding Crown ounces may yield more district action

Standing on the drill pad where Coeur Mining discovered C-Horst in April 2020 puts one at the heart of the action. Less than 100m to the north is a drill rig on Corvus Gold's Lynnda Strip target, although it doesn't appear to be active. A few hundred metres beyond that there is an active rig on AngloGold Ashanti's ground at a target called Merlin. And there is certainly some geological magic at play given that a few hundred metres down the track to get here is Corvus's Mother Lode deposit, which extends onto Coeur ground.With AngloGold having put a long-anticipated bid on the table for Corvus in July, Coeur has been diligently drilling to add ounces at its Crown property which includes C-Horst, which means the end game for this area has yet to come.The magic in this area of the Walker Lane Trend appears to be the confluence of two regional structures which are believed to control mineralisation in the area: the Fluorspar Canyon Fault, the main east-west fault along which Coeur's Daisy, Secret Pass and SNA deposits are aligned and which then heads north to where C-Horst is. There is also the Bare Mountain Fault which runs north-south from Coeur's Sterling deposit 5km to the south and also into C-Horst. View towards C-Horst (right) from Mother Lode (foreground) with Silicon (left background) Coeur's C-Horst discovery returned an intercept of 97.5m grading 1.4 grams per tonne gold. It led Corvus to drill along its 300-foot wide Lynnda Strip area immediately to the north and Corvus's success in returning intercepts such as 185m grading 0.82g/t including 14.6m grading 3.4g/t resulted in AngloGold Ashanti increasing its drilling efforts in the area. This was perhaps ultimately instrumental in the major making a bid for Corvus in July.Activity in the area could continue to increase in the coming months, with Coeur seeking Bureau of Land Management approval to allow it to drill more holes in the Crown Block, to continue to infill and expand the four mineralised zones it has there. Crown is the company's only greenfield exploration drilling programme and one that has been growing. Coeur doubled its drilling programme at Crown this year to about 61,000m compared with 2020.The original plan of operations saw drilling focus on the Daisy, Secret Pass and SNA areas to corroborate and expand on the estimated resources the company obtained from Northern Empire via its October 2018 acquisition. All the deposits at Crown are potentially open-pittable and host heap leachable oxides. Coeur only reports a global resource for Sterling/Crown, identified as Sterling, which at the end of 2020 stood at 28.9 million tonnes grading 0.8g/t for 903,000oz.When Coeur acquired Sterling from Northern Empire it came with resources of 11.1 million tonnes grading 0.93g/t at Secret Pass, 5.4Mt grading 1.34g/t at Daisy and 3.9Mt grading 1.03g/t at SNA at a 0.3 grams per tonne cut-off.However, Coeur's Great Basin exploration director Joey Wilkins says the Crown area poses quite the geological puzzle. "I don't know of anywhere else where there are so many deposits so close together and so different. SNA is different from Mother Lode. Mother Lode is different from C-Horst and [AngloGold Ashanti's] Silicon is different again," he told Mining Journal during a site visit. A drill rig on Corvus Gold's Lynnda Strip viewed from the first C-Horst drill pad The gold deposits are sediment-hosted, controlled by the above-mentioned faults and are located in multiple levels of stratigraphy from Neo-Proterozoic to Miocene age with multiple pulses of mineralisation from 8 to 14 million years ago. Gold was localised by structures and structural intersections, or by intrusive activity. The target mineralisation style at Crown is disseminated, oxide-gold hosted in Cambrian to Tertiary rocks, located near the Fluorspar Canyon Fault. "We are in sediment-hosted gold deposits, not Carlin style. It is about finding the right relationship between different lithologies and structure," said Wilkins - no easy task given that in some areas older rocks have been thrust over younger rocks.Coeur aims to continue to build the resources to a meaningful amount of ounces which would provide it with several options for the project's future trajectory including bringing them into production itself or exploring some kind of mutually beneficial arrangement with AngloGold Ashanti, assuming of course, that AngloGold is successful in acquiring Corvus. Coeur could be getting close to a meaningful number of ounces given how its drilling has grown the mineralised footprint at Daisy and with the C-Horst discovery, which has not been included in any previous resource estimate. With the company expecting acceptance of its amended plan of operations in the coming months, it is possible the company will be able to update its resource early in 2022.The company is still drilling at Daisy where it is stepping out to the southwest and southeast and where it believes it will continue to add ounces. But C-Horst is the area it is most intent on adding to. Firstly, because it is a new discovery that it wants to flesh out; secondly, because this is where the two faults that control mineralisation in the district come together and thirdly, all the drilling and merger activity of its neighbours mean it is a hot target.Coeur also sees potential in the area between C-Horst and Mother Lode, including Pipeline Gulch, which hasn't seen a lot of historical drilling. C-Horst was a blind discovery where drilling targeted a gravity anomaly. Much of the area between it and Mother Lode is under geological cover and so the company is using various exploration techniques to try and identify a signature for C-Horst and which may be able to shed light on where more gold may be found towards Mother Lode.Crown looks like it could be a jewel in a reemerging gold district.

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