Gateway Mining has smashed out a spectacular hit in the first-ever fresh rock test of its recently discovered Cowza prospect, part of the company’s Yandal gold project 85km northeast of Wiluna in WA. The drill bit intersected a 41-metre zone of high-grade primary gold mineralisation, confirming it is onto a major new discovery.

The company’s first reverse circulation (RC) drilling of Cowza delivered the 41m intercept grading an impressive two grams per tonne (g/t) gold from 104m downhole depth, including a richer, high-grade 9-metre zone assaying a stellar 7.5g/t gold from 105m.

The result is a powerful validation of Gateway’s exploration model. The company’s previous systematic scout aircore drilling had defined a 4.5-kilometre-long stretch of continuous gold mineralisation in the shallower oxide zone, but this is the first time drilling has hammered deeper into the underlying fresh rock.

Notably, the discovery hole was plunged directly beneath a previous aircore intercept that returned 16m at 1.3g/t gold, including an 8-metre core at 1.9g/t gold. Management says the relationship between the shallow aircore hit in the interpreted oxidised saprolite zone and the deeper, high-grade primary mineralisation provides a clear exploration template for what might lie beneath numerous similar aircore results that remain untested along the 4.5km north-south trending structure.

A second RC hole, drilled 2km north of the headline hit, has also bolstered confidence in the system’s scale potential. While the hole missed the main target after being collared too far east, it still returned a broad 52m anomalous zone grading 0.3g/t gold from 44m.

Gateway says that result confirms the fresh rock system remains fertile and extends for at least another 2km to the north of the headline hole. The company says it’s already planning follow-up drilling to test the main structure a short distance west of the original hole to see if it can land on target the second time around.

The first RC test of Cowza has delivered exactly the sort of result we were hoping this large-scale gold system was capable of producing. Today’s result is the first effective test of that interpretation in fresh rock – and 41 metres at 2.0g/t Au, including a coherent high-grade core of 9 metres at 7.5g/t Au – is an outstanding validation of the team’s targeting.

The Cowza discovery is just one piece of a much larger jigsaw that Gateway is piecing together. The prospect forms part of an emerging gold corridor that also includes the 1.5km-long Celia South prospect, 4.5km north of Cowza and the recently-drilled 7km-long Ward trend 6km south of Cowza, representing a combined known mineralised strike of more than 13km on the same geological contact. If the intervening thinly-tested 6km of ground between Ward and Cowza also comes up with the goods in future drilling, the total mineralised strike could potentially blow out to a massive 19km.

The structural key underpinning this alignment of Gateway’s prospects – which also include its Dusk ‘til Dawn gold camp, the Horse Well gold camp, and its Great Western deposit – is the regional-scale Celia Shear, sometimes referred to as the Celia Lineament, a major, deeply penetrating structure located in the Eastern Goldfields super-terrane of WA’s Archean Yilgarn Craton.

The Celia Lineament is confirmed to be a crustal-scale structure. Deep seismic reflection profiling across the northeastern Yilgarn reveals that the Celia Fault cuts entirely through the upper and middle Archean crust. It acts as a primary, steeply dipping conduit connecting the upper mantle directly to upper-crustal geological architecture.

Because it transects the entire crust, the lineament serves as a macro-scale structural corridor that has historically funnelled deeply derived hydrothermal magmas and mineralising fluids, creating numerous highly productive gold systems throughout its extensive area of influence. This area includes the Yandal greenstone belt, a richly endowed piece of real estate that hosts a string of multi-million-ounce gold deposits, including the nearby Jundee, Bronzewing and Darlot mines.

The total length of the continuous corridor is of the order of 250 to 300 kilometres. It maps as a prominent, north-northwest-trending structural zone on regional aeromagnetic surveys. Within local segments such as the Yandal gold project, distinct targets including Cowza and Ward alone account for between 7km and 13km of near-continuous gold-mineralised strike.

The company believes historical drilling in the district has largely missed the main prize by focusing on secondary footwall structures, leaving the primary mineralised corridor almost entirely untested by deeper RC and diamond drilling until now.

With RC drilling ongoing at Cowza and diamond rigs scheduled to arrive on site later this month, Gateway appears well-positioned to build on its initial success. The company has also recently bolstered its war chest, liquidating some of its portfolio of securities to generate an additional $8.23 million in cash to underpin its revitalised exploration charge in light of its recent new discoveries.

With a 13km-long mineralised corridor now firmly in its sights and its first fresh rock test delivering a home run, Gateway will be looking to see if its new discovery has the legs to join the ranks of the other giants in the Yandal belt.

Is your ASX-listed company doing something interesting? Contact: [email protected]

Get the latest news from thewest.com.au in your inbox.

Sign up for our emails