TNM Drill Down: Top gold assays for the week Sept 2-9

Our TNM Drill Down feature highlights the top gold assays of the past week. Drill holes are ranked by gold grade x width, as identified by our sister company Mining Intelligence. 

Top gold assays for the week Sept. 2-9, 2022.

This week’s top three assays were all delivered by Australian-listed companies exploring for gold at home.

The top hole came from Catalyst Metals’ (ASX: CYL) Henty underground gold mine, located near Queenstown in northwestern Tasmania. 

Diamond drill hole Z22563 hit 8.7 metres of 129 grams gold per tonne starting from 45.6 metres depth for a grade x width of 1,122. The hole was drilled in the Darwin South zone, one of several zones (including the Mt Julia, Zone 96, Intermediate and Cradle zones) being targeted in a four-rig, underground drill program. 

The nearly completed A$7-million drill program will inform a resource update expected in September, and is part of Catalyst’s plan to increase production to 35,000 oz. gold annually and lower costs. In its most recent quarter, the mine produced 6,397 oz. at an all-in sustaining cost of A$2,100 per oz. 

Catalyst acquired Henty, which has produced 1.4 million oz. of gold at an averaged mined grade of 8.9 grams gold per tonne since mining began in 1996, in January 2021. Full year 2022 production (ended in June 2022) at Henty was 25,200 oz. Gold at a mined grade of 4 grams gold. 

Great Boulder Resources (ASX: GBR) had the week’s second-best hole at its Side Well advanced exploration project near the town of Meekatharra, in the northwestern corner of Western Australia state. 

Reverse-circulation drill hole 22MBR038 cut 15 metres of 35.8 grams gold per tonne from 88 metres for a grade x width of 537. The interval, which is interpreted as being close to true width, also included 6 metres of 83.58 grams gold. The hole was drilled at the large, high-grade Mulga Bill deposit, the main focus of drilling at the 132-sq.-km Side Well project. Mulga Bill, a 6-km north-south corridor of widespread intense alteration and gold mineralization, is located on the Meekatharra-Wydgee greenstone belt. The deposit is hosted within felsic to intermediate volcanics and volcaniclastics, which Great Boulder says is a new style of mineralization for the Meekatharra goldfield. 

Great Boulder noted that hole 22MBR038 extends the high-grade vein area at Mulga Bill 30 metres south, and cut the same vein that previously returned 5.9 metres of 39.37 grams gold from 84.3 metres and 6 metre of 24.33 grams gold from 132 metres. The main high-grade vein area at Mulga Bill has now been defined along 130 metres of strike length. 

Rounding out the top three was Aurumin Ltd., (ASX: AUN) which cut 352.8 metres of 1.5 grams gold per tonne from 267.2 metres depth in hole SNTMRD-22-003 (grade x width of 529) at the Two Mile Hill deposit at its Central Sandstone project. 

The hole, which continued in mineralization (145.2 metres of 0.5 gram gold) is the third from the current RC and  diamond drill program, started as an RC hole, but was drilled as a diamond drill hole below 121 metres depth. 

Located in Western Australia, near the township of Sandstone, 520 km northeast of Perth, the 112-sq.-km Central Sandstone project has existing infrastructure that includes a non-operating 500,000 tonne-per-year carbon-in-leach processing plant that was last used in 2010. 

Two Mile Hill hosts an underground inferred resource of 14.2 million tonnes grading 1.1 gram gold per tonne for 500,000 oz. Gold. The majority of the resource occurs within a tonalite intrusion, with mineralization also occuring within banded iron formation (BIF) beds, and within the basalts that host the tonalite intrusion. 

Aurumin’s 2022 drill program has also targeted the nearby Shillington BIF gold deposit. It expects to update its resource model by combining the two deposits as a single geological complex as it continues to advance Central Sandstone.