Great Panther’s Tucano gold mine was acquired in March 2019, and the company conducted 17 400 m of exploration drilling through the balance of 2019.
Concurrent with the drill programme, an evaluation of Tucano's extensive land package was initiated, and is still ongoing. Exploration is divided into ‘near-mine’ and ‘regional’ categories, with a total of US$6.6 million (55 000 metres) budgeted for 2020.
Jeffrey Mason, interim President and CEO, stated: "With a three-fold increase in drilling metres planned for 2020, the company is working to capitalise on Tucano's exploration potential […] Great Panther has identified near-mine targets that could lead to the development of new mineralised zones, and is prioritising prospects for new discoveries farther afield. In addition, with the current gold price well above the prices used in the historic pit shell designs, opportunities to expand the existing pits are being analysed."
Near mine exploration
An important consideration for near-mine exploration is the distinction between oxide ore and sulphide ore (fresh rock) in that historic production at the mine was focused on the oxide ore due to mill processing constraints. The completion of a plant upgrade in 2019 enabled the processing of sulphide ore, achieving gold recoveries of about 92%, and opens up the depth extensions for evaluation and exploration. Furthermore, current gold price levels provide the potential to widen and deepen some open pits, and delineation drilling is being undertaken between the current pit outlines and proposed deeper pit shells. The 2020 near mine exploration program will consist of 10 000 m of reverse circulation (RC) and 18 000 m of diamond core drilling (DD). The following describes the plans for individual target areas.
The four TAP AB pits are entirely in oxide ore, and are considered to have expansion potential. Secondary mineralised zones in the footwall (Carbonate Lodes) and hanging wall (NEO and NEO North Lodes) are to be drilled in more detail as they provide potential to reduce strip ratios and support a deeper pit. A combined 9000 m of RC and DD is planned for 2020 to better define these zones. Recent intersections below the currently scheduled US$1250/oz pit shell include good grades and widths and, in conjunction with a higher gold price, justify deepening the pits, wherein gold grades increase.
Torres / TAP AB South
A total of 11 000 m of RC and DD drilling is planned for 2020 to test the southern extension of the AB1 zone adjacent to the existing pit. This area is located at the structural intersection of the NW-SE trending 'D' zones and the main North-South mine trend, and is considered to be a favourable geological setting for mineralisation.
Urucum East Pit
An exploration report has been filed and accepted by the Agência Nacional de Mineração (Brazilian Mines Ministry), and Great Panther expects the issuance of an environmental permit and the granting of a mine operating concession in 2020. The current resources are based on near surface material and 4500 m of additional RC and DD drilling is planned in 2020 to prove up the deeper continuation of the ore.
Urucum North Pit and Underground
Diamond drilling in 2019 was completed just below the existing pit floor in order to better define mineralisation for the purposes of targeting a deeper pit. In contrast, the 3500 m 2020 infill drilling program will target the upper Central Lode for underground potential, and will be based on an improved understanding of the structural controls of higher-grade ore shoots as defined by the 2016 Prefeasibility Study (PFS). The Central Lode lies approximately 100 - 150 m below the existing pit floor, and the South Lodes 1 and 2 lie 100 - 200 m below that horizon. Urucum North has the advantage of good ground conditions in fresh rock that could allow reasonable development rates to optimise underground pre-production costs and time.
URSO / TAP AB3 East
The drill program would seek to extend gold mineralisation to depth along a 500 m strike length, as good grades have been intercepted at depths of 180 metres in oxide material. A further 5700 m for URSO / TAP AB3 East (incremental to the current planned 55 000 m for the entire Tucano program) of RC and DD is being evaluated for 2020 and, if warranted, deeper drilling could ultimately test the underground potential of these zones.
Following a review of previous work, it was concluded that no additional drilling is required at this historic high-grade pit in order to recommence production. Further, past mining was conducted based on a US$1100/oz pit shell while there is sufficient justification for a pushback to a US$1450/oz pit shell. Engineering is underway, and resumption of mining activity could commence as early as the 4Q20.
Great Panther holds approximately 2350 km2 in various stages of licensing, covering a largely unexplored greenstone belt in the Guyana Shield. The company's exploration team is strategically prioritising concessions according to their proximity with respect to Tucano's mill and geological potential. Most of these targets are early stage based on airborne magnetics, soil sampling, Auger and Rotary Air Blast (RAB) drilling. Approximately 27000 drilling m are planned for regional exploration in 2020, including 18 000 m of RAB and 9000 m of Auger drilling.
Read the article online at: https://www.globalminingreview.com/exploration-development/10022020/great-panther-provides-2020-exploration-plans-for-tucano-gold-mine/