Gold mineralization in the Nicolson’s Find area is structurally controlled within the 400 m wide NNE trending dextral strike slip Nicolson’s Find Shear Zone (NFSZ) and is hosted within folded and metamorphosed turbiditic greywackes, felsic volcaniclastics, mafic volcanics and laminated siltstones and mudstones. This zone forms part of a regional NE-trending strike slip fault system developed across the Halls Creek Orogen (HCO).

The NFSZ comprises a NNE-trending anastomosing system of brittle-ductile shears, characterised by a predominantly dextral sense of movement. The principal shear structures trend NNE to N-S and are linked by NW, and to a lesser extent, by NE shears. Individual shears extend up to 500m along strike and overprint the earlier folding and penetrative cleavage of the HCO.

The overall geometry of the system is characterized by right step-overs and bends/jogs in the shear traces, reflecting refraction of the shears about the granite contact. Within this system, the NW- striking shears are interpreted as compressional structures and the NE striking shears formed within extensional windows. Mineralization is primarily focussed along NNE trending anastomosing systems of NNE-SSW, NW-SE and NE-SW oriented shears and splays. The NNE shears dip moderately to the east, while the NW set dips moderately to steeply to the NE. Both sets display variations in dip, with flattening and steepening which result in a complex pattern of shear intersections.

Mineralisation is strongly correlated with discontinuous quartz veining and with Fe-Si-K alteration halos developed in the wall rocks to the veins. The NE shears are associated with broad zones of silicification and thicker quartz veining (typically white, massive quartz with less fracturing and brecciation); however, these are typically poorly mineralized. The NW-trending shears are mineralized, with the lodes most likely related to high fluid pressures with over-pressuring and failure leading to vein formation. Although the NE structures formed within the same shear system, the quartz veining is of a different generation to the mineralized veins.

Individual shears within the system display an increase in strain towards their centres and comprise an anastomosing shear fabric reminiscent of the pattern on a larger scale.

The Nicolsons Project is Pantoro’s currently producing operation. The Project is underpinned by the high grade Nicolsons Underground Mine with the second underground mine, Wagtail, under active development. Nicolsons has been producing gold since September 2015.

Nicolsons Underground Mine
The Nicolsons underground mine is located adjacent to the Nicolsons processing plant and has continued to be the cornerstone of production at the operation. The mine operates three main ore lodes being the Hall, Anderson, and Johnston Lodes. Development within the ore-body has revealed continuing mineralisation at depth, and has often out-performed drilling indications. This has been a common outcome within the mine since commencement of operations. Pantoro continues to apply significant in-mine exploration expenditure at Nicolsons with a view to replacing mine depletion and continuing to grow Ore Reserves at the mine.

Nicolsons underground mine is located adjacent to the Nicolsons processing plant and has continued to be the cornerstone of production at the operation. Development has progressed to approximately 380 metres below surface at the time of reporting.

Ore was primarily mined from the Johnston and Anderson Lodes during the period. In the Anderson Lode, Pantoro modified mining methods during the period in response to ground related issues reported in the first quarter of the financial year. The modified method utilises a combination of mechanized cut and fill, and uphole benching. Drilling at depth has confirmed ongoing high grade results at depth in the Anderson Lode with the Ore Reserve currently extending to approximately 420m below surface. The Inferred Resource currently extends to approximately 500m below surface. As the mine has progressed, ore zones have plunged towards the North, and capital mine infrastructure is being transitioned towards the core of the high grade zone.

Wagtail Underground Mine
Wagtail is located adjacent to the Nicolsons Underground Mine. Pantoro commenced mining Wagtail (and the nearby Rowdies mine) as open pit operations in October 2016.

Open pit mining at Wagtail was successful with production exceeding modelled Ore Reserves, and mining revealing a structural architecture similar to what has been observed at the Nicolsons Underground Mine.

Open pit mining operations at Wagtail ceased in December 2017 as planned and work to begin underground mining commenced soon afterwards. Final regulatory approvals to commence underground mining were received in May 2018, and surface works to commence mining began immediately. Underground development at Wagtail has proceeded well and Pantoro expects to begin ore production in the December 2018 quarter.

Wagtail North Underground Mine
Underground mining at Wagtail commenced in June 2018, and has progressed substantially during the year. The underground decline portal was established in the southern end of Wagtail North pit, and development currently accesses the Wagtail north and Rowdies ore bodies.

The first ore level was established on the 2200 level, and the decline has now progress to the 2155 Level, providing four level access points. While ore development has advanced slightly behind schedule, ore has now been developed along the entire strike length of the Wagtail North and Rowdies Ore Reserves, and gold mined to date has marginally exceeded Ore Reserve expectations.

Wagtail South
Pantoro commenced an open pit expansion at Wagtail South in March 2019. The decision to undertake additional open pit mining at Wagtail South was primarily driven by the definition of additional ore through development of small adits in the open pit wall. The adits demonstrated continuity of ore to the north of the previous final pit. Coupled with the increased gold price, the additional ore allowed the open pit to be mined approximately 25m deeper on the Eastern side of the pit.

Development of the open pit has progressed in line with plan during the period, and completion is expected to be achieved in early in December 2019. The majority of the ore is planned to be mined during the September – December 2019 period in accordance with the mine plan.

An underground mine is already approved at Wagtail South. The operations team is currently assessing the access approach to Wagtail South following the open pit expansion, with a new portal and underground access from Wagtail North both possible.

Underground Mine Progress
Mining continued from both Wagtail and Nicolsons throughout the quarter.

The majority of development work continues to be focused on Wagtail north areas, and in particular the Rowdies, REV, and Wagon Lodes. The active mining areas continue to perform well in comparison to the Mineral Resource, and ongoing underground extensional drilling and development has continued to extend beyond the Ore Reserve at depth.

Development of the south decline progressed during the quarter with drilling undertaken to test depth extensions in the Wagtail North orebody, while development is advancing towards Wagtail South. As expected, additional zones of mineralisation have been encountered with development and drilling. Assay results for extensional drilling undertaken in Wagtail North are pending.

At Nicolsons, the majority of ore mined was from the Johnston orebody in the south of the mine with airleg mining as the primary method. Pantoro now has a second single boom jumbo on site, to be utilized in development and extraction of multiple remnant areas within Nicolsons mine. Extraction of remnant zones will commence during the current quarter.

The Halls Creek Project was developed by Pantoro during 2015, with the first gold pour completed during the same year. The project includes underground and open pit mining, and a modern CIP processing facility.

In June 2018 Pantoro commissioned a Steinert ore sorter and new processing circuit at Nicolsons. The ore sorter has been operating effectively enabling the upgrade of low grade stockpiles and medium grade ore from mining operations. Full time operation is expected as ore feed from Wagtail and Nicolsons ramps up.