This article is a sponsored feature from Mining.com.au partner New Age Exploration Limited. It is not financial advice. Talk to a registered financial expert before making investment decisions.
There’s talk of a new gold rush in Central Otago as a series of companies flock to stake their claims around newly discovered gold deposits.
Recent exploration work at Santana Mineral’s (ASX: SMI) Bendigo-Ophir project has yielded some of the richest gold finds in New Zealand history, with astute explorers eager to get in on the action.
Importantly, many of the gold-bearing rocks in the area are exposed at the surface, making them easy to locate and mine. With modern technology, gold can be extracted from even low-grade ore, making it economically viable to mine even small deposits.
Central Otago – a proud gold mining history
The region has a strong gold mining history, with several rushes in the 1850s leading up to the famous Otago rush of 1861 which saw thousands or prospectors flock to the region in search of riches.
Despite exploration and commercial mining peaking in the late 19th and early 20th centuries, New Zealand has remained somewhat of a force in the precious metal market, responsible for production of roughly 370,000 gold ounces per year and, according to local geologists, plenty of untapped potential remains.
OceanaGold’s Macraes Gold Mine has been carrying the flag for the region. The large open-pit mine is New Zealand’s highest-volume producer at around 150,000 ounces per year, extracting gold from a deposit of gold-bearing quartz veins. The mine employs over 500 people and is a major contributor to the local economy, estimated to have generated NZ$1.5 billion in GDP for the Otago region since operations began.
Bendigo-Ophir discovery triggers new gold rush
The gold discovery at the Bendigo-Ophir project, located within the highly-endowed Central Otago Schist Gold Belt, sent shockwaves through the gold mining industry with the project yielding some of the most outstanding gold results in the region’s long history.
The release of a 643,000oz Inferred Mineral Resource in 2021 delivered proof that the region has plenty to offer, with a number of companies staking claims in search of further discoveries.
Australian miner New Age Exploration has taken centre stage with a series of strategic tenement purchases that it predicts will deliver significant results
And of these, Australian miner New Age Exploration (ASX:NAE) has taken centre stage with a series of strategic tenement purchases that it predicts will deliver significant results.
Lammerlaw – prime real estate
In what would become its primary New Zealand project, NAE was granted a 265 km² Prospecting Permit covering the Lammerlaw area in Otago following a competitive application process during December 2019.
The permit encompasses the Bella Lode, which was historically mined through the late 1800’s, averaging 15 g/t over 0.6m to 1.8m thickness, before closure in 1901.
Lammerlaw also covers a historically-mined antimony lode and scheelite (tungsten) workings, as well as minor occurrences of copper, silver, and mercury.
New Zealand’s largest alluvial gold deposit, Gabriels Gully, is located approximately 3km to the south of the permit. The deposit, whose source remains unidentified, has produced over 500,000 gold ounces and was the site of Gabriel Read’s gold find that led to the major rush of 1861.
The first phase of ground exploration targeting Macraes-style, shear-hosted gold targets on the Lammerlaw Permit was completed in June 2020 by NAE’s NZ-based technical team. This initial phase included a mapping program and sampling of bedrock, saprolite and alluvial soils to a depth of 1m.
The mapping program identified a number of areas with similar geological characteristics to known gold-bearing areas in the Macraes region, and these areas will be targeted in the next phase of exploration.
The soil sampling program returned a number of anomalous results, including one sample with gold values of up to 1.7g/t. These results will be used to narrow down the focus of future exploration work on the permit.
In total, 217 soil samples and 52 rock chip samples were collected for analysis by pXRF and fire assay, and structural measurements & lithological descriptions were collected at 61 outcrop locations.
Results from the program included 7 anomalous readings of between 12 to 33ppb gold, and 10 to 100ppm arsenic, pointing to potential for shear-hosted gold mineralisation along metamorphic boundaries.
Of particular importance are the four anomalous gold and arsenic results located near the historic Bella Lode mine, which extend a soil anomaly to over 1.5km in strike, and up to 600m from the metamorphic boundary.
Overall, this first phase of exploration has been successful in identifying potential gold targets on the Lammerlaw Permit, and further work is warranted in order to fully assess potential.
OPQ presents high-priority targets
The OPQ Gold Target, comprising a 71.6 km² exploration permit, is a high-priority gold exploration target located in the Mahinerangi area of Otago.
The permit adjoins Lammerlaw to the northwest and contains two primary gold exploration targets: the OPQ Reef gold target, and Macraes-style shear-hosted gold exploration targets.
The OPQ Reef target is a high-grade, vein-hosted gold deposit that has been identified through geochemical and geophysical surveys. The vein, located 65m below surface, stretches for over 1.2km and averages 2m in width. It was first mined in the early 1900s and has since yielded gold grades averaging 13 g/t.
The target is situated within an area of strong structural control and is believed to be associated with a regional shear zone. With further exploration, NAE believes that the OPQ reef could provide a significant source of future gold output.
During 2018 and 2019, NAE undertook a series of soil sampling programs at OPQ Reef using hand auger and man-portable drills. A total of 10 high-grade anomalous results were collected, ranging between 0.1 g/t and 2.5 g/t gold, with results suggesting the potential for around 6 km in strike.
The Macraes-style targets are lower-grade, shear-hosted gold deposits that have been identified through geological mapping and geochemical surveys. The targets are situated within a region of known gold mineralisation and are believed to be associated with a large regional shear zone.
The Macraes Mining Company undertook exploration around the OPQ historic mine area between 1991 and 1997. This exploration further demonstrated arsenic and gold soil anomalies over 1km of strike.
In 2020, further exploration work was carried out by NAE, with a focus on identifying potential shear-hosted gold mineralisation along metamorphic boundaries. This work led to the identification of several areas of interest, which will be the focus of future work programmes.
Emerging opportunity at Manorburn and Marlborough
Other important applications held by NAE include the 221.8km² Manorburn opportunity, which is located next to the Bendigo-Ophir Gold Project, along with the 500km² Marlborough prospect. This project sits within the Marlborough Schist Belt, which is described by NAE as a northern analogue of the Otago Schist Belt offset.
Following the granting of a prospecting permit, exploration at Manorburn has recently begun, with field mapping and surface geochemical investigations due to begin, followed by drill testing of major target regions.
NAE Executive Director, Joshua Wellisch explains: “The granting of the Manorburn permit strengthens our position in New Zealand and Otago where we already have a well-advanced gold exploration program with the Lammerlaw and OPQ Exploration Permits. Manorburn adjoins Santana Minerals (ASX:SMI) recent Gold discovery in Bendigo-Ophir providing an exceptional opportunity to advance our exploration efforts within this highly prospective Gold district in New Zealand. We look forward to providing further updates as we accelerate our programs.”
2022 began with the successful grant of a prospecting permit for Manorburn, followed by boots on the ground at the project.
Following a review of past exploration data, a number of major target regions have been identified, and field efforts will involve mapping and surface geochemical studies.
NAE continued its ridge and spur soil sampling programme along electromagnetic lineation at Lammerlaw during the recent summer field season in search of mineralised shearing and veining.
Gold assay results from infill soil sampling undertaken earlier in 2021 have yielded a number of prospects, with strong north-west trending gold-arsenic anomalies ranging in strike extent from 200m to 1,000m.
After securing an access arrangement to farms on its exploration permit, the business plans to begin Phase 2 trenching activity at OPQ, which will target basement schist in areas shallower than 2m from surface.
Following that, a Phase 3 program will be designed that will include RC and diamond drilling to evaluate the depth of southern strike extensions.