Mineral prospecting around New Zealand is still being encouraged by Government permitting agency New Zealand Petroleum & Minerals, but costs and the advent of new technology are beginning to detract from the historical role.
The two blocks, covering parts of Otago and Southland, essentially surround an existing 13,000sq km area within Otago which has already been surveyed by former Glass Earth Gold (now Antipodes Gold), then the country's largest exploration company.
The company has since departed Otago.
NZPM has three tiers for mineral exploration:
• a relatively low-impact hand-sampling prospecting permit;
• a higher level exploration permit of more detailed sampling, including test drilling;
• production mining.
NZPM national manager minerals Ilana Miller said there was still a place for small, start-up prospectors ''on a variety of scales''.
''The New Zealand minerals sector covers the full spectrum, from small hobby permit miners to junior explorers and global miners.
''Some of the best discoveries globally are made by small operators that are savvy with publicly available data.
''There are still plenty of opportunities to explore and make discoveries in New Zealand,'' Ms Miller said, in response to questions on prospecting permits.
NZPM assists explorers by providing online access to maps and historical geological data, she said.
Concerns have been raised by small prospectors with the ODT during the past two years that NZPM's costs for a permit are escalating and the paperwork required is too stringent for small operators to carry the cost of compliance on issues such as health and safety and environmental impacts.
Prospecting around New Zealand has had a huge surge in popularity: permits more than tripled from 10 issued in 2010 to 34 in 2012.
Between mid-2005 and late 2011, global spot gold prices soared more than 370% - from $US400 to a peak in September 2011 of about $US1900, for a time underpinning the viability of small gold operations.
Ms Miller said permit holders paid an administration fee and annual permit fees to NZPM.
''These are charged on a cost-recovery basis ... designed to reflect the actual staff cost of processing,'' she said.
Since 2010 the application fee for a prospecting permit has been $1635.55 (incl GST), while the annual fee payable under a prospecting permit is $3.58 per square kilometre or $511.11, whichever is greater.
A prospecting permit covering the maximum 500sq km allowed would cost $1790 in fees each year, she said.
Fees review
NZPM undertook a partial review of fees last year, and was now reviewing its full fees, she said.
However, for many prospectors spoken to recently, there are in some cases the additional requirements of lengthy consultation with local councils, iwi, the Department of Conservation, environmental groups or Fish & Game, plus resource consenting and land access agreements to secure.
On the question of health and safety and environmental requirements, Ms Miller said those had been strengthened in recent years to bring New Zealand's regulatory regime in line with international best practice.
''The changes were in response to events such as the Gulf of Mexico oil spill, the Pike River mine tragedy, and the Rena [grounding and oil] spill,'' she said.
NZPM had a role to play by offering proactive leadership, to be the first point of contact for most operators and assist them to understand the regime.
''I do not see the regulatory regime as being a massive barrier to investment,'' Ms Miller said.
NZPM held annual review meetings with selected permit holders and invited other relevant regulators, such as WorkSafe and local councils.
When asked, Ms Miller said she did not believe mineral prospecting had become outdated, by the nature of its small-scale efforts requiring long, relatively low-technology exploration.
''Not at all. Essentially they are about gathering basic data to see if minerals exist in an area,'' she said.
While New Zealand had a long history of minerals prospecting and exploration, some areas required additional investigation.
''While alluvial gold deposits in the South Island are largely understood, garnet [an industrial mineral] deposits in the West Coast mineral sands are not,'' she said.
''NZPM are currently considering a number of prospecting permits for minerals such as garnets, to evaluate whether these occur in quantities worth pursuing.''
Prospecting permits allowed smaller to mid-sized companies to get involved - with the work programme requirements less onerous and costly - and to make new discoveries.
''This means smaller companies can begin with prospecting, potentially make a discovery and bring in more investment/larger operators at a later date if they want to apply for an exploration permit and undertake more detailed work,'' she said.
Sometimes larger companies could apply directly for an exploration permit.
It was important to note prospecting activities would never give the same amount of data that test drilling could, under an exploration permit.
''NZPM wants the best return for New Zealanders, which means we want the best evaluation techniques and methods for the mineral type to be used,'' she said.
Aeromagnetic surveying
Ms Miller did not believe aeromagnetic surveying was replacing the work of prospecting, but rather was complementing the other geological assessments.
''Geologists use a variety of tools to build up a picture of mineral occurrences,'' she said. Prospecting generally involved a desk-top study, using publicly available data, including aeromagnetic surveys, plus geological mapping and the hand sampling of rocks.
''Aeromagnetic surveys can be over areas where there is little mineral data and in areas which the minerals are better understood, to further improve that understanding,'' she said.
Once the upcoming Otago aeromag surveys were completed, the combined industry and government surveying would mean a third of New Zealand was covered by aeromag, she said.
When asked, she said Minister of Energy and Resources Simon Bridges was not reviewing the future of prospecting permits.
In 2013, as part of several changes to the Crown Minerals Act, the size of prospecting permits was restricted to a maximum of 500sq km. That ensured companies did not take up large swathes of land and allowed other individuals or companies to get permits, she said.
''That 500sq km is a fair and reasonable maximum size to methodically evaluate perceptivity within the two-year life of a prospecting permit.
''The maximum area also offers plenty of room to make a discovery.''
Ms Miller said the Ministry for Business, Innovation and Employment was planning an internal review of how NZPM allocates minerals permits.
Minerals permits are allocated several ways, including ''priority-in-time'' - where the applicant requests a permit from NZPM covering a certain area - and ''newly available acreage'', which is run like a mini competitive tender.
NZPM also ran competitive ''minerals tenders'' rounds, which included one in Northland, another for epithermal gold in the central North Island and for a platinum area in the South Island.
Around Otago, applications for prospecting permits are not being accepted until 2017.
Ms Miller said once the aeromag surveys were completed, and data processed, NZPM would analyse the data and consider the best means of allocation.
''This may include allowing priority-in-time permitting or [a competitive] minerals tenders; in which case reservations on exploration and mining permits would need to be put in place.''
