Gold rushes have changed history, geography, and personal fortunes throughout the ages. They have also created dramatic shortages of key items and led to innovative ideas to overcome those shortages.
The current global gold rush is no different. Recent record gold prices have created a dramatic leap in demand for a whole range of items. With many of the world’s richest gold zones often located in remote areas of the earth, these shortages can be ever further exaggerated.
Two of the most significant items affected by the current demand are drilling equipment and assay capacity. The cost of drilling rigs and crews has climbed over the past year – that is if you can even contract one.
Meanwhile, the demand on assay labs has seen turnaround times for key drilling results continue to expand. In parts of Australia, junior miners are now waiting for up to 10 weeks before being able to announce key results to the market.
The situation has seen a number of miners across the globe decide they will undertake some of their exploration in core libraries or data banks.
An historic discovery in Australia
In Australia, Indiana Resources (ASX: IDA) recently made a data mining breakthrough when it uncovered an historic gold assay that had laid hidden in the annals of the South Australian mineral core library for nearly six years.
The company believes its decision to re-examine the historic core held by the South Australian Government could lead to a golden pay off after wide mineralized intersections were observed in a historic drill hole drilled by a previous operator at the Minos Prospect within Indiana’s 100% owned Central Gawler Craton Gold Project.
The company elected to assay the historic diamond drill hole drilled in 2015, uncovering impressive intersections such as 20m @ 1.55 grams per tonne gold from 32m, including 2m @ 2.84 g/t from 34m and 5m @ 3.48 g/t from 43m.
Indiana’s subsequent maiden drilling campaign at Minos has hit promising gold intersections which have exceeded the company’s initial expectations and it is now moving quickly to finalize follow-up RC and Diamond drilling programmes for the next two months.
North American gold explorers looking to the past
In the U.S., Stevens Gold Nevada Inc.’s (CSE: SG) data mining of historic geophysical and soil geochemical surveys on the optioned Millennium Gold Property has identified a number of new targets at the Arizona project.
The company recently reported it had extracted useful information to aid exploration by mining historic geoscientific databases. One useful “titbit” was a 2007 programme of virtual grid-based soil geochemical surveys based on Mobile Metal Ion Technology (MMI) undertaken on the Millennium Gold Property, which successfully delineated multiple strongly elevated gold responses.
Historic ground magnetic surveys were also carried out on the property in 2008 by Zonge Engineering and I.P. geophysical surveys in 2011 by Durango Geophysical Operations. The company said these historic results are “value-added information” and will assist more focused exploration on the property using modern exploration techniques and drilling.
In Canada, a historical review conducted by Cross River Ventures Corp.’s technical team has identified several promising gold targets at its 100% owned Manitou Gold Project in north-west Ontario.
Exploration at the Manitou property began in the early 1900s with trenching, and minor gold production. Modern exploration began in 1965 and continued until 2015, with several companies and small-scale vendors conducting a variety of exploration programmes.
Reviewing timelines of the limited historical work suggests periods of lower gold prices interrupted steady exploration on the property. The technical team’s review of work at Manitou has now identified the potential for shear-zone hosted gold.
The Ontario Mineral Database records 16 gold occurrences within the land position, most of which contain shear-hosted gold and sulphide mineralization. Several of the occurrences were mined and variable amounts of ore were historically extracted from small-scale workings.
Meanwhile, Fortune Bay Corp. (TSXV: FOR) used its historical studies and its successful application for a drilling permit for its Goldfields Project in northern Saskatchewan, Canada.
The company’s technical team undertook an extensive review of historical data, which helped develop targets and a drilling plan with the potential to expand the historical mineral resources at both the Box and Athona deposits within the Goldfields Project.
The last drilling campaign at Goldfields was completed in 2011 and the company said it looked forward to reviving exploration on the project equipped with an improved geological understanding of the deposits.
The primary objective of the drilling programme is to expand the historical mineral resources beyond the extents of the historical mineral resource estimates and current drilling coverage.
At Athona South, planned drilling includes confirmatory drilling to verify 1930s historical results, infill drilling to establish continuity with mineralization to the north, and step-out drilling to the south.
Renewed focus driven by the EV push
But databank explorers aren’t only chasing historic gold.
Avidian Gold Corp.’s (TSXV: AVG) subsidiary High Tide Resources Corp., recently increased its land position significantly at its Lac Pegma Copper-Nickel-Cobalt sulphide deposit in Quebec.
Buoyed by the demand for EV battery minerals, High Tide elected to conduct a desk-top study and preliminary modelling based on a review of the historical exploration data from the Lac Pegma area. The review focused on a historic copper-nickel-cobalt sulphide deposit discovery made by Diadem Resources in 1996, long before LIBs and EVs were part of explorers’ thoughts.
Back in Australia, a review of historical IP data collected on the Wyacca Prospect in South Australia in the 1960s has helped Taruga Minerals Limited (ASX: TAR) identify a well-defined IP anomaly with an associated low resistivity anomaly has been defined over a distance of at least 1.7km.
The IP anomaly is coincident with tree historic copper workings which reported rock chip results of up to 21.6% Cu and 11.4 g/t Ag.
CEO, Thomas Line, said the mapping further identified a number of parallel mineralized brecciaswhich reported up to 11.6% Cu and 23.2g/t Ag.
“The reprocessing and modelling of the historical IP survey has confirmed a strong association exists between the IP chargeability anomaly, high-grade rock chip samples, and significant historical drill intercepts,” Mr Line said.
“This further highlights the copper and silver potential at Wyacca. The survey shows that only two of the historical holes, which also contained the best historical intercepts at Wyacca (CAMS W2 and CAMS W3), were drilled in close proximity to the IP anomaly and were stopped short of intersecting the main body of the anomaly at depth.
“Taruga will plan a number of angled holes across the IP anomaly, which will show the grade potential and true width which is expected to exceed 50m from historical drilling. Field mapping and sampling has further highlighted the potential at Wyacca where a number of east-west striking parallel, mineralized breccias were identified for follow-up with drilling.”
And the move to data libraries hasn’t only been about finding forgotten discoveries.
Candente Copper Corp. (TSX: DNT) recently engaged Ausenco Engineering Canada Inc. to conduct Desk Top Studies to identify and define a smaller, higher grade, start-up option for its Cañariaco copper-gold-silver project in Peru with a smaller initial capital expenditure and accelerated payback period
Assuming favourable results from the desk-top studies, the company said it would look to move into a Preliminary Economic Assessment (PEA) on a Revised Project Concept which would be expected to take approximately four months to complete.
While drilling is described by old school explorers as the ultimate “truther”, there is no doubt that exploring for mineral riches in historic records can really pay off.