Connect with us

Mining

The Future of Gold Exploration is Under Cover

Published

on

The Future of Gold Exploration is Under Cover

The Future of Gold Exploration is Under Cover

Over billions of years, extraordinary amounts of gold and other metals were deposited and spread throughout the Earth’s crust. Humans have been searching for these rich deposits for centuries, and advances in geoscience and technology have helped us become more adept at finding them over time.

However, even with today’s advancements – almost all early-stage prospecting methods are still based on the same key principle: trying to find areas of exposed bedrock, called outcrops, that indicate an orebody is near.

But such outcrops only form in certain circumstances – and what happens when a geological system doesn’t come in contact directly with the surface?

The Problem of Cover

Today’s infographic comes to us from Nevada Exploration, and it identifies the problem behind finding these “hidden” deposits that do not leave a helpful trail of clues on the surface.

Instead of having outcrops where rocks can be readily sampled, these deposits are trapped underneath large amounts of soil and gravel. Geologists call this a covered setting, where they must first find a way to “see through” the cover in order to identify what geological systems really exist below.

Seeing through cover can be expensive and difficult to do, but it also has big potential upside.

There is no reason not to assume as much gold still exists as has been mined in the past, but prospectors, explorationists, and geologists have found the easy gold.

– Dr. Richard Goldfarb, Ph.D., United States Geologic Survey

In fact, many geologists think that the next game-changing gold deposit could be found under cover.

Exploration 2.0

For explorers, it is no secret that the cost per discovery is going up dramatically over time. The reality is that traditional exploration methods are achieving diminishing returns, and as a result companies are settling for lower grade deposits, more complex geological settings, and politically questionable jurisdictions.

Minex Consulting says that between 2007-2016, there has been $65 billion spent globally on gold exploration with only $30 billion worth of discoveries to show for it. Those aren’t exactly inspiring economics for future gold explorers.

But for every industry problem, there is often a precedent to be found elsewhere – and an interesting situation that is analogous was faced by the oil exploration industry years ago. They had reached diminishing returns with shallow water deposits, and developed technology to go deeper. Suddenly, monster deposits were being found again.

Experts involved in mineral exploration see the same thing happening with cover.

With the transition to under cover exploration, the minerals industry is undergoing a transformation much like the petroleum industry transformed to deep sea exploration some decades ago.

– Cam McCuaig, Principal Geoscientist, BHP Billiton

In other words: whoever can figure out how to explore under cover could be reaping big benefits.

The Prize

In the world’s most prolific gold jurisdictions, there are massive amounts of land that have not yet been explored because of cover. In Canada and in Australia, over 70% of land is covered. In Nevada, which produces the most gold ounces per square kilometer, about 55% of land is covered.

Interestingly, Nevada has produced 225 million oz of gold to date, but the majority of these discoveries have come from outcrop clues on the surface. Imagine what gold could be hidden under soil and gravel within the valleys of the state.

Global data so far suggests that deposits discovered under cover tend to be 2-4x bigger.

Exploring Under Cover

While the idea of unlocking this potential is extremely exciting, it also poses a significant technical challenge.

Conventional tools are poorly suited to covered settings, and existing techniques for systematic exploration don’t work. The end result is high-risk, high-cost exploration.

To successfully explore through cover, companies need:

  • New technology to see through cover
  • A way to lower the costs of testing targets
  • A way to directly test covered bedrock

So far, a few ideas have been pioneered for seeing through cover – and it will be interesting to see what results they bring in.

Biogeochemistry: In Australia, explorers are using biogeochemistry as a hint to see what lays beneath the soil. Plants accumulate pathfinder elements in them, or even tiny amounts of gold, which allows explorers to get a hint at what lies deep below.

Hydrogeochemistry: In a place like Nevada, there are massive valleys in the middle of prolific gold districts that have remained unexplored because they are covered with hundreds of meters of gravel. Testing groundwater might be the key, because groundwater flows by gravity from mountains to deep in the valley centers. On the way, this water interacts with bedrock – and any gold deposits that are hidden beneath the surface.

Explorers are looking at other ideas as well, ranging from regional-scale mapping to adapting other oil and gas industry techniques. If any of them are able to unlock the secret of exploring through cover, it could be the catalyst for industrywide change, as well as the discovery of the monster deposits that will meet our mineral needs of the future.

Click for Comments

Uranium

Charted: Global Uranium Reserves, by Country

We visualize the distribution of the world’s uranium reserves by country, with 3 countries accounting for more than half of total reserves.

Published

on

A cropped chart visualizing the distribution of the global uranium reserves, by country.

Charted: Global Uranium Reserves, by Country

This was originally posted on our Voronoi app. Download the app for free on iOS or Android and discover incredible data-driven charts from a variety of trusted sources.

There can be a tendency to believe that uranium deposits are scarce from the critical role it plays in generating nuclear energy, along with all the costs and consequences related to the field.

But uranium is actually fairly plentiful: it’s more abundant than gold and silver, for example, and about as present as tin in the Earth’s crust.

We visualize the distribution of the world’s uranium resources by country, as of 2021. Figures come from the World Nuclear Association, last updated on August 2023.

Ranked: Uranium Reserves By Country (2021)

Australia, Kazakhstan, and Canada have the largest shares of available uranium resources—accounting for more than 50% of total global reserves.

But within these three, Australia is the clear standout, with more than 1.7 million tonnes of uranium discovered (28% of the world’s reserves) currently. Its Olympic Dam mine, located about 600 kilometers north of Adelaide, is the the largest single deposit of uranium in the world—and also, interestingly, the fourth largest copper deposit.

Despite this, Australia is only the fourth biggest uranium producer currently, and ranks fifth for all-time uranium production.

CountryShare of Global
Reserves
Uranium Reserves (Tonnes)
🇦🇺 Australia28%1.7M
🇰🇿 Kazakhstan13%815K
🇨🇦 Canada10%589K
🇷🇺 Russia8%481K
🇳🇦 Namibia8%470K
🇿🇦 South Africa5%321K
🇧🇷 Brazil5%311K
🇳🇪 Niger5%277K
🇨🇳 China4%224K
🇲🇳 Mongolia2%145K
🇺🇿 Uzbekistan2%131K
🇺🇦 Ukraine2%107K
🌍 Rest of World9%524K
Total100%6M

Figures are rounded.

Outside the top three, Russia and Namibia both have roughly the same amount of uranium reserves: about 8% each, which works out to roughly 470,000 tonnes.

South Africa, Brazil, and Niger all have 5% each of the world’s total deposits as well.

China completes the top 10, with a 3% share of uranium reserves, or about 224,000 tonnes.

A caveat to this is that current data is based on known uranium reserves that are capable of being mined economically. The total amount of the world’s uranium is not known exactly—and new deposits can be found all the time. In fact the world’s known uranium reserves increased by about 25% in the last decade alone, thanks to better technology that improves exploration efforts.

Meanwhile, not all uranium deposits are equal. For example, in the aforementioned Olympic Dam, uranium is recovered as a byproduct of copper mining occurring at the same site. In South Africa, it emerges as a byproduct during treatment of ores in the gold mining process. Orebodies with high concentrations of two substances can increase margins, as costs can be shared for two different products.

Continue Reading
NOVAGOLD. Pure gold. Precious opportunity.

Subscribe

Popular