Dust off your picks and axes, Fools … we're going prospecting for world-class gold mines.

This multi-year bull market for gold has generated plenty of interest in locating major new deposits to sustain global production amid this robust demand environment. The problem, as AngloGold Ashanti (NYSE:AU) CEO Mark Cutifani points out, is that major discoveries are getting "a lot harder to find." Indeed, his company has made no new gold discoveries in heavily mined South Africa during the past 20 years.

In a market that needs to replace more than 100 million ounces per year to maintain a balanced supply (according to Barrick Gold (NYSE:ABX) CEO Aaron Regent), production is increasingly accomplished through scores of smaller operations around the world … which of course requires more effort. The declining role of larger-scale operations raises development and operating costs for the industry at large, and further supports expectations for continued consolidation throughout the gold mining sector.

A changing of the guards
This shift in production scale is epitomized by the rise of China as the world's leading gold producer since 2007, just as South Africa entered a more mature stage of its productive cycle. Reaching extreme depths of two miles or more beneath the surface, mine safety incidents and related stoppages have plagued South African miners, with Gold Fields (NYSE:GFI) reporting another fatality just this week. After leading world production from 1905 to 2006, South Africa's monster mines are significantly tapped out. China launched to the top spot not through a handful of massive mother lodes, but through the sheer scope of smaller-scale operations underway.

Although singularly massive gold deposits are increasingly hard to find, they do still exist, and Fools seeking economies of scale in their gold exposure are encouraged to consider the world-class mines within their selection process. Now, let's take a look at a few of the most impressive deposits on the planet.

Even though they placed the word gold right in the company's name, Freeport McMoRan Copper & Gold (NYSE:FCX) is frequently mischaracterized as a pure play on copper. That same Grasberg mine in Indonesia that supplies the world with 1.3 billion pounds of copper annually also contains the richest gold reserves of any single mine. With 38.5 million ounces of proven and probable gold reserves remaining, alongside 35.6 billion pounds of copper, this company enjoys a veritable cash flow machine as the keystone of its global operations. Despite substantial debt of more than $7 billion, I consider Freeport an enticing play on copper and gold on the strength of that in-ground, bi-metallic ATM at Grasberg.

Peru is home to the next world-class gold mine of note, at Yanacocha. Operated by Newmont Mining (NYSE:NEM) through a joint venture with Compania de Minas Buenaventura, the deposit contains some 27.5 million ounces of gold reserves. After a second mill at the mine was commissioned in 2008 to improve gold and silver recovery rates, Yanacocha is positioned as a stronghold for Newmont and partner Buenaventura to last for years to come.

After recently consolidating ownership of the impressive Boddington mine in Australia, containing 11.1 million ounces of gold reserves, Newmont boasts a couple of monster mines in its gilded global portfolio. Although the world's leading producer, Barrick Gold, brings a pair of 17 million-ounce behemoths to the table -- with Pascua Lama in Argentina and its half of the Donlin Creek joint venture in Alaska -- both projects remain in pre-construction phases of development. With Yanacocha already cranking and Boddington set for commissioning this summer, this Fool considers Newmont far more attractive than Barrick.

We now arrive at the mine that I find most enticing from an investor's perspective. Goldcorp's (NYSE:GG) Penasquito mine in Mexico reached an important milestone this week, announcing mechanical completion on the first of two sulphide processing lines. At this late stage of construction, with operations commencing later this year and commercial production early in 2010, this report of construction remaining on time and on budget is excellent news. Penasquito's mineral wealth of 17.4 million ounces of gold is bolstered by an enormous silver supply of more than 1 billion ounces. My Foolish readers know that while I expect strong price performance for gold over the coming years, I expect even bigger strides for silver thanks to what I call the slingshot effect.

Penasquito comprises a core foundation for Goldcorp's anticipated 50% increase in production by 2013, and it is large enough in scale to meaningfully enhance cash flow for royalty holder Royal Gold and silver stream specialist Silver Wheaton (NYSE:SLW). With prospective growth in low-cost gold production well in hand, Goldcorp now earns this Fool's nod as the best-positioned miner among the elite major producers.

We have quickly sped around the world for a glimpse of noteworthy mines, but we've barely scratched the surface. Successful mining investors know that plenty of research is recommended, so it's important to enjoy the adventure.

Further Foolishness:

Gold is a hot topic on the blogs at Motley Fool CAPS. Join the free service today and see just how many Fools are taking the long view when it comes to investing in gold. The "Gold" tag at CAPS lists 41 potential investments, and you'll find Christopher's comments on most of them.

Fool contributor Christopher Barker thinks you can guess which of the James Bond movies he prefers. He can be found blogging actively and acting Foolishly in the CAPS community under the name TMFSinchiruna. He tweets. He owns shares of Freeport-McMoRan, Silver Wheaton, and Royal Gold. The Motley Fool has a gilded disclosure policy.