From Ferdinand Magellan to Neil Armstrong, the sagas of legendary explorers are routinely condensed into a timeline of fateful achievements. For small-cap gold explorer Paramount Gold (AMEX: PZG), this is one of those defining moments.

Within the same Sierra Madre Occidental silver and gold belt in Mexico that hosts some of the industry's most exciting discoveries, Paramount Gold has delivered on its niche strategy of developing prospective properties in the vicinity of proven lodes that support existing mines. With a fresh new discovery at its San Miguel property, Paramount has not only created the promise of substantial resource expansion right in Coeur d'Alene Mines' (NYSE: CDE) backyard, but it claims to have struck a direct extension of the Palmarejo geological structure that hosts Coeur's world-class mine of the same name.

Before we delve into the particulars, we need to establish some context. San Miguel is located within a concentration of gold and silver mines that include Goldcorp's (NYSE: GG) El Sauzal mine to the south, and Minefinders (AMEX: MFN) Dolores mine well to the north. Gammon Gold (NYSE: GRS), which I recently highlighted as a turnaround story in the making, continues to make exciting new discoveries at its nearby Ocampo mine. But all the while, it's the adjacent location of Coeur's Palmarejo mine -- with reserves of 90.5 million ounces of silver and 1.1 million ounces of gold -- that rendered San Miguel such a striking opportunity for Paramount.

You see, Paramount seeks to inhabit a "sweet spot" of shareholder value creation by expanding known deposits, proposing mine plans, and seeking joint ventures with established producers to advance into production. It's likely that Coeur was already paying close attention to Paramount's prior exploration success at San Miguel, but this discovery of an extension of the Palmarejo deposit itself moves the project squarely into Coeur's sphere of strategic growth opportunities. Coeur itself has touted recent exploration success on what appears to be the same vein structure, and has thus far identified a 2.4 kilometer strike length. If Paramount is correct, then Coeur's Guadalupe target is geologically contiguous with Paramount's Don Ese vein.

Delineation drilling will be required to better understand the scale of this discovery, but these first indications appear promising indeed. Paramount has identified an impressive strike length of 550 meters already, while the feature is considered likely to extend deeper and continue longitudinally for another 200 meters or more. Several early intercepts have yielded gold and silver grades well in excess of Palmarejo's average gold grade of 1.86 grams per ton. One drill hole in particular returned a 13.4-meter interval grading 6.53 grams of gold per ton, and 590.4 grams of silver per ton.

Fools seeking the clearest prospects for organic resource growth may wish to give ample consideration to Paramount Gold. The Don Ese vein is but one of several high-quality discoveries made within the San Miguel project to date, and ongoing exploration at the company's Sleeper project in Nevada offers another locus of compelling opportunities.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.