Her students drill core samples and swab the walls with Q-Tips, daubing them onto petri dishes.

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In its Fruta del Norte site a drill core showed a rich 32 troy ounces of gold per ton of rock.

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To determine whether a deposit has enough of a mineral to merit mining, companies use air-based geological mapping and drill for core samples.

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During the third quarter, the company continued what it described as an aggressive drill campaign with 13 core and 10 reverse circulation rigs in operation.

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