RE:Is Sirios really interesting for a big company?The most famous of the worlds shallow deposits is the Carlin Trend in Nevada. Here microscopic gold is found in almost every rock. The gold is low-grade (under one gram per tonne) but plentiful. Between 1835 and 2008 a whopping 152 million ounces was pulled from the Carlin Trend and other gold trends in Nevada, including Cortez and Walker Lane, mostly through open-pit mining. Some Nevada pits are now depleted and have moved underground. The technique of heap leaching wherein mining companies pile ore onto large piles and irrigate them with leachate originated in Nevada where near surface ore is oxidized. The leachate percolates through the ore, thereby dissolving the gold. While heap leaching for metals has been known about for hundreds of years, it wasnt until 1969 that the first gold and silver heap leap operation began at Cortez in Nevada. Barrick Nevadas Cortez property is still going, with ore drawn from the Pipeline complex open pit, and Cortez Hills, a combination underground/ open pit mine. Heap leaching technology was a major breakthrough because it significantly reduced gold recovery costs (versus traditional cyanide leaching see section below on gold recovery costs) for low-grade but high-tonnage Carlin deposits such as those found in Nevada. An example of a low-cost, high-margin Nevada producer is the Marigold Mine. Owned by SSR Mining (TSX:SSRM), Marigold stands out for its ultra low grades of .46 g/t. In production since 1989, Marigold is a large run-of-mine operation. After blasting the ore, it doesnt need to be crushed or ground and can go directly onto the leach pad which significantly reduces costs. In the third quarter Marigold reported an AISC of $965/oz, after realizing a gold price of $1,207/oz. Give me 1200$ AISC , with gold at 1500$ we have 300$ profit per ounce multiplied by a few million we still make it to 1 billion profit. POG is king.