to all, great thread... pardon my ignorance but every time i hear about this "hydrothermic event" it makes me think of the "carlin trend"..am i way off base here? was'nt carlins gold also deposited over a large area by pressurized water?

the deposits (hopefully) seem fairly similar to me unless there is some big difference i'm not aware of...you guys tell me, can i go around telling folks that gnh may have found the next carlin trend? please say yes..... :)

Carlin Trend

Goldstrike (Post-Betze) Mine in the Carlin Trend, the largest Carlin-type deposit in the world, containing more than 35,000,000 ounces gold. [5]

Gold was discovered in the vicinity of Carlin in Eureka County in the 1870s, but production was small. Placer deposits were discovered in 1907, but the deposits were too small to cause much excitement. It was not until 1961 that the Newmont Mining Corporation found the large low-grade gold deposit at Carlin that the mining industry began to take notice. The Carlin mine began producing gold in 1965, but at the price then of $35 per troy ounce, the ore grade was still too low to cause a rush to northern Nevada. It was not until the gold price shot up in the late 1970s that mining companies rushed to look for similar deposits.[6]

The Carlin Trend, part of what is also known as the Carlin Unconformity by geologists, is 5 miles (8.0 km) wide and 40 miles (64 km) long running northwest-southeast, has since produced more gold than any other mining district in the United States. The trend surpassed 50 million troy ounces (1,555 tonnes) of gold in 2002. The Carlin and other mines along the trend pioneered the method of open-pit mining with cyanide heap leach recovery that is today used at large low-grade gold mines worldwide.

New ore deposits are still being opened along the trend. The South Arturo deposit was discovered by Barrick Gold in 2005. The deposit contains an estimated 1.3 million ounces (40 tonnes) of gold.[7]

Carlin Unconformity

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Carlin Trend, shown with other alignments of sediment-hosted gold deposits in Nevada. Source: USGS

The Carlin Unconformity or Carlin Trend is a geologic feature in northeastern Nevada which represents a period of erosion or non-deposition likely associated with a collision between a tectonic crustal block called a terrane and the North American Plate. The collision occurred during the Mississippian Period, about 350 million years B.P. The collision is associated with the Antler Orogeny.[1]

The collision induced higher crustal temperatures and pressures which produced numerous hot springs along the suture zone. Several episodes of subsurface magmatism are known to have occurred subsequent to the collision, associated with tectonic forces affecting the entire Basin and Range. During each of these episodes, and particularly during the Eocene epoch, hot springs brought dissolved minerals toward the surface, precipitating them out along fissures.[2] Among these minerals were gold and silver.

The Carlin Gold trend is one of the world's richest gold mining districts. It is a belt of gold deposits, primarily in Paleozoic limy sediments, that is about 5 miles wide and 40 miles long, extending in a north-northwest direction through the town of Carlin, Nevada. Gold was first discovered in the area in the 1870s, but there was very little production until 1909, and only about 22,000 ounces was produced through 1964. By 2008, mines in the Carlin Trend had produced over 70 million ounces of gold, worth around US$85 billion at 2010 prices.[3]