The Carlin Unconformity, also known as the Carlin Trend, is a geological feature in northeastern Nevada resulting from a collision between a terrane and the North American Plate during the Mississippian Period, approximately 350 million years ago. This collision led to increased crustal temperatures and pressures, causing hot springs to emerge along the suture zone. Subsequent episodes of subsurface magmatism, particularly during the Eocene epoch, brought dissolved minerals, including gold and silver, to the surface, creating the Carlin Gold trend.
The Carlin Gold trend is a significant gold mining district, spanning about 5 miles wide and 40 miles long, primarily in Paleozoic limy sediments. Gold was initially discovered in the 1870s, with limited production until 1909. However, by 2008, the mines in the Carlin Trend had yielded over 70 million ounces of gold, valued at approximately $85 billion at 2010 prices.