Homestake Open Pit, Lead, South Dakota by Ron Schott

The open pit at the top of the Homestake Gold Mine in Lead, South Dakota beautifully exposes a series of Tertiary rhyolite dikes that were the focus of the hydrothermal system that formed this rich gold deposit. The open pit is no longer active, but it is a great opportunity for geologists to get a glimpse into the uppermost crust of the Earth.

Note that when viewing this in Google Earth, I have placed it in a position that corresponds with the shooting location as seen in the current satellite imagery. Unfortunately, the digital elevation model and the satellite imagery are not well registered at this time, so although I took this GigaPan at the edge of the open pit, it appears to be quite a distance from the edge when one compares it with the topography in Google Earth.