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The Cliff Mine was the first copper mine in Michigan that paid dividends to its owners. This demonstrated that money could be made from the syncline caused by some of the oldest rocks in the world.The place I have selected is the spring,where water emanated and was used to wash the stampings. The question is – is this an adit or a spring? An adit was man-made, and used to empty water out of a mine that was collecting it. A spring is a natural conduit of water out of rock. Paths are marked.
Earth Cache The Cliff Mine – Historical site The Cliff Mine was the first copper mine in Michigan that paid dividends to its owners. This demonstrated that money could be made from the syncline caused by some of the oldest rocks in the world. What happened at Cliff? About a billion or so years ago, Michigan contained a giant volcanic rift, that erupted and produced lava http://www.minsocam.org/msa/collectors_corner/vft/mi2a.htm After the eruption, erosion took place, and the cooled lava (basalt) was covered with smaller rock pieces as erosion occurred. Another eruption laid more lava over this, followed by another layer of rubble. As layers covered layers, the rubble was compressed to form conglomorate rock. There are over 20 layers in this, the largest lava flow in the world. Eventually, the tectonic plates began to grind together. The rift wanted to close, but the center was heavier than the edges (due to the additional layers). Ultimately, the edges of the flow ripped apart, and the outer edges then slid under the edges of the bowl. This left a steep cliff on the left, at Isle Royale, and on the right, at the Keweenaw peninsula. The oldest rock can be found at the base of the cliff. At some time in this process, the layers in the syncline became suffused with a high temperature, high pressure copper solution. As with a giant chromatography (HPLC) machine, this solution cooled and reduced in pressure, and pure copper precipitated out of the solution wherever the solution had penetrated. Copper remained trapped in cracks in the rock, as well as small bubbles in the Basalt, and spaces in the conglomorate rock. Cliff as seen from the entrance 47°22'19.78"N, 88°18'45.79"W There are wood planks to help you over the streams In 1837, Michigan became a State, and was awarded the Upper Peninsula as compensation for the Toledo strip, which went to Ohio. Ten years later, the Cliff mine was extracting large lumps of copper from the earth, and finding that copper could be extracted from rock layers by crushing the rock. What remains at Cliff? Many of the miners who came were from Cornwall in England. These miners, displaced from home, went to South Africa, Australia, Chile, Cuba, and the Keweenaw, in search of jobs which used their mining skills. They built stone edifices, most notably engine houses and round (chimney) stacks, all over the world. The remains of these still stand at Cliff. The Stamp mill, where rock was stamped with automated hammers to release the copper, was a recent subject of excavation by Michigan tech archeology students. Unfortunately, all the excavation work had to be covered up ate the end of the excavation, to preserve the wood. The place I have selected is the spring, where water emanated and was used to wash the stampings, so that the light weight rock would be carried away, and the fine pieces of dense copper (“fines”) would collect at the bottom of trenches, to be harvested and sent for smelting. There is one historic mention of using water to power the stamps, using an undershot water wheel as happens in Cornwall, but no physical evidence remains. The question is – is this an adit or a spring? An adit was man-made, and used to empty water out of a mine that was collecting it. A spring is a natural conduit of water out of rock. The engine house is situated between the mine and the stamp mill, and presumably power was supplied to both. There are trails around the site, and also large poor-rock ( discarded as having not much copper) piles. The site is owned by the Keweenaw County Road Commission, who look on the piles of poor-rock as source for gravel for the roads. They periodically turn over surface layers of the piles, so that mineral specimens can be found by rock enthusiasts. They support historical and rock-hound activities on their land, as long as they are not actively on the site. “Closed to the public when Keweenaw County Road Commission or its subcontractors are actively using the site”. They also ask that large groups, archeology projects, etc. contact them ahead of time to seek permission. The linked web page https://www.louisewilson.net/CliffMineproject/Cliff_mine_project.htm includes some high-school level project ideas for statistics explorations. (link updated on 5/31/2020. Sorry about that).
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