Knowledge enhancer round seven

On this fine first week of September we would like to share some local knowledge about the geologic history of this mighty basin... As it literally serves as the foundation to our enjoyment on the cool, pristine, fresh waters.



Were you aware?
Lake Superior rests mostly on Precambrian rock at the southern edge of the Canadian shield, the largest exposure of such bedrock on the planet.



Some of the world's oldest rocks, about 2.7 billion years of age, can be found on the Ontario shore of Lake Superior.




Lake Superior has its origins in the North American Mid-Continent Rift of 1.1 to 1.2 billion years ago, which produced a huge plume of hot mantle where the present lake sits. The crust tore apart, leaving an arc-shaped scar stretching form Kansas through Minnesota, then down to Michigan.



Within its borders, Lake Superior has both the thickest, and nearly the thinnest, crust found anywhere in North America not only that but it also is one of the earth's youngest major features, at only about 10,000 years of age--dating to the last glacial retreat. By comparison, the earth's second largest lake (by surface area, and largest by volume), Lake Baikal in Russia, is 25 million years old.

Gracias geologic glory!!!



Keep the knowledge enhanced, the appreciation for the lake fueled, along with days filled with health, happiness and laughter...

& Be sure on all your rock hunting excursions you take a map and compass. Ralphie loves rocks more than he loves lost people. Stay found and keep Mr. Schwartz Esq. proud...