User:Bettymnz4/Saganagan Orogeny

I moved this article out of the main Wikipedia because, as I was doing additional research to flesh out the article, I found a second date for it. Most of the references have it in the 2800 million year ago time period, just prior to the Algoman Orogenty (3/20/10 - I'm working on that now at one of my user pages). A few references show the 3800 million year ago date. So, until I have time to resolve the issue, I decided to move it.

The Saganagan Orogeny occurred during the Archaean Eon some. The mountains uplifted by this orogeny are in the area of the international border between Minnesota, U.S., and Ontario, Canada, in the vicinity of the Rove Formation. These mountains have completely eroded and the remnants are buried by sediments from later erosions.

Beginning of Archaean Eon
During the Archaean Eon Earth's interior was probably about three times hotter than it is today; there was a higher concentration of radioactive isotopes, plus the residual heat from Earth's accretion contributed to this heat. The additional heat flow probably caused the mantle to be more fluid than today and the crust much thinner.

Protocontinents
It is theorized that there were multiple small continental crustal pieces, called protocontinents, which were probably less than 500 km in diameter. The collision of at least two of these probably created the Saganagan Mountains.

The theorized first supercontinent, Vaalbara, existed during the early Archaean Eon.

End of Archaean Eon
By the end of the Archaean Eon heat flows fell to two times current levels.