Saganagan Orogeny

The Saganagan Orogeny occurred during the Archaean Eon some 3.5 Bya (billion years ago). 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 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 Era.

End of Archaean Eon

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

See also

Saganaga Lake Saganaga Lake, Ontario