What’s your favorite great lake? Lake Superior, of course! Where did it come from? It’s not a coincidence that Lake Superior is shaped the way it is. The previous #ThrowbackThursday posts are a great hint as to how our great lake was created. First, starting a billion years ago, the midcontinental rift that was ripping apart the super continent Rodinia created a heavy, layered mat of basalts (you can see the area of the rift as a red arch on the map below). These basalts slowly sagged into the earth under their immense weight. Zooming ahead nearly a billion years, several periods of glaciation carved the basalts and the softer sediments to further shape the basin. The last glaciers left only around 9,000 years ago. These melting glaciers filled the previously created “tub” with fresh water. And voila! Lake Superior! Of course this is a simplified version of the events, but you can learn more about Lake Superior and its creation at: geo.mtu.edu/~raman/SilverI/Lake/Welcome.html
Posted on: Thu, 31 Jul 2014 13:00:00 +0000
Trending Topics
Recently Viewed Topics
© 2015