Posted on 08/01/2018 10:54:18 AM PDT by ETL
Yep, I’m living on the New Madrid fault. It’s almost as if North America decided to split like Africa is at the Great Rift and then changed its mind.
The New Madred earthquake activity is associated with a really ancient fault (600+ million).
As the story goes, a pre-Pangea supercontinent known as Rhodinia split apart about that time and spreading later ceased there.
When large land masses break apart they do so along a 3-prong set of faults. Ultimately one of the three spreading centers ‘fails’ and the spreading continues along the other two.
This process is going on currently in the region around the Great Rift Valley in northeast Africa. The other two arms of the 3-prong system are the Red Sea and, I think, Gulf of Aden (spelling?).
Yes, I believe they have been showing this on public television about the formation of North America. I had wondered if New Madrid was somehow related to the end of the left side of the great fault.
Not sure what you mean by "end of the left side of the great fault". If, by 'left side', you mean the part of the US that was and still is west of the fault, it of course is still there, as that arm of the 3-prong fault never actually opened. It was/is a "failed" arm or failed rift. As spreading proceeded along the other two arms it stopped along the New Madrid arm. This was 600+ million years ago, during the breakup of early supercontinent Rhodinia. It was before supercontinent Pangea, which began breaking apart 'only' about 200 million years ago, eventuslly giving birth to the Atlantic Ocean. North and South America had been stuck to Africa at that time, and was South of the equator.
The PBS broadcast has been showing a great upside down magma red U starting in the upper midwest, curving over the great lakes and coming back down east of the great lakes. The end point showed on the left side was above the New Madrid area by hundreds of miles. The 600 mya you quote is also their figure, and they did refer to it as a failed rift. That is all I know. Hope you can find the broadcast some time, I have seen it twice in the past 2 weeks, don’t remember the exact name. Perhaps “Building North America” or something like that? I am 80 and memory not as good as when younger.
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