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"mirage" <mjohnson37@xxxxxxxxxxxxx> wrote in message
news:1140928585.546741.193390@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> George wrote:
>>
>> The MOR spreading centers themselves, in a sense, are a sort of linear
>> hotspot. If you look carefully at spreading centers, such as the East
>> Pacific Rise, as shown in the link below:
>>
>> http://marineemlab.ucsd.edu/Projects/EPR2004/Plots/EPR_view3d1.jpg
>>
>> You will snote in that image that volcanoes form on the rise and then
>> are
>> carried off of it on either side through plate spreading (I suspect that
>> volcanoes similar to the ones discussed for Vancouver are likely to be
>> found on the ocean floor to the west of the spreading center there). I
>> think that is the same kind of mechanism that we are seeing in
>> Vancouver,
>> and I think this is different than what we see with Yellowstone. And
>> note
>> that usually with these sorts of spreading center volcanoes, as they
>> move
>> off the spreading center, they eventually become extinct. Yellowstone
>> is
>> located far from any recognized MOR, has erupted relatively little
>> oceanic
>> basalt, and certainly is not extinct. Though there may be an indirect
>> relationship with what has occurred off the west coast, I think the
>> Yellowstone hotspot has a different, though related, origin. I think
>> Yellowstone is more directly related to Basin and range geology than to
>> the
>> Pacific Northwest coast. But that is just my humble opinion, about
>> which I
>> reserve the right to change without notice. :-)
>>
>> Here is a link to a report published by Christiansen, et. al. on the
>> origin
>> of Yellowstone. Read particularly the conclusions, as they are germaine
>> to
>> this discussion:
>>
>> www.dur.ac.uk/g.r.foulger/Offprints/Yellowstone.pdf">http://www.dur.ac.uk/g.r.foulger/Offprints/Yellowstone.pdf
>>
>> George
>
> Thanks, George. Christiansen's report has me digging into new topics
> to understand it. This is fascinating and, for a novice, a clear
> pointer of how much there is to learn just to ask an intelligent
> question. Isn't it remarkable that what seems obvious at one level,
> doesn't make any sense at all when you know more. Thanks for your
> thoughts (and patience).
>
> mirage
You're most welcome. Just so you know, the origin of the Yellowstone
hotspot (and in some circles, whether it is even a hotspot) is still being
debated. There is a lot of fascinating ongoing research in this area and
other related areas. Stay tuned. The fat lady hasn't sung yet. Having
said that, Christiansen's report is very good, and raises a lot of critical
points, IMHO.
George
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