Site hosted by Angelfire.com: Build your free website today!

Rocks In My Head

Blog Tools
Edit your Blog
Build a Blog
RSS Feed
View Profile
« April 2010 »
S M T W T F S
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30
Entries by Topic
All topics  «
geology et al
some days are pretty good
My own link
Rock Shop
You are not logged in. Log in
04/20/10
Minnesota precambrian
Ok, now I'm blogging about Minnesota geology.  There is an ongoing search for the original granitic crust, which is elusive.  It is possible it doesn't exist anymore.  It may have been eroded and recycled.  It's also possible that the original crust was basaltic.  One of the difficulties is that most of Minnesota is covered with glacial drift. The Canadian shield contains many belts of volcanic and  sedimentary rock.  It has been suggested that the belts are the uplifted remnants of the "basement", the structure upon which the volcanic-sedimentary features were built.  But that doesn't mean they are the original crust.
It is likely that the very early days of Minnesota were ones of violent volcanic activit

Posted by oh5/ojhoff at 8:26 AM CDT
Post Comment | Permalink | Share This Post

View Latest Entries