Tuesday, April 16, 2013

The Mighty Miss

**** update 4/16/2013 ****

Have added Illinois, Alabama and Canada.  The latter thanks to Howard:

If you're not restricting yourself to south of the 49th parallel, here is an isopach map of the Western Canada Sedimentary Basin (WCSB): http://www.ags.gov.ab.ca/graphics/atlas/fg14_32.jpg
It's a total Carboniferous isopach (includes "Pennsylvanian" equivalents), but there isn't a whole lot of that in the WCSB--some in the northern end and smaller strips in the southern Rockies, so you could mostly use this as a proxy for "Mississippian".--Howard

Priority list (any help is greatly appreciated):
1. Missouri
2. Oklahoma
3. Texas
4. Nebraska
5. Kansas (Miss only, see note in original post)
6. Arkansas (unlikely this exists, so we plan to make one)

I like the Illinois map that shows an outcrop area, then isopach contours when it goes into the subsurface. So far, the thickest Mississippian section is about 12800 ft (3900 m) near Boise, Idaho.


State of the Mighty Miss project 4/16/2013. MArkUP study area in blue.

The 1979 USGS paper containing most of the maps is available in two parts: A-L M-DD


**** original post *****
Reading a classic USGS report I found several state contour maps showing thickness of the entire Mississippian section (Miss isopachs).  Since MArkUP is all about the Miss, I stitched the maps together in Google Earth for the big picture of Miss thickness.

The maps were rather ancient, but carefully compiled by excellent geologists.  Things did not quite match up at state boundaries and some were in feet with others metric, no matter.  Funny thing though, the states where I expected to get easy data are blank.


Miss isopach contour maps for some states, others needed. MArkUP study area in blue.

One would think it easy to find a Missouri map, where Miss outcrops aboud.  But the internet is silent for this.  Ditto for the other blank states, including my state of Arkansas.

If you can find a decent Miss isopach contour map in any graphics format, send me the file or a link.  I'll note contributors on updates of this blog post.

Thanks in advance.

ps. The Kansas isopach map is from top Arbuckle to top Miss.  In some parts of the state, this is all Mississippian rocks.  But not in other places.  So a true Miss isopach for Kansas would also be welcome.

1 comment:

Anonymous said...

If you're not restricting yourself to south of the 49th parallel, here is an isopach map of the Western Canada Sedimentary Basin (WCSB): http://www.ags.gov.ab.ca/graphics/atlas/fg14_32.jpg

It's a total Carboniferous isopach (includes "Pennsylvanian" equivalents), but there isn't a whole lot of that in the WCSB--some in the northern end and smaller strips in the southern Rockies, so you could mostly use this as a proxy for "Mississippian".

--Howard