Geology and Politics

The other day I was on Facebook and one of my friends retweeted an image of a political map by county from the 2012 Election between Obama and Romney. The purpose of the original tweet was to highlight a curve of blue (democratic) counties in the southeast United States. Here is the original tweet:

A retweeted image that shows the results of the 2012 Presidential election. The tweet reads: "See blue belt on Obama?Romney map? That's Cretaceous coastline. Fertile soil later led to high cotton production + high slave population.

When I first saw this image, I was very intrigued, but I also wanted to check the accuracy as well as learn more about the geology. Below I am attaching a paleogeographic image of the Late Cretaceous shoreline from Google Earth provided by Ron Blakey.

This image shows North America during the Late Cretaceous (~90 Mya). 

If you are not familiar with looking at these paleogeographic maps, it may be difficult to visualize exactly where the shoreline is compared to the modern day North America. I am now going to attach another paleogeographic map from Ron Blakey's website that shows the paleogeography with outlines of the states, and I have approximately overlain the political map.

An image that shows an overlay of the 2012 political map and the paleogeography of North America in the Late Cretaceous (~85 mya).

The last Google Earth image I want to show is the location of Cretaceous rocks in the United States.

An image of the United States that shows the location of Cretaceous Rocks.

The previous images clearly show that the democratic votes line up well with the location of the Cretaceous shoreline! I didn't think the person who posted the tweet was lying, but it is fun to look for yourself!

I was also curious about why these soils are the best for cotton growth. According to an eHow website, cotton grows best in sandy loam soils or loamy sand soils that drain well and have a pH in the range of 5.8 to 8. Without getting too much into soil classification, sandy loam is approximately 60% sand, 10% clay, and 30% silt particles. Loamy sand is about 60% sand, 10% clay, and 30% silt. This site also mentions the color of soils but I won't get into that. If you are interested in reading more from this site, here is the link: http://www.ehow.com/list_6606124_types-soil-cotton-plants.html.

I hope I don't say this in any kind of bad way, but the south tends to vote republican, but the African American community tends to vote democratic. The sad part of the political image is that it implies that the people who lived and voted in those democratic areas are descendants of the slave population. This point was also obviously stated in the original tweet.