How 100-million year old geology affects modern presidential elections

The image above shows the outcome of the 2008 presidential elections in the American South. Counties that swung Republican are in red. Counties that swung Democratic are in blue. The result shows more than just the modern political landscape. In fact, the blue counties trace the outline of an ancient coastline, from a time when much of the South and Central-West parts of North America were inundated with shallow, tropical seas.

I love this article by Dr. M at the Deep Sea News blog, which explains the geologic history of these oceans and explains why an ancient sea would affect modern politics.

During the Cretaceous, 139-65 million years ago, shallow seas covered much of the southern United States. These tropical waters were productive–giving rise to tiny marine plankton with carbonate skeletons which overtime accumulated into massive chalk formations. The chalk, both alkaline and porous, lead to fertile and well-drained soils in a band, mirroring that ancient coastline and stretching across the now much drier South. This arc of rich and dark soils in Alabama has long been known as the Black Belt.

...Over time this rich soil produced an amazingly productive agricultural region, especially for cotton. In 1859 alone a harvest of over 4,000 cotton bales was not uncommon within the belt. And yet, just tens of miles north or south this harvest was rare. Of course this level of cotton production required extensive labor.

Read the rest of the story at Deep Sea News


  1. But what does it mean? People who have more fertile soil, have more food, thus are lesser assholes, chill more with a spliff, and [theoretically] vote for peace and freedom?

    1. People don’t eat cotton, but it is a labor intensive crop to harvest. Labor which was by and large provided by black slaves whose descendents still live in these areas and now vote overwhelmingly for Democrats.

    2. The article explains that the counties with more fertile soil were way more productive and thus required exponentially more slaves to work the land.  To this day, these counties are still predominantly black. And vote democrat. 

      What the article fails to explain is why the black people who live in these particular counties vote democrat more often than other southern black people. Is it a matter of concentration? Does any southern county, regardless of ancient coastlines, with a predominantly black population swing democrat?

      Anyone care to ‘splain it like I’m 5?

      1.  That’s pretty much it. See me there in Atlanta? Ok, I’m not black but much of Atlanta is. But I grew up in Northwest GA — the Scots-Irish mountains. No black people to speak of there. In fact, I didn’t have a black classmate until I entered college. My school pictures look like I grew up in Norway. Blacks across the South vote better than 95% Democratic so the only issue is who constitutes the majority population.

    3. I don’t know about a historical context, but I will say for NC that a good portion of the blue counties are also the counties with the largest cities and most population (including non-native residents). 

      Personally I think the 2008 election doesn’t necessarily give a good representation of the black/white/latino vs. conservative/democrat correlation.  I have heard and talked to several black people who have said they voted for Obama simply because he was black.  Obviously the Hope and Change points in his campaign helped, but it would be interesting to see an identical map to this come November.

  2. Huh. I’ve stared at Google maps for quite some time, wondering at the cause of the obviously fertile crescent that swings out of Mississippi through Alabama (my home state). Thank you so much for posting this. It makes quite a bit of sense.

    Also, in response to Digilante, I’m afraid it has something to do with socio-economic and historical forces in the South.

  3. That’s a nice piece. Alabama elections, and elections in the South as a whole, often changed patterns because of the so-called “Southern strategy,” among other things.

    Also, if you go to Google Maps and search for Wetumpka AL at the one-mile scale, looking to the southeast of the city will show you  a circular area that is the cause of one of the little blips in the Cretaceous Rock Units graph in the linked article: a large impact crater that altered local geology.

    I have been stuck in AL for the last year. Not much to do here, so I’ve been reading history books….

    1. Um, the map in the post above looks exactly like a composite of each state’s map in the second link you posted… EDIT: Well now I just look silly.

  4. That’s interesting stuff! Though now I’ll be on the lookout for anyone using “blue people” as a racist euphemism.

  5. Ok, but none of this seems to explain clearly WHY this happens. If at the end of the day the conclusion is that people vote along racial lines, then this article does not bring any new value to the discussion, so there must be something more interesting at play here. No?

  6. Somewhere between geology and politics: Calling this a ‘blue belt’ would only be valid since the 1980’s. IIRC the political colors before then were reversed- red for democrats and blue for republicans. I would love to know how that flip occurred.

    1. You’re not alone there, as the flipped colors confuse the hell out of any European used to Red being the left-wing/worker’s movement color.

  7. Interestingly, a similar study on the link between soil and electoral results was made in France in 1913, which more or less came up with the (extremely simplified) conclusion that “granit votes to the right, limestone votes to the left”. There aren’t many web articles in English on this study, unfortunately. The author’s name was André Siegfried, and his book was called “Tableau politique de la France de l’Ouest sous la Troisième République”.

    1. Since the Iron Age England has been divided into the north and the south as well, with the dividing line known to geologists as the Jurassic Way. You’ll probably find a lot of very old social and political divisions dependent on even older geological divisions. (Wasn’t there something about the recent Tunisian rebellion being divided on the same geographical divisions as the ancient Roman limes?)

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