Birmingham became the magic city thanks to an ancient bacteria

This story is part of the seventh AL.com series “Ancient alabama“, examining the natural forces that made Alabama what it is for the past 500 million years, and how those forces still shape the state today.

Every October, Birmingham’s Sloss Furnace Park transforms into one of the South’s most popular haunted houses, where costumed teens step out from the shadows to terrify patrons, who pay dearly to scare each other.

Wandering alone through the long shuttered ironwork on a cold November morning makes you wonder if all of that hassle is even necessary.

The place is pretty scary on its own, with no fake blood or spider webs. No chainsaw or hockey mask is as ominous as the echoes of empty hallways where thousands of men once sweated and bled to turn red rocks from a nearby hill into materials that could build skyscrapers in the city. booming below.

Birmingham’s Sloss Ovens are now a museum showcasing the city’s industrial roots.Graphic by Ramsey Archibald

Birmingham was nothing in the 1860s, just farmland and farms, until a group of industrialists created the city from scratch, thanks to its place on a railroad and its proximity to the three ingredients needed to make steel – iron ore, coal and limestone.

It was a huge success.

The city was founded in 1871, and less than 40 years later Birmingham had a thriving steel industry and was the booming city of its time. The downtown intersection of 1st Ave North and 20th Street has been dubbed the “heaviest corner of the earth” after four of the tallest buildings in the south were built there in 1912.

Birmingham was called the Magic City for its unlikely and rapid growth during this period, but it was not magic.

Instead, the city itself was the result of a series of geological events that began to unfold over 400 million years ago, providing all the ingredients to create and maintain the largest city. early 20th century southern steel industry.

Sloss Kilns National Historic Site

View of Birmingham city center from Red Mountain.

Iron and lime

The history of Birmingham’s steel industry does not begin with an industrialist or a railroad, but with sediment on the ocean floor around 443 million years ago.

The land beneath Birmingham was then underwater, collecting runoff from the handful of mountains advancing east. Some of this runoff mixed with lime-containing plankton shells and other marine life to form limestone.

Some of it turned into a thick slime that eventually turned into an iron ore called hematite, possibly with the help of some prehistoric bacteria.

Jim Lacefield, a retired professor at the University of North Alabama and author of the book “Lost Worlds in Alabama Rocks”, said the mud was believed to have been a greenish clay material lying on the ocean floor. These clays are said to already have a high iron content thanks to the erosion of mountains and volcanoes to the east in present-day Georgia, but they have received an additional boost thanks to local bacteria.

Lacefield said the best evidence we have suggests that these bacteria added oxygen to seawater, causing suspended iron to precipitate in seawater and the sediment to join at the bottom.

This process formed hematite, which is the official mineral for the state of Alabama due to its economic importance. He also gave Red Mountain, overlooking Birmingham city center, its color and name.

This hematite formed in veins sometimes 30 feet thick throughout Red Mountain, making it easier and more cost effective to mine. It is estimated that 300 million tons of rich iron ore were mined from the mountain’s “Big Seam” along the top of the mountain.

No new hematite is forming today, Lacefield said, because this old bacteria is no longer there.

And Birmingham’s iron ores had another special ingredient: limestone shells of plankton, snails, and other marine life that mixed with the rocks.

Usually, steelmakers add limestone to iron ore to “melt” it or remove impurities from it during the smelting process. However, Birmingham’s iron ore already contained enough limestone inside that little or no additional limestone was needed, Lacefield said.

The “self-melting” ore was perfect, even magical.

Charcoal completes the recipe

The iron ore and limestone dated back to when much of Alabama lay under a shallow ocean. But the coal arrived about 100 million years later.

By that time, much of Alabama had risen above sea level, but the state’s coastline was not where you might guess. At that time, about 323 million years ago, an ocean covered the northwestern part of the state, from what is now the Shoal Region south to Tuscaloosa.

The area between this sea and the young Appalachian mountains would have been covered with coal marshes – wet river deltas with 130-foot trees and huge insects and amphibians.

The decaying remains of these fertile swamp forests have become the coal fields of Alabama, especially in Jefferson, Walker, and Tuscaloosa counties.

City built on steel

Once the iron ore was found in Birmingham, the city needed one more ingredient to take off: people.

When the mines and kilns first opened, thousands of new residents flocked to the city from the United States and other countries as well. Residents of Alabama’s black belt agrarian areas have also moved to Birmingham in search of new life.

Not all came by choice. The civil war was over and slavery was over. But Alabama used a convict rental program at the time to supply more workers for mines and steelworks, and more than 90 percent of convicts sent to do forced labor were black. Critics called the system “slavery by another nameAs the state and industrial operations took advantage of cheap labor.

Sloss Kilns National Historic Site

Convict labor was used in many early Birmingham industrial operations.

The largest iron and steel companies built their own corporate cities, where housing, shopping, medical care, entertainment, and sports teams were all operated by corporations.

A lasting legacy

Iron mining in Birmingham continued until the early 1970s. By this time the industry had started to slow down, but the air in Jones Valley was still laden with pollution, a layer of smog visible from the top of Red Mountain.

Former company towns and other neighborhoods closest to coke factories and other large industrial facilities still in operation bear witness to decades of heavy industry.

In 2011, the US Environmental Protection Agency began investigating pollution in three neighborhoods in north Birmingham, ultimately designating the area as the site of the 35th Avenue Superfund due to high levels of contamination in soil by substances such as benzo (a) pyrene, arsenic and lead. .

The EPA has spent millions of dollars removing soil from the most contaminated properties over the past decade, even as some industries and officials battled their efforts to test and remediate the soil.

North Birmingham 35th Avenue Superfund site

Contractors working for the United States Environmental Protection Agency work to remove contaminated soil from a residence in the Collegeville neighborhood of Birmingham, Ala., August 22, 2018. The cleanup is part of the Disposal measures underway at the EPA site on 35th Avenue, which spans three neighborhoods in north Birmingham. (Dennis Pillion | [email protected])Dennis Pillion | [email protected]

Today many steel mills and furnaces have closed, but a few are still in operation.

Birmingham is now a medical hub, but it was all built on a foundation of iron and steel, a plan devised by 19th century steel barons to create ‘Pittsburgh of the South’. And these plans were only possible because of ancient bacteria and mud from 400 million years ago.

So the next time someone tells you Birmingham is the Magic City, you can say no.

This is just the place where three major geological events practically (sometimes literally) happened on top of each other, with mud and plankton creating limestone, then clay and bacteria creating iron ore. , and tropical swamps being compressed into charcoal.

Birmingham’s steel industry may have seemed to come into being overnight, but it actually took 400 million years to develop.

The next time…

In the next episode of Ancient Alabama, we’ll take a closer look at these 300-million-year-old coal bogs, where the remnants of ancient vegetation have become a key energy source for an industrializing Alabama.

Oldest Alabama

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