The Tartan

Much of Pittsburgh’s history has been shaped by its geology. The local abundance of coal gave the region its wealth and was the driver of Pittsburgh’s development as a major city. This natural occurrence is even the foundation, albeit indirectly, of Carnegie Mellon, so the questions arise: How did the coal get here in the first place, and why was it so influential?

The coal basin, mined in and around Pittsburgh, stretches about 11,000 square miles and is part of the Appalachian Basin coal region — specifically, it is called the Upper Pennsylvanian Pittsburgh coal bed. Today, Pennsylvania and West Virginia make up the second-largest coal-producing region in America, providing 27 percent of all the nation’s coal. 

Many large-scale geological processes happened to produce and deposit the coal that humans then extracted. One such process was tectonic plate movement. Scientists posit that the most influential geological event in southwestern Pennsylvania happened about 300 million years ago before homo sapiens even existed. At this time, the African and North American tectonic plates collided to form Pangea, pushing up the Appalachian mountains along the border of the North American plate. About 100 million years later, the plates would separate again and form the Atlantic Ocean between them.

Another major geological event that impacted Pittsburgh’s topography is the ice age. Pittsburgh has actually never been covered by glaciers, but in the most recent ice age, the ice’s edge came within about 30 miles north of the city. As these massive glaciers melted, the water, sand, and gravel that flowed out of them completely changed the landscape of Pittsburgh. 

Some paths for water became more favorable, such as the river paths that we now know as the Monongahela, Allegheny, and Ohio Rivers. Other channels where rivers had previously flowed became blocked by glacial deposits, leaving empty valleys that were suddenly dry. These channels eventually became habitable and today some of them are homes to landmarks such as the University of Pittsburgh’s Cathedral of Learning.

These factors combined meant that the Pittsburgh region had a very old and tumultuous geological history in which one of the most valuable substances formed underground: coal. People first began mining coal in Pittsburgh in the 1750s on Mount Washington. In the early 19th century, economic factors made coal especially desirable over the alternative energy source of wood. The price of one unit of wood was two dollars in 1809 — in the same year, the price of one unit of coal was six cents. 

Coal’s inexpensiveness, its abundance in the region, and the three rivers in Pittsburgh that allowed the transport of goods all combined to allow Pittsburgh’s economy and political strength to grow like never before. As transit technology improved and railroads became more sophisticated throughout the 19th century, Pittsburgh’s coal exports grew along with it, creating a period of incredible opportunity for the city.

By the mid-19th century, coke became important alongside coal. Coke is a substance made by burning coal and is effective for powering industrial furnaces. But in the mid-20th century, after the Great Depression and the major economic changes brought about by World War II, the coke and coal industries began to fall out of favor. 

Today, researchers estimate that there are about 14 billion tons of coal left in the Pittsburgh coal bed out of the original 31 billion tons. However, most of this coal is very hard to reach and materials such as natural gas are more favorable, so this coal reserve will most likely stay untouched. 

The story of coal in Pittsburgh reminds us that when we go to turn on our lights or heat our homes, we are using the power that the Earth created eons before humanity ever existed. This serves as a reminder that we owe our lives and lifestyles to those who came before us, even if we’re just thanking the dinosaurs.