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Spring 2011 • BAKKEN BREAKOUT By Dan Sharp for the Tribune

Photo courtesy of Lignite Energy Council

North Dakota’s economic success is due in part to our remarkable fossil fuel resources. This is how they got here.

No one who has endured a winter here has ever accused North Dakota of being tropical. Cold, windy, dark, snowy – no question, guilty as charged. But, “tropical North Dakota” is as oxymoronic as “icy hot,” “even odds” and “good grief.” It just does not roll off one’s tongue.

Yet our balmy past is what allows us to live and work in our often challenging climate. Driven by a global phenomenon called plate tectonics, an ancient North Dakota – often straddling the equator for millions of years on end – created just the right environment for the formation and accumulation of hydrocarbons. They are the coal, oil and

natural gas that fuel our homes and businesses and provide us with an economic base that is truly the envy of the entire country.

How did they get here, anyway – those hydrocarbons? And why are we so blessed when nearby states like South Dakota and Minnesota are so energy poor? The short answer, of course, is that we are very, very lucky. The long answer lies deeply hidden in key periods during the past 350 million years or so of North Dakota’s geologic history.

While coal, oil and natural gas are solid, liquid and gaseous, respectively, they have some surprising similarities. Being

hydrocarbon fuels, they are all direct by- products of living organisms that grew, crawled and swam in ancient swamps and shallow seas in our part of the planet. And, as every high school chemistry student knows, hydrocarbons are made up primarily of two elements – hydrogen and carbon. They share a gene pool with wood, asphalt, grains, sugar and many other everyday things that we consume in one way or the other.

Lignite – trees to electricity The debate as to whether lignite should or should not be called coal will never go away. It is more or less an argument of semantics. Lignite is a low-carbon fuel that just has not cooked long enough to develop into a more energy- packed rock like eastern bituminous coal or the sub-bituminous coal of Wyoming and Montana, the source of all those coal trains that amble through Bismarck.

Like all coals, lignite forms under predictable environmental conditions. It starts with the tremendous accumulation of plant materials in tropical or semitropical areas – swamps, marshes, lagoons, lakes and forests. As sea level rises or as the basins fill with water, those plants are submerged for thousands of years and thereby sheltered from atmospheric oxygen and subsequent rotting. The partially decomposed muck is called peat.

Erosion of nearby landmasses then smothers the submerged plant matter with layers of sand and mud known as overburden. This process might continue for hundreds of thousands, even millions of years. The weight of this sediment accumulation causes subsidence and deeper burial of the plant matter. Today, the Dismal Swamp in Virginia and the Okefenokee Swamp astride the Georgia- Florida state line are real-life examples of the early stages of coal formation.

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