Coal supplies 2/5 of the world’s electricity demands. Coal is often called a “fossil fuel” because it was formed from the remains of vegetation up to 400 million years old. As trees and plants died in

Coal supplies 2/5 of the world’s electricity demands. Coal is often called a “fossil fuel” because it was formed from the remains of vegetation up to 400 million years old. As trees and plants died in forested swamps, they sank and accumulated in an anoxic environment (like the modern Okefenokee Swamp of Georgia). The decaying plants were subsequently buried by silt, sand, and other matter as the depositional environment changed slowly over time. There are four stages in coal formation: peat, lignite, bituminous, and anthracite. The stage depends on the conditions to which the plant remains are subjected after burial; the higher the pressure (and heat), the higher the rank of coal. High-ranking coal (i.e., anthracite) is denser and contains less moisture and gases than low-ranking coal (i.e., bituminous).

1. When comparing samples of bituminous coal (56) and anthracite coal (75), use the streak plate and wire nail to test for differences in streak color and hardness. Compare sample luster. In what ways are these samples different? In what ways are they similar?
2. Figure 2 shows where coal is currently found in Pennsylvania. According to the principles of original horizontality and lateral continuity, coal deposits once covered this entire region. Why does the map show ‘breaks’ – areas where no coal is found – in the coalfields? *consider the structural geology of the areas depicted in Figure 1)
3. a. In what physiographic province are the anthracite coalfields located? (see Figure 3). ____________________________________________________________________________________                   b. In what physiographic province is the main bituminous coalfield located? (see Figure 3).
4. a. Refer to Figure 4 *In the Explanation Section*. What are the ages of the rocks in Schuylkill County, east-central Pennsylvania? _____________________________________________________________                                                       b. Refer to Figure 4 *In the Explanation Section*. What are the ages of the rocks in Clearfield County, central Pennsylvania?
5. a. What is the age of the coal in Schuylkill County?  _____________________________________         b. What is the age of the coal in Clearfield County?  _____________________________________
6. Review your answers to questions 3-5. Summarize the similarities and discuss the different geological processes that controlled the distribution of anthracite versus bituminous coal in Pennsylvania.
7. Consider the bedrock patterns in Figure 1 and Figure 4. Sketch a generic cross section through the main bituminous coalfield to show how it is structurally different from the anthracite fields.