Distribute the Fossil Fuels Distribution and Formation worksheet (S-6-2-1_Fossil Fuels Distribution and Formation and KEY.doc). Throughout class, monitor students as they complete the worksheet and provide feedback. “Last year you learned to identify fossil fuels. This year, we’re going to investigate the formation, production, and usage of fossil fuels. Let’s start with the term fuel. What is a fuel?” (A fuel is a material that can be converted to energy to do work.) “What are fossil fuels?” [Generally speaking, natural gas (like methane, ethane, and propane), petroleum (also referred to as crude oil and oil), and coal.]
Group students and distribute the Oil and Gas Fields of Pennsylvania map (S-6-2-1_ Oil and Gas Fields.pdf). Facilitate a class discussion of the map. “Now let’s take a look at fossil fuels in Pennsylvania. What does the title of this map tell you?” (the general location of crude oil and natural gas wells in Pennsylvania) “Examine the information in the explanation below the map. Use the color coding to interpret the map.” (Gas and oil wells are located in the western portion of Pennsylvania. Diagonal bands of color run northeast/southwest across the western portion of the state. The color banding shows a pattern of well depths: wells generally decrease in depth from the northwest to the southeast.) Hand out the Distribution of Pennsylvania Coals map (S-6-2-1_ Pennsylvania Coal.pdf). Facilitate a class discussion. “What does the title of this map tell you?” (The general location of coal in Pennsylvania.) “Examine the information in the explanation below the map. Use the color coding to interpret the map.” There are two kinds of coal found in Pennsylvania. Most coal is bituminous coal that is found in western Pennsylvania. There is very little anthracite coal in Pennsylvania, and it is found in the eastern part of the state. Note: The difference between the two types of coal will be explained later in the lesson.
“What can we say about the distribution of fossil fuels in Pennsylvania?” (They are located in the western part of the state.) “Let’s see why.”
Facilitate a short class discussion on changes in the Earth’s surface. “The continents have not always looked the same in Earth’s past as they do today.” Distribute the paleogeographic map set (S-6-2-1_ Paleogeographic Maps.doc) and the Geologic Time Scale (S-6-2-1_Geologic Time Scale.doc). “Find the Carboniferous Period on the Geologic Time Scale. Can anyone tell me why this period is called the Carboniferous Period? Lead students toward an understanding that coal and other fossil fuels are carbon based fuels from living organisms. The Carboniferous Period represents a time in geologic history that we get most of our coal and fossil fuels from. “Keep the dates in this timescale handy as we discuss the Paleographic Maps.”
Refer to an interactive geologic timescale for further information at http://www.enchantedlearning.com/subjects/Geologictime.html
Monitor students, providing feedback, during the discussion. “These maps are what we call paleogeographic maps—maps of how we think the surface of the Earth looked tens of thousands and even millions of years ago. Earth scientists constructed these models of the Earth’s surface using rock evidence collected from all over the Earth. Now order the maps according to age, left to right, oldest to youngest. Notice the map key. Ancient land masses are greenish to tan in color. Modern landmasses are outlined in white. Blue represents ancient oceans. We will not work with ice caps, glaciers, subduction zones, or sea floor spreading ridges today. The equator and the area of the present day Great Lakes is marked and labeled for you. You can locate what we now call Pennsylvania by looking directly south (on the three maps representing the more ancient appearance of the Earth’s surface) and directly east (on the map representing the most recent appearance of the Earth’s surface) of the Great Lakes area.”
Facilitate a short class discussion about sedimentary rocks. “Most rocks in Pennsylvania are sedimentary rocks.” Lead students to understand that sedimentary rocks commonly are made from the compaction and cementation of sediments—materials deposited in low areas by wind, water, ice, organisms, or chemical reactions. Sediments most commonly preserved are marine (ocean) sediments because they have a better chance of being buried and lithified (changed into sedimentary rock) and because oceans have covered most of the Earth’s surface throughout Earth’s history. “Many sedimentary rocks contain the remains of dead plants and animals, which are the source of crude oil and natural gas. So let’s look at the paleogeographic maps. When was the area we now call Pennsylvania covered by ancient oceans?” (From about 500 to 400 million years ago.) Note: Notice the ancient mountain ranges shown in the map of 425 million years ago. “Where were these ancient oceans located in relation to the equator?” (near or at the equator) “If the oceans were close to the equator, would the oceans be warm or cold?” (warm) “Fossils tell us that these warm oceans were shallow and filled with many organisms (like plankton, fish, corals, algae, and shellfish) that became the source for crude oil and natural gas formation.”
“How had the environment changed in what we now call western Pennsylvania by about 300 million years ago?” (It had become a land environment—it was no longer covered by an ocean—but it was still in a very warm climate since it remained near the equator.) Note: The rocks in the mountain ranges noted above were eroded rapidly. The resulting sediments were deposited by rivers and streams along the shoreline to the west, constructing a low-lying land area to the west of the mountains, between the mountains and the shallow ocean. See http://www.dcnr.state.pa.us/topogeo/education/es4.pdf pages 16 and 17 for an explanation and diagram. Compass directions refer to the present day orientation of the Pennsylvania area. “Fossils tell us that this region had become a low wet area—a swamp—with thick plant growth.” Facilitate a class discussion of coal forming processes, posting a bulleted sequence of processes (S-6-2-1_ Coal Formation Diagram.doc). Also, refer to http://geology.com/rocks/coal.shtml for pictures of peat, lignite, bituminous coal, and anthracite coal. Guide students in learning that, as the plants died, their remains were covered by water and buried by other plant remains. These layers of dead plant material accumulated first as peat (a porous brown mass of biologic material in which you can still see plant parts). With increased heat and compression accompanying continued burial by other layers of plants and plant remains, the peat layers turned into lignite (a very soft, brownish-black coal-like material). Burial to even greater depths with even higher temperatures changed the lignite into the bituminous coal (soft coal) shown on the Pennsylvania coals map. The coal beds in the eastern part of Pennsylvania were subjected to the forces of mountain building which further increased their depth of burial and temperature to which they were exposed, producing the anthracite coal (hard coal) beds associated with the mountains in eastern Pennsylvania.
Explain the next activity. “As a group, you will produce a graphic representation of coal-forming processes that includes: 1) a title; 2) a visual representation relating the formation of peat, lignite, bituminous coal, and anthracite coal to temperature, depth of burial, and time; 3) a legend explaining use of symbols, color coding, or pattern coding. You will then write a short narrative, based on your graphic, which explains coal-forming processes in terms of temperature, depth of burial, and time.”
Ungroup students. “Your last assignment is to write a short paragraph to answer the following question:
Are new sources for future crude oil and natural gas deposits accumulating in western Pennsylvania today? Explain your answer.
Your answer must include a yes/no response to the question in sentence form. Your explanation must include at least three supporting details for your answer in sentence form.”
Students who might need opportunities for additional learning can draw visual images of key terms that will assist them in remembering these vocabulary words and their meanings.
Students who may be going beyond the standards can create a Coal in the United States booklet that contains the following:
an introduction that includes information on the number of states that produce coal in the United States, the states that produce coal ranked according to coal production, and the three coal-producing regions in the United States.
a map showing the coal distribution in the United States.
a page for each of the three coal-producing regions in the United States composed of a title and a bulleted list of at least three important facts about the region.
One resource for this assignment is http://tonto.eia.doe.gov/kids/energy.cfm?page=coal_home-basics