• Black Canyon of the Gunnison National Park

    Black Canyon Of The Gunnison

    National Park Colorado

Colorado Geology

National Park Service Mission

...to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.

Black Canyon of the Gunnison National Park and Curecanti National Recreation Area Outreach Education is committed to: Creating an awareness and fostering an appreciation for the mission of the National Park Service and the natural, cultural, and historic resources of Curecanti National Recreation Area and Black Canyon of the Gunnison National Park.


Curriculum enhancing activities designed to complement national and state content standards across a variety of disciplines.

Title: Colorado Geology

Theme: Colorado has a rich mining history; learning about the properties of rocks and minerals and the effect mining had and still has on Colorado can help us understand the geology of the state.

NPS focus: Public Law 39-535 (Organic Act),

Public Law 95-250 (Redwood National Park Expansion Act),

Vail Agenda Education Committee Report (Strategic Goal #2; Action Plan 16) and (Strategic Goal #3; Action Plan 52,62),

Curecanti and Black Canyon Themes: Natural Resources/Wildlife

Environmental concepts: Everything is connected to everything else (interrelationships).

Everything is going somewhere (cycles).

Everything is becoming something else (change).

Environmental learning hierarchy: Analogies, ecological principles, problem solving processes, decision making procedures

For an approximate class size of 24: Igneous rock (granite); metamorphic rock (quartz); sedimentary rock (sandstone); PowerPoint projector; laptop computer; 25' extension cord; mineral identification worksheets; minerals; 6 tiles; 6 4"X2" pieces of glass; 6 magnets; 6 pennies; 2 gold pans; fool's gold (pyrite)


Knowledge level:
Students will be able to verbally state the three different kinds of rocks and how they are formed.

Students will be able to define a rock and a mineral.

Comprehension level: Students will be able to verbally describe the effect geology had on Colorado history. Students will be able to verbally describe how rocks and minerals affect their lives.


Place several items (including a plastic spoon, a pencil, a binder clip, etc.) on the desk at the front of the room. Ask the students what all of these items have in common. (They are all products of geology!). Geology is important not just so that you can get a good grade in your fourth grade class, but it’s also important in our everyday lives. Our lives would be very different right now if we didn’t know about different minerals and use them like we do. For instance, the plastic chairs you’re sitting on—Poof! Gone. How did you get to school this morning? Bus, car, truck-gone, because they need petroleum (gas) to operate. You’d never ride in another car, never brush your teeth with toothpaste again, and at a fast food restaurant, you’d have to eat your sundae and salad with your hands, because plastic forks and spoons are made from minerals, too. Metals, plastics, and rubber products come from minerals, so most of the items that we use everyday, like pens, binders and other school supplies are geologic products. Minerals and geology are very, very important in our lives, so it’s great to have this opportunity to learn about them.

Who can tell me why they think that geology, the study of rocks and the earth, is especially important here in Colorado? Mining. Colorado has many types of minerals buried beneath its surface, and for hundreds of years, people have mined the land trying to get access to those minerals. Does everyone know what a diamond is? Tell me what you know about diamonds (very expensive, wedding rings, hardest mineral). Wouldn’t it be cool if there were diamonds right here in Colorado? Raise your hand if you think that there are diamonds in Colorado. Actually, Larimer County, Colorado, has the largest diamond mine in the United States. Colorado also has approximately fourteen coal mines, located across the state. Why is coal important? That’s right, it’s used to generate electricity—as a matter of fact, more than half of the United States’ electricity comes from coal. How many mines do you think are still operating nowadays in Colorado? (about 19). Mining is very important today in Colorado, but it was also a very important part of Colorado’s history.

Why do you think that people would go to so much trouble to get certain minerals out of the earth? That’s right, some of them are useful, and some are very valuable.

So if people are risking their lives and working really hard to extract minerals from the earth, then it must be pretty important that they know what they’re digging for, right? Imagine if someone claimed that they found gold on their land, and they spent hundreds of thousands of dollars building mines and buying heavy machinery and paying people to work in the mines, and then it turned out that all he really had was this mineral (show a piece of fool’s gold), Iron Pyrite, or fool’s gold. Fool’s gold isn’t worth nearly as much money as gold is, so the man would go bankrupt and he’d feel pretty ridiculous, too. So it’s important to know how to identify minerals and rocks.

Are people the only ones who use rocks and minerals? No, animals do too. Some may build their dens inside a cave, like a bear or a mountain lion. These animals depend on the rocks for their shelter and as part of their habitat. Moose and big horn sheep need minerals like salt and potassium in their diets, so they come to certain lakes to lick those minerals from the mud along the shoreline.

Speaking of rocks and minerals, who can tell me what the difference is between a rock and a mineral? The main difference is that a mineral is 'homogeneous,' which means that it is the same all the way through. If you look at a lump of salt under a microscope, every part of it has the same structure. But rock is not homogeneous; it is a mixture of two or more minerals. For example, granite, a rock, is made up of three minerals, mica, feldspar and quartz. So you may look at a rock and see lots of different colors and textures.

So if it’s true that rocks are made of minerals, how do the minerals join together to create rocks? There are three different categories of rocks, and the categories are based on how each type is formed. I’d like to show you some pictures to explain how the rocks are formed.

Slide show

Slide 1: The geology of Colorado is exciting, because we can see rocks that are billions of years old, and rocks of many shapes, sizes, and colors!

Slide 2: Do you remember the three different kinds of rock? Igneous, sedimentary, and metamorphic. Let’s see how each type is formed.

Slide 3: Igneous rocks are formed from molten magma or lava. The word igneous means "resembling fire". All igneous rock starts deep in the earth as hot, molten magma. Hot, liquid rock is called MAGMA when it is still inside the earth, but once it comes out through a volcano it is called LAVA.

Slide 4: If the magma cools and hardens inside the earth it is called "intrusive" rock. Intrusive rocks cool slowly and have large crystals, like the pegmatite that you see here. When the magma comes out of the earth's crust through a volcano, it is called "extrusive". It cools off quickly, and the crystals that form are very small. Here’s an example, called pumice, and another called obsidian, which looks like black glass and was used all the way back in the Stone Age to make tools and arrowheads. (Hold up an igneous rock).

Slide 5: Every minute of every day, rocks are being worn down by wind and rain. Tiny grains of sand, mud and clay are worn off and washed into streams, rivers, lakes and oceans. When these tiny bits of sand and dirt settle to the bottom of the water, they are called sediment. Minerals in the water and very tiny sea animals also get mixed in with the dirt and sand to form the sediment. Every day more sediment piles on top of what is already there. After thousands and millions of years we end up with a really deep pile of sediment. The weight and pressure from all the stuff on top turns the sediment on the bottom into sedimentary rock! (Hold up a sedimentary rock.)

Slide 6: Metamorphic rocks are formed when other kinds of rocks are changed by great heat and pressure inside the earth. The word "metamorphic" means changed. Think of metamorphic rocks as recycled rocks. When igneous, sedimentary or even metamorphic rocks get buried deep beneath the surface of the earth, over millions of years the heat and pressure inside the earth change them into something else. Limestone can be changed to marble, sandstone can be changed into quartzite, granite turns into gneiss, and shale can be changed to slate. It's just another example of how the earth is constantly changing! (Show an example of a metamorphic rock (quartz).) All three of these kinds of rocks are found at Curecanti NRA and Black Canyon of the Gunnison National Park.

Slide 7: Now, let’s take a step back in history and see how people in the past used rocks and minerals. Some Ute Indians spent their summers where Curecanti NRA is now located and on the rim of the Black Canyon. They used rocks and minerals for cooking, weapons and decorations.

Slide 8:
The area of Colorado we live in has a long history of mining. Gunnison, where Curecanti is located, lies on the Colorado Mineral Belt, which is a strip running from Denver to Durango, rich in silver, gold, lead, and other minerals. So, with all these minerals within reach, just under the surface of the ground, it makes sense that there would be a lot of mining here. It might have made sense, but that didn’t make mining any easier. This is the equipment that the old-time miners used to pan for gold, in a process called placer mining. This type of mining was inexpensive and one person could do it alone, without a team of people. Placer mining was common in the Gunnison area.

Slide 9:
The Gold Rush started with the discovery of gold in the Denver area in 1859. When all of these people rushed to Colorado to strike it rich, they needed a place to live. They didn’t have money or time to build sturdy houses, so instead they lived in Gold rush boomtowns, consisting of temporary tents. These boomtowns did not last long. They deteriorated as people realized that there was not enough mineral wealth to go around, and returned home where they’d try to make a living some other way.

Slide 10: People who were wealthier were able to go beyond placer mining and begin mining into the Rocky Mountains. This type of mining is called hard rock mining and is achieved by digging tunnels underground or into the mountains.

Slide 11: The hard rock miners used tools such as picks, shovels and dynamite. Children your age also worked in the mines. Why do you suppose they used people your age? Someone your size could fit into smaller places to load dynamite and get out faster than an adult. Hard rock mining was very dangerous work.

Slide 12:
Railroads were built to transport people and minerals. The Denver and Rio Grande Railroad went right through Curecanti and deep inside the Black Canyon.

Slide 13: Building the railroad was very hard work, just as the mining was. Many immigrants worked long, hard hours to create better transportation through the Rocky Mountains.

Slide 14: The railroad eventually came to an end when other means of transportation became more efficient. (picture of horses, the first car in Montrose, and more cars).

Slide 15: The study of rocks and minerals is still important in Colorado, although the days of gold rushes and boomtowns are long gone. Now let’s look at some examples of rock formations in and around Curecanti and the Black Canyon. Based on what you’ve learned, what type of rock is this? It's a sedimentary rock.

Slide 16: This is another example of sedimentary rock. How can you tell? You can see the different layers within it.

Slide 17: This specific section of rock is called the Morrison Formation. Many fossils are found in this layer of rock. Fossils of dinosaurs have been found in Curecanti, within the Morrison Formation, above the shoreline of Blue Mesa Reservoir.

Slide 18: This is an example of metamorphic rock, or rock that has been altered by heat and pressure.

Slide 19: What is molten rock called when it is underground? Magma. When it is above ground, it is called lava. What type of rock is formed by volcanic activity? It’s called igneous rock, which can look very different, depending on where the magma or lava solidifies. These are both examples of igneous rock, even though they look very different from each other.

Slide 20: Many National Parks have been created to protect the geologic features of an area. One of the many important things the National Park Service does is preserve the natural and geologic features of the United States.


See section III.


Mineral Identification

So now we know that rocks and minerals have been important for a long time. The cave people used stones to make tools and Native Americans have used rocks and minerals for weapons and even for decorations for thousands of years. And geology is still important today. That’s why today we’re going to show you some tests that geologists, or people who study rocks and the earth, use to identify minerals.

Divide the class into four groups. Give each group a tile, file, penny, magnet, piece of glass, and one mineral sample. Each group member should be given a worksheet. "Each group is going to try to identify a variety of minerals, one at a time. We're going to be geologists, so first we'll determine the color of the mineral. Write down one or two words to describe the color, in the first column. Next, test the luster, or how shiny a mineral is. If it’s shiny like a quarter, geologists say it's metallic. If it’s not shiny like a quarter, they call it non-metallic. If it’s clear and looks like a piece of glass, it’s called glassy. Another test is for magnetism. Who knows what it means if something is magnetic? We can use a magnet to determine which minerals are magnetic. Another way to distinguish between two minerals is based on the color of its streak, when it’s scraped against a white tile. And last but not least, we’ll identify minerals based on their hardness, using Moh's scale of hardness. (Make a small diagram on the board showing 10=hardest=diamond on the top and 1=talc=softest near the bottom, and a line connecting the two. Along the line, mark 2.5=fingernail, 3.5=penny, and 5.5=glass). Who knows what the hardest mineral is? It’s the diamond, which ranks 10 on the hardness scale. The softest mineral is called talc, and it’s a 1 on the hardness scale. So we know that this mineral that we’re testing is bigger than 1 and smaller than 10. How do we narrow it down? First, we'll scrape the mineral on our fingernail. If it scratches the nail, then the mineral is harder than the nail, which is 2.5 on the scale. If it's harder than the nail, then scratch it on a penny. If it's not harder than a penny, then write 3 in the square under hardness. If it does scratch the penny, it’s harder than 3.5. Then scrape the mineral against a piece of glass. If it scratches the glass, the mineral is harder than 5.5, so you can write >5.5 in the box. When you have finished doing these tests on a mineral, you will be able to identify it by using the mineral key on the back side of your worksheet. Then we'll give you another mineral to try to identify, using the same tests." Help students complete the tests and determine what minerals they have.

Check for Student Understanding: "Why did we do this activity? What is so important about identifying minerals? If we know the properties of certain minerals then we can know how to use them, where they came from and we can also develop new uses. Some minerals and rocks are great for construction, and others are great for jewelry making. Each mineral has its own unique set of properties.


Students can look around their schoolyard and home to find different objects made from rocks and minerals.


We’ve learned a lot about the values and uses of minerals, so I have a question for you. Do you think that it’s always a great idea to mine the minerals and remove them from the ground? Who else might mining have an impact on? The plants and the animals who live in the area. Their homes might be destroyed. If we mine all of the oil in the world, since it’s non-renewable, once it’s gone, it’s gone forever. We need to be careful when we mine, and think before we decide to dig up the earth searching for minerals. Some mineral deposits are better left alone.

We hope you learned a lot about geology today and how it relates to your life, everyday! Come and visit us at the BLCA or Curecanti to explore some more fascinating geology. Thank you!

VIII. Self Evaluation

Indicate what you judge to have been the strengths of the lesson, what changes you made during the lesson and what changes you would make if you were to teach the unit again.

Did You Know?

Upper Black Canyon/Morrow Point Reservoir

The Black Canyon stretches far beyond the 14 miles within the national park. Including the canyon within Curecanti National Recreation Area and Gunnison Gorge National Conservation Area, the total length is 53 miles.