Earth Sciences - Eva Varga

In January, the U.S. Department of Agriculture (USDA) began its celebration of the International Year of Soils to highlight the importance of healthy soils for food security, ecosystem functions, and resilient farms and ranches.

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Healthy soils are the foundation of agriculture. In the face of mounting challenges such as a growing global population, climate change, and extreme weather events, soil health is critical to our future. Healthy soil is essential as global demands rise for food, fuel, and fiber. Soils also play a crucial role in food security, hunger eradication, climate change adaptation, poverty reduction, and sustainable development.

“Soil conservation is important because if we do not produce food , we do not eat.”

Over the course of the year, the Soil Science Society of America (SSSA) and other partners, will impart the importance of soil via monthly themes. Along with resource specialists and educators around the world, I will share with you the lessons and activities that I use with my own children. It is my hope that you find inspiration and resources to integrate these soil science lessons into your homeschool curriculum.

To begin, I have created this post as a means of sharing with you the print and online resources that I will be using with my students. This page will be updated periodically as we progress in our studies.

Print Resources for All Ages

Did you ever consider that with no soil there would be no life? Know Soil, Know Life will introduce you to an amazing world—the world beneath your feet. Published by the American Society of Agronomy, it provides a solid foundation about the world of soils. It is perfect for anyone desiring to know more about soil ecology. High school or undergraduate students will find Know Soil, Know Life is an easily accessible resource, but this book is for all ages. Everyone interested in being more environmentally conscious—the urban dweller, the young naturalist, the home gardener—can learn about the diversity of soils and their importance in our environment.

“We speak a lot of the importance of sustainable food systems for healthy lives. Well, it starts with soils.” ~ José Graziano da Silva, FAO Director-General

Also published by the American Society of Agronomy, SOIL! Get the Inside Scoop, provides a strong introduction to soil science for elementary students. Excellent descriptions of soil composition, importance of soil in the environment, and types of soil. This 36-page, full-color book explores how soil is part of our life ~ the food we eat, the air we breathe, the water we drink, and even the houses in which we live. The clear photographs and clear graphics enhance the text. The voices of actual scientists discussing the importance of soil scientists speaking directly to students brings the message of soil conservation home.

“The multiple roles of soils often go unnoticed. Soils don’t have a voice, and few people speak out for them. They are our silent ally in food production.” ~ José Graziano da Silva, FAO Director-General

Another fabulous resources is Life in a Bucket of Soil (Dover Children’s Science Books) by Alvin and Virginia Silverstein. The text and illustrations combine to introduce middle school students to the world of soil. I selected this one as our unit study spine and will be using it as guide as we undertake numerous hands-on activities.

Though this is a revised edition of the original 1972 publication, it is an excellent resource for homeschool. I particularly love that the illustrations are simple enough that we can utilize them as guides for our own nature journal entries. I’ve learned over the years that kids sometimes need examples to help them with their own illustrations.

Online Resources & Lesson Plans

In February, the theme is Soils Support Urban Life. Join me as I share lesson plans and activities to explore how rain gardens, living roofs, and composting can improve soil ecology – Do Your Part with Rain Gardens & Composting.

The March theme is Soils Support Agriculture. In my post, I share ideas to integrate writing and a contest sponsored by the California Foundation for Agriculture in the Classroom.

In April, I will share lessons and activities to teach students how Soils Clean and Capture Water. In May, the theme is Soils Support Buildings & Infrastructure.

For further soil ecology resources consider some of my earlier posts:

Science Career Options: Hydrogeology – Consider a field trip to a hydrogeologist office near you
The Rock Cycle – Lesson plan and free printables to learn about the rock cycle
Geospheres & Our Earth Systems – Activities integrating geosciences, technology, and art for middle school
Soil Erosion Experiment – As a part of a unit study on Africa years ago, we explored how different soils effect erosion
Field, Forest, and Stream – A series of three posts describing the outdoor ecology experiences we engaged in with STEM Club last year
Getting to Know the Millipede – One of the many invertebrates that live in our soils

My son has been fascinated with planes, ships, and trains for as long as we can remember. What boy isn’t, right? He has expressed interest in working for Maersk and even has a blog where he writes about his passions, A Boy & His Trains.

When we were in the Galápagos, he would often wake before the rest of us and wander about the ship on his own accord. If he wasn’t in his cabin or on deck with one of the other passengers (he really connected with Gary – an older gentleman from Alaska who shared many similar interests), he could be found on the bridge with the Captain.

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OhCaptain

I loved that he had the freedom to explore the Evolution and that the crew was willing to take him under their wing. He learned a lot about navigation on our voyage. I was sure to expand on this real life experience with the help of North Star Geography.

Navigation

Explorers have always used the night skies to measure latitude by measuring how many degrees above the horizon the North Star (Polaris) appeared. Below the equator, Polaris is no longer visible, and the constellation known as the Southern Cross must be used instead.

Knowing your position and direction are key parts of navigation. It is also important to establish your route. Which route is best? Where do you turn?

As a Brand Ambassador for Bright Ideas Press we have received a complimentary copy of North Star Geography in exchange for our honest insights about how this program is working in real life with our family.

Tools of the Trade

Tools for measuring position have changed dramatically since the first explorers began traversing the globe. While the compass has not changed dramatically, many other tools have been invented. We loved reading about the tools early explorers used to navigate in North Star Geography and have enjoyed using some of these ourselves.

Compass: a good orienteering compass is important for learning and using a compass. Compass Sighting, or triangulation, uses two points to determine your location using a compass, a map, and a pencil. We use a compass often – we love the sport of orienteering.

Marine Astrolabe: The original tool for mariners, the astrolabe was a circle, held by a ring at the top, with a movable sight. The navigator would hold the instrument by the ring to determine the angle of a star relative to the horizon. The navigator would often sight multiple stars and consult reference books or Star Charts for accuracy.

Quadrant: Similar to a Marine Astrolabe but only a quarter of a circle and with a longer sight, allowing for greater accuracy.

Sextant and Octant (1700s): Instruments similar to a Quadrant but smaller (1/6 and 1/8 of a circle) that relied on two sights – one for the horizon and another for the sun or stars. Mirrors were used so that someone could see both objects at the same time.

Radar: A modern device that uses radio waves bounced off distant objects and calculates the time it takes them to return to calculate distance.

Sonar: Another modern device that works the same way underwater, but using sound waves instead of radio. We have utilized sonar on a few occasions – while fishing with family on the North Sea, while enjoying water sports on Shasta Lake, and most recently in the Galápagos. It is fun to see what the surface looks like below the water.

Topographic Maps: In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, using contour lines to show elevations and landforms. We love looking at topographic maps and have even used them to create 3-dimensional models, Build Geography Skills with Topographic Maps.

Other tools used by navigators include a Chip Log (piece of wood tied to a rope with knots at regular intervals), GPS, and Binoculars.

Bring it Home

Map the sky: Learn to recognize constellations through the seasons and how navigators used the stars to stay on course.

Use a sextant to sight the north star to measure your latitude. You can determine this using the maximum height of the sun during the day and the maximum height of the north star at night. It is easiest to do this on a beach (large lake or ocean) where you can site off the water, but you can do it in your backyard using a level as well. The trick is finding a sextant! See How a Sextant Works for more information.

Navigation where you are: How was your state or area explored? Here in California, Sir Francis Drake is linked to the earliest exploration here, though some historians dispute he ever landed here. Who is a famous explorer where you live? Study more about him. Where was he from? Who traveled with him? What navigational tools did he have at the time?

Determine Magnetic Declination: This is the difference between magnetic north (or south) on your compass and true north (south). This will vary depending on where you are and over time. You can usually find the magnetic declination on USGS maps for wilderness or navigational use. We have one of some local forest lands which include the magnetic declination as part of the map’s key. If you can’t find out specifically what it is where you are, just investigate what it means and how to find out what it is and why it’s important.

The new school year is well under way. In many science classrooms around the world, students are engaging in hands-on science experiences. Many are beginning to give thought to the annual science fair project that often takes place in the spring.

Inquiry based science fair projects are the keystone of student science fairs. They follow the scientific method rather closely and have several parts including a control and a variable.

Inquiry based science projects allow students the opportunity to become the scientist themselves, using their own observations and experiences to ask questions and form hypotheses. Ultimately students design an experiment to test their hypothesis against variables.

Independent Variable: What the scientist will be changing during the experiment
Dependent Variable: What the scientist will be measuring or observing.
Controlled Variable: What the scientist keeps the same during the experiment.

100sciencefair Many educators believe all hands-on science is inquiry science, but that is not accurate. Inquiry implies that students are in control of an important part of their own learning where they can manipulate ideas to increase understanding. As students learn to think through the designs and developments of their own inquiry, they also develop a sense of self-responsibility that transcends all subject areas.

At the elementary level, science depends on the ability to identify and accumulate facts (grammar stage), organize and analyze those facts (logic stage), interpret and theorize about the facts, and communicate those interpretations and theories to others as they move investigations into their communities and participate in solutions to science and technology issues (rhetoric stage).

The 5 features of science inquiry

Student Engages in Scientifically Oriented Questions
Student Gives Priority to Evidence in Responding to Questions
Student Formulates Explanations from Evidence
Student Connects Explanations to Scientific Knowledge
Student Communicates and Justifies Explanations

Although each component is important, helping students use evidence to create explanations for natural phenomena is central to science inquiry. You can reinforce the creation and critiquing of arguments in your classroom by asking, “How do you know?” Student answers (both verbal and written) should include evidence. Additionally, you should look for opportunities for students to critique the use of evidence in science news, reports and other media.

Students should practice science in the classroom the way that scientists and engineers do. Provide opportunities to work in collaborative groups to solve problems and explore challenges. Science and engineering practices should not be isolated inquiry activities, but  permeate the entire curriculum.

Below are 100 ideas for incorporating inquiry science into you curriculum and to kick-start the planning for your science fair project.

100 Science Fair Projects

Life Science

Study the conditions under which mold grows best.
Figure out what is the best preservative to prevent mold growth.
Do plants really respond to music? Affection? Sound?
What type of fertilizer or “plant food” works best?
Sugar level in plant sap at different times and dates
Effect of salinity on brine shrimp or other organism
Can paper chromatography be used to identify different species of plants?
Study the effects of phosphates on aquatic plants.
Compare organic fertilizer versus chemical fertilizer.
Test the effects of heat, light, carbon dioxide, pH level, etc. on the germination rate of monocots compared to dicots.
What factors affect the rate of photosynthesis (temperature, light intensity, water, carbon dioxide, part of the light spectrum, etc.)?
Do the numbers and sizes of leaf stomate vary with different plants?
Study the effect of light or temperature on Vitamin C content of orange juice.
What are the effects of water temperature on the color of fish?
Do the non-smoking sections in a restaurant protect you from second-hand smoke?
Does caffeine have an effect on blood pressure?
Are herbs (or essential oils) a viable alternative to modern medicines?
Which is better – commercial antacids or herbal remedies?
Does playing video games affect heart rate?
What time of bread grows mold the fastest? Compare the buns of various fast-food restaurants.
Are some types of makeup more prone to bacterial growth?
Compare the rate of mold growth on different milk samples (Vitamin D fortified, 2%, 1%, RAW, etc).
Study of insect of animal behaviour versus population density.
Study insects’ adaptations to pesticides or availability of food. Does their body structure change over time?
What is the effect of caffeine or tobacco on the growth of mealworms?

getting started cover

I have written a guidebook to inquiry science with middle school students. It is available in my store.

Earth Science

Does the height of a volcano affect the viscosity of the lava?
Grow a crystal garden. What factors affect the rate and size of crystal growth?
Is there a relationship between sunspot cycles and earthquakes?
Study the small scale wind currents around buildings.
What effects the rate of evaporation the most – temperature, humidity, wind speed, or other factors?
Make observations of geomorphic factors in your local area.
Do the phases of the moon affect the barometric pressure?
Make an instrument to test the soil and find out how compacted it is.
Study the effects of solar activity on radio reception.
What factors affect the slope stability of sand/gravel hillsides?
What substance is best to use in blocking floodwaters?
Study the impact of feed lots on the environment.
How does particle size affect the porosity of soil?
Explore methods of controlling erosion.
Compare the erosion rates of different soil types.
How does the weather affect the salinity of natural aquifers (lakes, rivers, bays, etc.)?
Some intertidal animals in the low tide zone and others in high tide zones. How much time does each zone spend out of water during a tidal cycle?
When are tidal height differences the greatest?
Study the effect of water depth on wave velocity.
Does the moisture content of soil affect the color?
Can mapping earthquakes help identify fault lines?
Build a simple model system to simulate underground water flow, simulate various underground conditions, and test your predictions on water flow.
Which materials make the best compost?
How does soil affect the pH of water?
Investigate how the volume of wet sand changes under pressure.

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Physical Science

Explain how trajectory affects flight distance and vice versa in paper airplanes.
Explain how putting a spin on a ball affects the flight pattern. (How does a curve ball work?)
Which anti-bacterial hand lotion is most effective? (Grow your own bacteria in a petri dish.)
Which brand of popcorn is best? (As judged by which brand leaves the least amount of kernels unpopped.)
Which stain remover works best?
Analyze soil samples for their components, ability to hold moisture, fertility, and pH.
Test the mineral concentrations in hard and soft water.
Compare the results of a common gak or silly putty recipe using different types of glue.
What types of paper decompose the most rapidly when buried?
Compare the surface tension of various liquids.
Study the radiation patterns from different antenna types.
Do bends in fiber optic cable cause loss of audio data transmission?
How does the curvature or materials of different lenses affect a light beam?
Does water droplet size affect rainbow brilliance?
How will the height from which an object falls affect the distance another object moves when struck?
How is the density of a substance/object changed as its temperature changes?
Measure your reaction time and compare it to your friends and family with this fun experiment.
How does the position of a violin or guitar affect the volume?
Do different businesses play different tempos in background music?
Do different businesses use different air fresheners or scents to influence their customers?
Determine how high a basketball bounces on different surfaces relative to the height from which it was dropped.
Find out how the simple aperture design of a pinhole camera works to control the way light enters the lens of your camera.
What setting of a digital camera takes the better picture of a small object?
How does the shape of a bottle affect the sound when you blow across the top?
Test the absorptivity of different materials (sorbents) to discover which ones are best at removing oil from water.

science fairs

I wrote a five day series earlier this year, The Ins & Outs of Science Fairs, to provide a step-by-step approach to creating a successful science fair project.

Engineering & Design

How do different bridge designs affect the strength of the bridge?
What is the most efficient design for a windmill?
How does the weight and shape of an object affect the rate by which it sinks?
Why do the inside of cars get so hot in the sun? What ways can you reduce this heat?
Design and build an automatic recording weather device. Test it over a period of time.
Create a 3-dimensional, free-standing marble run.
Comparing insulative properties of various natural and commercial insulators. Which are the best?
Which style of roof truss is the strongest?
Demonstrate how an AM radio detector can be constructed out of scrap materials and explain the function of the various components.
How does air pressure, materials, and construction of a ball affect its ability to bounce?
Design a spaghetti noodle and mini-marshmellow tower.
How much force is required to advance a lag bolt (large wood screw with a hex-shaped head) into a piece of wood? How do different types of wood compare?
Is there a correlation between electric motor cooling and efficiency?
What is the most efficient design for a windmill?
Invent a device that can launch a pom pom or marshmallow (the farther the better).
Design and construct a robotic insect.
Create a Bristlebot (made from the head of a toothbrush, a battery, and a small motor) and compare the speed of different toothbrushes.
Test a variety of skateboard wheels on their ability to make a 90 degree turn.
How does ski wax affect the sliding friction of skis? You can model this with an ice cube sliding down a plank: how high do you need to lift the end of the plank before the ice cube starts to slide?
Can you design a toy car that is powered by wind? What is the best design?
Build a water clock.
Can aquatic plants promote pesticide breakdown?
Determine the best gear ratio for your bike, to get the highest speed after a curve and onto a straightaway.
Can rooftop gardens also keep your house cooler and lower your energy bill?
Investigate how changing the angle of an inclined plane affects how the Slinky walks down it. What angle will enable the Slinky to go for the best walk?

For more science resources, check out these wonderful 100 Things posts by my friends at iHomeschool Network:

100 Awesome STEM Resources from Amy at Milk and Cookies Blog
100 Engineering Projects for Kids from Marci at The Homeschool Scientist
100 Infographics for Science, Technology, Engineering, and Math from Amy at Milk and Cookies Blog
100 Learning Resources for Kids Who Want to Be Game Designers and Programmers from Aadel from These Temporary Tents
100 Super-Fun STEM Resources for Kids by Colleen at Raising Lifelong Learners
100+ Ideas for Nature Study from Cindy at Our Journey Westward
100 Things to do Before, During, or After a Nature Walk from Jimmie at Jimmie’s Collage

This post is one of 100 posts compiled by the bloggers of iHomeschool Network, 100 Things. Be sure to visit and enter to win over $370 in cash and prizes.

Gravel, sand, silt, and clay, collectively known as sediment, are produced by the mechanical and chemical breakdown of rocks. Once disaggregated from the original source rock, this material is then eroded and transported by either wind, water, or ice, often ending up at the deposits of rivers or lakes, or ultimately as sediment in the sea.

In STEM Club last week we had learned how to identify rocks and minerals. This week, we took it a step further and discussed how scientists use the characteristics of composition and texture to help hypothesize where a sand sample may have been collected.
sandsaroundworld

Background Information

Composition

The composition of sediment is largely dependent on the source material. For example, the sand around volcanic islands is often composed of volcanic rock fragments, volcanic glass (obsidian), and mineral (such as olivine) associated with volcanic rocks. Sediment found on beaches of southern California are largely composed of quartz and other minerals associated with igneous rocks, which form the bulk of our local mountain ranges.

In areas where there is no good source of sedimentary material from nearby mountains or volcanoes, the sand is often entirely composed of organic material (i.e. shell fragments, coral, etc). These sediments are called carbonates, because they are nearly entirely composed of calcium carbonate (CaCO3).

Texture

The texture of sediment is largely determined by the transportation process. The three important characteristics used to assess the texture of sediment are rounding, size, and sorting.

Rounding

As material is transported, it is subject to abrasion and impact with other particles which tends to “round-off” the sharp edges or corners. A well rounded sand grain has probably traveled a great distance from its original source area, while angular grain has probably only been transported locally. However, large particles tend to round much faster than smaller particles.

Grain Size

The terms gravel, sand, silt, and clay carry with them a size connotation. Gravel is any material greater than 2 millimeters in its largest dimension. This includes boulders, cobbles, pebbles, and granules (in decreasing size order). Sand is any material between 2 mm and 0.06 mm in size.

We usually sub-divide this category into very coarse, coarse, medium, fine, and very fine. In practical terms, very fine sand is about the smallest grain size you still see with your naked eye. Silt is material which is finer than sand, but still feels gritty when rubbed on your teeth. Clay is the finest material of all, and pure clay will feel smooth on your teeth, and will form a sticky ball when wet.

As a general rule, material gets smaller the more it has been transported. Therefore very coarse material usually indicates a short distance of transport and vice versa.
sorting

Sorting

The sorting of a sediment is simply how well the sedimentary material is separated out by size. For example, if all the grains in a sediment sample are very nearly the same size then we say the sample is “well- sorted”. If a sedimentary sample were to contain pieces gravel, as well as sand and silt, it would be a “poorly- sorted” sample.

Sorting is primarily effected by the agent of transport. Water is an excellent medium for sorting of particles by size and density. Wind is probably the best sorting mechanism of all, but of course, only operates on the finer grain sizes (not much gravel is moved by wind transport). Ice is the poorest sorting mechanism, transporting and depositing all sizes of sediment with equal ease.

Sand PowerPoint

Some time ago, I found a wonderful Sands PowerPoint but I have sadly been unable to locate it again. Please – if you are familiar with the original source, I would so much like to point my readers directly to the source and give proper credit.

The following image is a slide excerpted from the presentation. Three sand samples have been photographed under magnification from which the roundness of each sample can easily be identified. The graph below each sample illustrates how well the sedimentary material or sand sample was separated by size.

sands
Sample 1 – This is a medium sized sand with a few sea shell fragments. The sorting of the sand is good. There is not a huge variation in the size of the sand. The graph shows a bell curve with a relatively equal distribution of small, medium, and larger size grains. This is a good example of a BEACH SAND.

Sample 2 – This is a classic example of a DUNE SAND. It is very well sorted and fine grained. Well sorted means that the size of the grains is not varied. Most of the grains of this dune sample are in one size group (96.7% are in the size .009 to .005).

Sample 3 – This is a very poorly sorted sand. There are coarse particles and fine grained particles. This, along with the fact that the sand particles are very angular are the indications that it is a RIVER SAND. In other words, it has not traveled far from its original source.
sandslab

Hands-on Sand Lab Activity

Materials

At least 4 different sand samples collected from different locations; the greater the variety the better
Metric ruler
Microscope
Microscope slides
Sand gauge (optional)
Sediment or sand sieve kit (optional)

Procedure

In their science notebooks, I instructed the students to create a data table with the following 8 column headings:

Sample Name or Number and Location
Color
% Dark Minerals
Grain Size
Rounding
Sorting
Organic Material
Other (probable origin, sketches of grain shape, etc.)

I then encouraged them to examine at least 4 different sand samples from the sand collection provided. To guide their observations, students were asked to fill out the table as they went along. A microscope was also available so they could observe their samples under magnification.

Using the data on their charts and their microscope observations, students should have been able to identify the environment of deposition (beach, dune, or river) of the various sand samples.

It is not easy to tell the difference between rocks & minerals because there are so many kinds of them. It takes years of study to be able to accurately identify a mystery rock.

Last week, we learned of the rock cycle which describes the dynamic changes over time among the three main rock types: sedimentary, metamorphic, and igneous. Today, the kids took part in two rock identification labs to further develop their understanding of the basic rock types.

A mineral is a naturally-occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock is a naturally occurring aggregate or combination of minerals. Rocks do not have a definite chemical composition. All rocks are made of 2 or more minerals, but minerals are not made of rocks.

The Three Main Rock Types

Twelve stations were set up around the room – each with a rock specimen and a card that provided hints as to how that rock was formed. The students rotated amongst the stations and recorded first the name of the rock and then identified which of the tree rock types to which it belonged.

Here are just a few examples of the text clues given on the cards:

Marble :: In the past this was a sedimentary rock called limestone. However, heat and pressure have changed it into a much harder rock called marble. Marble today is used as a building material.

Limestone :: This rock formed when the small skeletons of diatoms, plankton, and other water animals sink to the bottom and are then buried and squeezed to form rock.

Pumice :: This rock came from the foot of a small volcano in central Oregon called a pumice cone. It is so full of holes that it will float in water.

Identifying Rocks – Using a Dichotomous Key

We then utilized a dichotomous rock key to identify a dozen or so small rock and mineral samples. In most cases, we don’t see a rock during its formation, so we rely on rocks’ observable clues to infer their formations. Two clues that indicate a rock’s formation are its composition and texture.

Composition refers to what a rock is made of. The color of a rock can provide a clue to the composition. Fragments of other rocks, fossils, and identifiable mineral grains are also aspects of composition.
Texture is a description of the rock material. It includes characteristics such as crystal size and shape, number of different grain sizes, and alignment of grains.

Together we observed the rock’s texture, conducted a basic hardness test, and identified the minerals that compose it as best we could.

When Using a Rock Key there are a few things you need to know:

When minerals have the time and space to grow into their crystal forms, they grow to beautiful regular shapes that are easy to recognize once you have seen a few examples. In rocks, crystals grow up against each other; they have straight edges and often show flat shiny faces that reflect light like tiny mirrors.

Grains that are not crystals in rock do not have flat shiny faces. They are rounded, like grain of sand, or jagged, like a piece of broken rock. Grain size in rocks can mean the size of crystal grains or of fragments:

Coarse Grained – the rock is mostly made of grains as large as rice, or larger
Medium Grained – the individual grains can be seen without a magnifier, but most of the rock is made of grains smaller than rice
Fine Grained– the individual grains can not be seen without a magnifier

Layers in rocks show in different ways.

In some rocks (gneiss for example) different colored minerals are lined up in ribbons.
In schists, the layers are most often thin layers of mica or chlorite around masses of feldspar or quartz. The top and bottom is almost always mica or chlorite.
In sandstones, different sized sand grains sometimes show as different colors. When the grains are sorted by running water or wind, they show different shades of the same color.
The layers in slate are very thin and straight. The top and bottom layers are usually flat and quite smooth.

Gas bubbles form round or elongated holes in rocks. In pumice, the bubbles may be very tiny. In scoria or vesicular basalt, the bubbles are larger, often as large as peas.

rocktypes

For more information on rock types and identifying rocks, I recommend these resources:

The Rock Identification Key – An online, interactive dichotomous key that walks you through precise steps (no photos)
Identification of Minerals – This website provides clear definitions for common terms or characteristics used to id rocks (cleavage, luster, specific gravity, streak, fracture, etc.)
Rock Identification Tables – A website to help you identify rocks (the tables are clear and provide full color photographs of many rock samples)
Simon & Schuster’s Guide to Rocks & Minerals – An easy to use field guide that contains everything rock and mineral enthusiasts need to know, +1,000 spectacular illustrations
Smithsonian Rocks & Minerals Handbook – Another great field guide that combines 600 vivid photos with descriptions of more than 500 specimens.

Rocks, like mountains, do not last forever. The weather, running water, and ice wear them down. All kinds of rocks become sediment. Sediment is sand, silt, or clay. As the sediment is buried it is compressed and material dissolved in water cements it together to make it into sedimentary rock. If a great amount of pressure is exerted on the sedimentary rock, or it is heated, it may turn into a metamorphic rock. If rocks are buried deep enough, they melt. When the rock material is molten, it is called a magma. If the magma moves upward toward the surface it cools and crystallizes to form igneous rocks. This whole process is called the Rock Cycle.

In STEM Club this week, I shared a game with the students with which we simulated cycling through the rock cycle. I began the lesson with a visual diagram of the rock cycle laid upon the tables and requested the students copy it into their journals. The three major rock types (igneous, metamorphic, and sedimentary) were illustrated, as well as the processes that act upon the rock material.

rockcycle

Magma is molten rock. Igneous rocks form when magma solidifies. If the magma is brought to the surface by a volcanic eruption, it may solidify into an extrusive igneous rock. Magma may also solidify very slowly beneath the surface. The resulting intrusive igneous rock may be exposed later after uplift and erosion remove the overlying rock. The igneous rock, may then undergo weathering and erosion and the debris produced is transported and ultimately deposited (usually on a sea floor) as sediment.

If the unconsolidated sediment becomes lithified (cemented or consolidated into rock), it becomes a sedimentary rock. As the rock is buried the additional layers of sediment and sedimentary rock build and thereby heat and pressure increase. Tectonic forces may also increase the temperature and pressure. If the temperature and pressure become high enough, usually at depths greater than several kilometers below the surface, the original sedimentary rock is no longer in equilibrium and recrystallizes.

The new rock that forms is called a metamorphic rock. If the temperature gets very high the rock melts and becomes magma again, completing the cycle. The cycle can be repeated, as implied by the arrows. However, there is no reason to expect all rocks to go through each step in the cycle. For instance, sedimentary rocks might be uplifted and exposed to weathering, creating new sediment.

Rock Cycle Game

Set up eight stations at which a change in the rock cycle occurs:

Earth’s Interior
Soil
River
Ocean
Clouds
Mountains
Volcano

Each student starts at one area. At each area is a die that the student should role to determine what path they should take. It is possible for the student to remain at the same station for a long time. To alleviate frustration, I thereby stated that after 3 turns the student could go to another station.

While at each station and while moving to the different stations, students must record what is happening. For example,

“I began my adventure at ________ . The first thing that happened was _________, then I went to ___________.”

Students continued to work through the rock cycle for several minutes (until the majority had cycled through 12 steps).

Cartoons

After their journey through the rock cycle is complete, students are encouraged to create a cartoon describing their adventures in the rock cycle. Each cartoon page should be divided so there are 12 boxes (one for each ‘step’ in the rock cycle).

Try it yourself! Download the student handouts and station cards .. Rock Cycle Journey.