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Tallgrass Prairie Center

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Rock to Rock

Adapted from Keepers of the Earth

* Educators please refer to New to Nature for information on becoming comfortable teaching through the outdoors

Overall Activity

Students will listen to a rock story as they imagine they are becoming different kinds of rock over time. Identify & discuss the three major types of rock and the cycle through diagrams or pictures. Refer to Procedure for story, discussion points, and other details.

Grade Range and Relevant Iowa Standards: 4th - 7th

  • 4-ESS1-1. Identify evidence from patterns in rock formations and fossils in rock layers to support an explanation for changes in a landscape over time.
  • 5-LS2-1. Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.
  • MS-ESS2-3 (6th) Analyze and interpret data on the distribution of fossils and rocks, continental shapes, and seafloor structures to provide evidence of the past plate motions.
  • MS-ESS1-4 (7th) Construct a scientific explanation based on evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history.

Goals/Objectives:

  • Review or identify the key differences between the three main types of rock
  • Understand & identify the various aspects of the rock cycle
  • Discuss the weathering of rocks and the relationship to soils

Materials:

  • The story ‘Rock to Rock: A Fantasy Journey,’ a rock cycle diagram of your choosing to display during story and discussion (sample below)
  • Optional: Pencils, crayons, colored pencils, & paper; samples of three basic types of rock to be passed around classroom

Procedure:

  1. Read the story copied below as students sit quietly with their eyes closed. 
  2. Stress that the events of the rock cycle occur over thousands and millions of years
  3. After reading the story, discuss the breaking down of rocks into smaller fragments over time form the basis of our soils. Weathered rocks, animal remains, and decaying plants are the makeup of organic matter that build our layers of soils (primary succession). Soils, of course, support our plant growth and make life on Earth possible.
  4. Optional: Have students draw pictures of their rock journey experiences from having listened to the story.

Extensions:

  • Refer to Iowa’s Nature Series for more resources on soils & geology
  • Consider finding map data to analyze, interpret, and describe the patterns of Earth’s features (mountain systems, volcanoes, etc.)
  • Is it possible to find a natural area near school to visit with your classes to record measurements and/or make observations on erosion? Either through water, snow/ice, wind, or vegetation?
  • Start class rock collections by size, shape, or other attributes and compare your classes through various displays or presentations
  • Go outside school to an area with plenty of rocks and have each student find one that is relatively small <1-2 inches. They learn their rock through size, weight, & shape and write their initials on it. Put all rocks into an enclosed bag to see who can find theirs through sense of feeling alone. Do this as a warm up activity to begin class or cool down at end of class
  • Create a slideshow or real-life display of rocks under ultraviolet light

Prairie Connections (some information sourced from Iowa’s Nature Series):

  • Prairies we’re familiar with today in Iowa developed over the last 12,000 years as a result of the current interglacial period (time between glaciers) in which northward migration of plants and animals occurs.
  • The primary soil parent material of Iowa is glacial till which simply means the natural geology of a place and the material forming the soils. Investigate what materials were left behind from glacial advance and retreat. What are they made of and how do they form? Did prairies change these materials and how?
  • Iowa bedrock is sedimentary limestone, shale, and sandstone but large rocks & boulders you may see lining certain fields of Iowa are igneous. How did these rocks get there and are they as out of place as they seem?
  • The weathering, erosion, and deposition involved in the general rock cycle is also influenced by the types of plants and animals in an area. Research what was present at our last glacial retreat and how it changed over time.
  • Relevant graphics follow ‘Rock to Rock’ story from Iowa Nature Series Educational Graphics

 

Rock to Rock Story

 

Imagine that you are a rock as big as a baseball. Your home is on a sunny hillside and you can see down into a deep valley with a river roaring far below. You like your home. Sometimes it is very hot there. Can you feel the sunlight warming you?

    During the winter you get worried about the ice that freezes in the crack on top of you. This crack grows bigger each year because the ice pushes hard on the sides of the crack.

    One spring it is very wet, more wet than you can ever remember. The rain pours in little streams rushing down the hillside. Feel the water flowing over you and into the soft mud below. 

    Suddenly you feel a rumbling and the Earth begins to shake. You look uphill and a large wall of mud rushes down and sweeps you up. You begin to roll down, down, down into the valley. Ow! You hit another rock and you split along the crack. Now you are two halves rolling down the hill.

    Splash! You land in the river. For days and days you are pushed by the swift, strong waters. Rolling and bumping along you are getting all broken up into gravel and sand. Finally the river enters the ocean and your many pieces settle onto a large, flat area along with millions of pieces of sand, gravel and silt.

    Some pieces settle on top of you and you are getting squished. You yell out, “Stop pushing!” but more and more weight presses down. Your pieces get pushed and stuck together with other pieces. You are now hardening and becoming a sedimentary rock. 

    The pressure grows and you begin to get warmer and warmer. You change color and form into many hard crystals. Now you're a metamorphic rock. 

    You keep getting pushed farther down. It is hot. It is boiling hot! Everything begins to melt and you are part of a hot mass of melted rock called magma deep underground. It seems like forever that you are part of this big melted sea of rock. Will you ever see the sun again? You want to be back on your hillside feeling the hot sun and cool wind and rain. 

    Wait, you’re being pushed up and the Earth is shaking and rumbling again. You can feel yourself rushing higher and higher. Fire, ash, dust, and steam surround you and, with a loud explosion, you burst up out of the top of a volcano. Red-hot lava is all around. You are a scalding, steamy piece of lava shooting through the air when, suddenly, you land on a high point of the volcano away from the hot flow of lava below. 

    Slowly the volcano begins to quiet down and the lava cools and hardens. You are now a cold, grey igneous rock on top of a high volcano looking down at a river flowing far below. When the dark ashes blow away and the sky clears, the sun comes out and warms you high up on the volcano -- your new home.


Geologic Cross Section and Stratigraphic Column

Cross-section illustrating key geology terms (bedrock, outcrop, sand, silt, & till)

Iowa Bedrock Ages

Iowa bedrock surface geology map

 

 

 

 

Glacial Regions of Iowa

Basic Rock Cycle Diagram

Rock Cycle Diagram