Rock Cycle - Rocks (KB)
Pre Lab 

   
OBJECTIVES:
  • Learning that rocks can be created in or near water.
  • Exploring the components of a beach.
VOCABULARY:
  • beach
  • erode
  • ocean
  • river
  • rock
  • sand
  • water
MATERIALS:

Students touch and observe different sands.


beach sand

BACKGROUND:

Sand is a natural component of oceans, rivers, or lakes because the rocks surrounding them have been eroded. Erosion occurs when wind, rain, and ice crash onto a rock and break it into smaller pieces. Within a certain size range, these little pieces of rock are called "sand." If the pieces are bigger than sand, you can call them gravel or pebbles.

Sand takes on the "look" of the rocks that it came. If the rock is granite, the sand will have white, yellow, and a small amount of dark minerals eroded from the granite. If the rock is gabbro, the sand would be very dark. In some cases only minerals will erode from the rock, especially the very resistant quartz and feldspar minerals. In other cases, small rocks will erode instead, because the minerals are too small to erode individually. Basalt is an example, usually forming a dark sand composed of very small pieces of basalt.

Students in the lower primary grades are usually amazed by sand, because it seems so flexible. The feel of sand is also very important to young children. It flows like water,  yet it is not wet. The little pieces are colorful. It is no wonder that children like to play in sand boxes.

Sand is the basic building block for sandstone, a type of sedimentary rock. Sandstone forms when individual sand grains are squeezed together by pressure and cemented. Sand can thus be thought of as "baby rock."

PROCEDURE:

  1. Ask students where water can be found. Many students will respond with answers such as "fish tanks and bath tubs," but try to direct their comments toward rivers, ponds, lakes and beaches. Where your children live will obviously influence their responses.
     
  2. If any of your students have been to a beach or lake, have them describe to the rest of the class if they played in the sand or the water. You may also tell them that when you were a child, you played in the sand. Describe how the sand felt to you as a child. Ask the students what sand is composed of. Sand can be called "baby rocks." If the "baby rocks" were cemented together, they would form sedimentary rocks. Sedimentary rocks are commonly formed in or near water.
     
  3. Use the Sand Display kit to show students all the different sands that have been collected from various beaches of California. You might supplement this exercise with samples of sand that you may have collected.
     
  4. If you have a sand box you may want the students to explore the sand in the box with a hand lens.
     
  5. Have the students color the worksheet. This exercise will guide them to think about the "baby rocks" that are formed along the beach. Ask the students to bring in baby food jars or jelly jars to class to be used for the lab.

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