Often when you are near a lake or other body of water you will notice rocks along the shore. This is due to weathering, which is the term used to describe the process of breaking down rocks and minerals into smaller pieces caused from things like water, wind, or ice.
Although there are three types of rocks (igneous, metamorphic, and sedimentary), this lesson will focus on sedimentary rocks which are typically formed in water.
Sedimentary rocks are composed of broken pieces of rocks (also called sediments). They are formed when rock layers are compacted (squeezed together), cemented (bound together by things such as calcite and silica), or recrystallized (new mineral grains formed by interlocking crystals). The rocks at the geozone are all considered sedimentary rocks and have gone through many years of weathering to come to the size and shape they are currently in. I have included a picture example for each formation in the gallery.
The sizes of sedimentary rocks can vary and are defined by the size of the particles that make up the sediment. The smallest sediments are clay which measures 1/256 of a mm, then silt (1/256-1/16mm), then sand (1/16-2mm), granules (2-4mm), pebbles (4-64mm), cobbles (64-256mm), and finally the largest are boulders (256mm).
After answering the following questions, you may log this as a find as long as you do it to the best of your ability. You don't need to wait for my response to claim your smiley, but I will get back to you if there are any issues! To claim credit for this earth cache, please answer the following questions:
1) Looking at the rocks on the shore, what sizes can you identify (please use the proper definitions)?
2) Find an interesting rock and describe the color, texture, size, and shape. Please include a picture!
3) Looking at the gallery for examples, what process do you think helped form the rock in question?