Geologic cross sections display the different layers of earth and minerals.
Geologic cross sections are representations of the earth. Imagine cutting into the ground or into a mounting with a laser and then lifting out of the earth a huge square. The square of laser-cut earth would show different layers, depending on how deep the laser cut, that represent different types of earth as well as different minerals and time periods. In grade school, students learn the earth consists of a core, at the center, then the mantle and the crust; the crust is the surface of the earth we walk on or plant seeds. For many children, these images of the core, mantle and crust are the first examples of geologic cross sections they experience. The type of cross section is determined by the purpose for drawing it and the needs of the artist.
Instructions
1. Determine the subject for your geologic cross-section drawing. It may be imagined, simply to demonstrate the layers of the geology, or it may be specific such as from a map or geological study or dig.
2. Draw the basic outline for your geologic cross section. Typically, this could begin at one side of the page near the top and travel across to the other. The line is usually not straight as it should represent the natural surface of the earth. An exception would be if you were drawing a geologic cross section with a paved road on top and perhaps layers of earth, or even a sewer system beneath.
3. Sketch the layers of the cross section very lightly. Without measuring, sketching lightly allows you to easily erase and adjust spacing if one layer seems disproportionate later. On a separate paper it may be helpful to number and label the layers for adding details as you complete the cross-section drawing.
4. Color in the different layers of the cross section, if desired, to represent the differences between the types of minerals or earth found in each layer. For layers that are close together and similar, but not the same, use different shades of the same colors. If you have limited colors, you may also simply use dark and light versions of the same colored pencil to show geological differences in the layers.
5. Label the layers with a pen, if desired, or a dark-colored pencil sharpened to a point. If helpful, you may add dates or date ranges for the layers such as those in cross sections of earth showing the changes for paleontological representations.
Tags: cross section, cross sections, different layers, cross-section drawing, geologic cross, Geologic cross, geologic cross section