When most people think of a geological map they think of a topographic map. This is incorrect. A topographic map displays the land as a 3-dimensional space, helping the reading understand what the land looks like as if he were there. A geological map, on the other hand, shows the formation of rocks and faults in relation to streams, rivers and other natural formations. The geological map usually lays over a traditional navigational map, making it easy to know where you are looking. What the map says, however, isn't as easy to understand. Does this Spark an idea?
Instructions
1. Locate the key on the map. This box, usually near a corner of the map, contains all the symbols you encounter on that specific map. A professional geological map also contains an explanation of any rock or sediment units on the map and geological cross sections, which shows the layers of a rock on the map. Read all three of these boxes.
2. Understand the different colors on the map. Each color indicates a certain type of unit. For example, one color might indicate a sandstone rock of a certain age. The key tells you what each of these colors mean.
3. Identify the age of any geological unit per the letters within each colored space. These letters, a mixture of uppercase and lowercase, indicate the period of the rock formation. For example, "J" stands for "Jurassic," which covers the period 195 million to 141 million years ago.
4. Categorize contact lines, faults and folds according to the lines on the map. Each type of line, as indicated in the key, symbolizes each on of these. They help identify parts of the unit. For example, a contact line will show where one geological unit meets another.
Tags: each these, geological unit, unit example
