Geologic time relative dating
Speaking of lines, if you see lines or markings that are black, those are typically geologic markings which contrast the brown contour lines showing elevation.The most obvious feature here is color, lots of color.As a member, you'll also get unlimited access to over 55,000 lessons in math, English, science, history, and more.
When you see those lines you know that you are going to be dipping down into a bowl shape. Many parts of a geologic map include things that we have already talked about.Specifically, we will delve into the rules that those lines follow and how to make sense of the numbers associated with them.Later on in the lesson, we'll learn how this information connects to a true geologic map and how to read all those colors. All that means is that where there's a line, everything on that line is the same height or altitude.Each line is a different elevation, but some of these lines have numbers on them. Index contours display the exact elevation of one specific line. Maybe you're at the Pyramids of Giza or one of those big concrete sports arenas or any other place where there's lots of steps. If you start hiking up the stairs, the tenth step up would be painted light brown. If you went up another 10 steps, there would be another step painted brown there as well. While we're focused on lines here, look at the space between any two lines. Contour interval is the distance between any two side-by-side lines.Not just in one spot, the entire step, all the way across. If you keep going, eventually you will probably lose count of how many steps you took. Go run stairs somewhere and try to remember what floor you are on, try a tall hotel stairwell. Why don't you have a seat, catch your breath and take a look around. For example, a contour interval of 10 means you would change elevation 10 feet up or down by crossing over those lines on the map. Every space between every line on that map would be 10 feet of elevation change, no matter how close or spread out those lines are.