See the Past

This is intended for beginning geology students and others who would like a visible example of geologic reasoning. Starting with a very simple geologic structure, we step backwards in time to see how things may have looked in the past.

The first page presents a completely familiar scene that everyone should be able to easily grasp. What's different about this is that we allow or maybe even encourage the wrong answers, so everyone can clearly see why they're wrong. This can provide powerful visual reinforcement for geologic concepts like superposition and fault movements.

Multiple Learning Modes

This is designed to be used in several educational settings:

• Classroom or Presentation: A teacher or leader can step through a page at a time, for example using an overhead projector combined with verbal commentary.
• Lab or Workshop: Students can be directed to start at the first page, discuss their answers to each question with other team members, and find their way through the sequence. Optionally, they can be encouraged to try the wrong answer too, in order to see why it is wrong.
• Self-Study: The pages can be posted to a web site, where individuals can work at their own pace and level of interest.

Tips for Presenters

• Before beginning your presentation, download these pages and pictures to a local hard disk for fastest response. You don't want to lose momentum while waiting for a slow CD drive or unreliable web connection. (Note that this zip-file can fit on a single diskette, so you can easily take the entire presentation with you. After unzipping, open index.html to see this page, or roadtrk.html to begin the actual tutorial.) Alternately, you could try clicking all the links before your presentation begins, in the hope that your browser will load and cache the images for quicker display later.
• Also before your presentation, set your display resolution so that the pictures fit nicely on your screen. Ideally you don't want to have to do a lot of scrolling around.
• You will be commenting on the pictures and asking your audience the questions. The text is mainly for Lab or Self-Study users. So you can maximize your display space by adjusting the font size in your web browser. As you make the letters smaller, there will be more room left for pictures.
• Ask open-ended or discussion-provoking questions. For example:
  • What do you see?
  • How do you know?
  • What would happen if... ?
• The presentation may be most effective if you deliberately choose the wrong answer to each question. Your audience will vividly see why that answer could not possibly be correct. Then go back to the question (there's a link at the bottom of the page, or use your browser's back button) and choose the right answer. Now it will be more apparent why that answer must be right. If delivered with a good sense of timing and humor, you can build audience rapport while conveying the feeling that geology isn't that hard to understand after all.
• Each page has a small picture of the previous page, to help people see the difference "before" and "after". If anyone still has difficulties, you can use your browser's "back" and "forward" buttons to switch between the pictures several times while pointing out the change.
• When you reach the last page, with the message Can you see even farther into the past? you can click on the small image to move forwards in time again. In other words, now that you have successfully worked your way into the distant past, you can see the evolution of the structure as you move back to the present.
• If you have questions, difficulties, or other presentation ideas, contact the author and I'll see if I can improve this for next time.

How it was Made

I started by taking a couple dozen digital photos of the road cut near Kingman, Arizona. This was necessary in order to get a good shot of a speeding vehicle in the right place without any other traffic in the scene.

Back at home, I used Adobe Photoshop to remove the road from the picture, rewind the fault, and so on. The Google image search engine helped me find the bird, volcano and mountain pictures. I emailed their authors for permission, and blended those pictures into mine with Photoshop. Finally I wrote the web pages using vi, a line-oriented text editor.

Credits

Bird pictures adapted from http://www.conversion.org/birds.gif, used with permission.

Volcano photo adapted from http://www.heptune.com/pagan1.jpg, used with permission.

Mountain photo adapted from http://www.ucalgary.ca/unicomm/Research/rawson%20lake.jpg, used with permission.

Written by Marvin Simkin Filename index.html Last updated September 26, 2002

Permission is granted to freely copy and use this material. However, I encourage you to contact me by email first, in case improvements or corrections are available.