Concretions: An Interesting Stop on the Rock Cycle

Three friends and I recently took at kayak trip through the White Cliffs of the Missouri River in north-central Montana. We took time to do some short hikes to explore the fascinating geology of the area. During one excursion we hiked into the Eagle Creek drainage where concretions are especially abundant. Telling students about "concretions" is a great way to make the "compaction and cementation" (lithification) part of the rock cycle more interesting. Before you explain how they are formed, consider showing students photos of concretions* and then ask them to come up with a theory. To learn more about concretions CLICK HERE. Similar processes were also involved in the formation of the strange pedestal rocks, which we saw several miles downriver. To see 45 photos from our trip, CLICK HERE.

NOTE: If students have a good understanding of "plate tectonics" and "the rock cycle", they have a decent foundation in geology. For more about the rock cycle, check out this Rock Cycle PenCast.

*The links embedded in the above text will take you to several photos.

Quality Online Courses for Earth Science Teachers

Some of the best courses that I've taken over the years have been those provided by the American Meteorological Society. The AMS offers online courses related to meteorology, oceans, water systems, and climate. They are free, and you earn 3 graduate level semester credits! More importantly, the courses are top-notch, but not overwhelming. I've taken all of them except for the climate course, and they have all impacted my instruction in a positive way. I highly recommend them. CLICK HERE to learn more about the meteorology course or HERE to learn more about the other courses.

This week on PBS: The Dust Bowl by Ken Burns airs on PBS Sunday and Monday evening, Nov. 18-19 at 8 pm Eastern Time. Also, the topic of this week's NOVA is about superstorm Sandy.

The Role of the Moon on D-Day

In honor of Veterans Day (Nov. 11) take a look at how the Moon played a major role in the planning of one of the most important invasions ever; the invasion of the northern coast of France on June 6, 1944. CLICK HERE to find out more.

Image Lets You See Vapor in the Air

One of the best things about the internet is the access that it gives to real-time weather images. This allows me to show students many different aspects of a storm as it moves through. As much as I enjoy geology topics, it seems that students have a hard time getting excited about changes that take place over thousands or millions of years. On the other hand, weather changes from hour to hour, minute to minute. We can compare what we see happening outside to satellite images, weather maps, RADAR images, pressure maps, temperature maps, current wind animations, etc. Its relevant and it makes sense!

One of the fun new images I learned about on Mike Heard's Blog shows "Total Precipitable Water" (vapor in the air over ocean water). Mike is a broadcast meteorologist in Butte, Montana. He explains the images on his blog site. To see the current loop, CLICK HERE. . . Or, CLICK HERE to watch a YouTube video about the images.

Phases of Venus Animation

One of the most difficult things for students to comprehend is why we see what we see in the night sky. Animations such as this one can help by giving students a different perspective. The animation shows what Venus looks like from our point of view as both Earth and Venus orbit the Sun, and it can be paused for discussion. Ask students if they can figure out why Venus is always either a "morning star" or an "evening star", but cannot be seen at mid-night. CLICK HERE to check it out.

UV Beads Are Great for Experiment Projects!

I tried something different during my unit on ozone depletion. . . . and it worked real well! I ordered a bunch of UV-sensitive beads from a company called Educational Innovations. The beads change from white to colored when exposed to the Sun's ultraviolet rays. They come in packages of 240 for $6.95.

Here's what I did. I gave each student a zip-lock snack bag with 12 beads (4 that turn yellow, 4 that turn red, and 4 that turn blue). Next, I explained that each of them would need to design, and carry out an experiment to find the answer to one of the questions listed HERE (or one of their own questions). The students were given 1 week to complete the project.

The sky is falling!

On a recent hike, I took some time to explore a blow-down near the Continental Divide in western Montana. The reason for the blow-down involves some pretty cool science (related to density and phase changes). CLICK HERE to see lots of photos and read the explanation.