Thursday, December 17, 2009
High School Freshman visits the Podcast
Sunday, December 13, 2009
Weathering and Erosion Posters
Wednesday, December 9, 2009
Case Study: The Black Hills
Many of you have been out to the Black Hills. If you haven't (or if you can't remember what it is like), visualize the following scenario:
As you drive west from Rapid City, you notice a jagged stretch of sandstone peaks called the Hogback Ridge. After a short descent from those sandtone peaks, you come to an area comprised of another sedimentary rock, red shale, which makes a "Racetrack" around the Black Hills. If you keep driving west, there is a gradual incline made of limestone. This limestone formed 100-500 million years ago, from the shells of ancient marine animals. (Yes, we are still in the Black Hills of South Dakota.) Keep driving still, past this limestone plateau, and you will see the Central Crystalline Core of the Black Hills. This area is made of schist (a metamorphic rock) and granite (an intrusive igneous rock) that have aged for up to 2.5 billion years. The apparent color of this Central Core and the groves of Ponderosa Pine gave this area its name, the Black Hills. You might want to get out of the car and take a hike up to Harney Peak, the highest peak in between the Rocky Mountains and the Alps of Switzerland.
What are the events that led to the formation of these Black Hills? Why does it look the way it does? Like geologists, we will explore these questions today.
If you were not in class for the presentation (or if you could use it to review), here is a video:
Here is a link to the presentation (without sound): Formation of the Black Hills
- Write a summary of how the Black Hills formed. What are the events that led to their formation?
- Would the Badlands exist if weathering/erosion had not taken place? Why/Why not?
- The major uplift of the Black Hills occurred 70 million years ago. What do you think that area of South Dakota looked like 40 million years ago? What do you think the Black Hills and Badlands will look like in another 40 million years?
Tuesday, December 8, 2009
Tape a Student Day
Tuesday, December 1, 2009
Rocks
In science, it is our duty to ask "Why?" and "How?" questions about things that are around us (whether those things are common or extraordinary). Like rocks. I have a couple of those questions for you, Crazy 8s:A: This is a picture of an igneous rock. You may construct a paragraph that answers the following questions, or you may answer each question individually.
- Why does this igneous rock have crystals?
- Where did this rock form? How do you know?
- What type of igneous rock is this?
B: This is a picture taken in the Badlands of South Dakota (there are other "badlands", too). The rocks that you see are sedimentary rocks, and they have NOT always been there. Use your knowledge of the rock cycle to answer this question: (If you need a refresher, view the rock cycle prezi in the blog post below this one.)
- How did these sedimentary rocks get here? (What are some of the events that could lead to the formation of sedimentary rocks?)