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2004 Field Season: Day 21

July 13, 2004

The Geology Field School had their second day of class today, while Amanda tagged along to watch and learn. The students got hands-on training from Kay, who walked them through a part of the Olorgesailie Formation. Yesterday they stayed near the Site Museum, looking at the lowest (oldest) members, while today they looked at Members 3 through 14.

What does a team of geology students see in the Olorgesailie Formation that's different from what archeologists might see? They see the same strata and members as anyone else, but they also learn about the geological process that formed the members and how each one is uniquely recognizable. Even for these already-experienced students, it was sometimes confusing because the members can look very similar, and many geological faults disturb the order of the members across the landscape. Kay has worked here for many years and knows the sediments like the back of her hand, and was able to show the students how to recognize certain features. The students were also tested on their ability to orient themselves on an air photo. You can try a similar exercise in the expedition section of the website.

Kay, with members 3 through 13 visible in front of her.

In the photograph above, Kay is pointing out a thick section across the valley where you can see Members 3 through 11. You can see all of the horizontal lines in the cliff face - these are the different strata in each member. Some of the strata are harder than others, and they form the steeper faces because they don't erode as easily. Some are soft and erode easily, and they form the slopes.

She also pointed out a fault. Can you see it in the photograph below? The red sediment near the top of the image is clearly broken across the fault and is higher on the right and lower on the left.

A geological fault.

Now that they are more familiar with the complexity of the area, the students are ready to start more complicated geological tasks. Tomorrow and in the following days, the students will practice drawing stratigraphic sections, which are maps of the different strata at a certain area. I'll show you some of their work at a later point.

Jenny and Jess returned today. We're happy to have them back in camp, and they showed us photographs and told us stories of their safari to a game reserve in another part of southern Kenya.