Last week we went on our 6th grade overnight field trip to Pinnacles. A highlight of our trip was rock climbing up the 100 million year old rock formations. Another highlight was learning about the fascinating rock history, and how they came to be. The Naturalists taught us how to put our trust into other peoples hands while they balay us up the looming rocks.
Many thousands of years ago there was a super volcano. This volcano had a gigantic eruption; it was so big you can find lava rocks miles away! This volcano was along a fault line; a fault line is a border between two plates, in this case it has the Pacific plate to its west, and the North American plate to its East. This fault started to move, it split the volcano into two. These two sections are about 100 miles apart, and one of them is now Pinnacles National Monument.
There are three major types of rock in Pinnacles: tuft, banded rhyolite, and massive rhyolite. Massive rhyolite has different rocks mixed in. This rock is grey or red and, as our naturalist described, it looked like a chocolate chip cookie. The reason for this is that as the lava was flowing down the mountain it picked up more rocks, and when it cooled those rocks became part of the rock. Banded rhyolite is formed by flowing lava when it cools; it has swirls and lines in it. Tuft is formed by compressed volcanic ash and is very light, because its density is low. Tuft has a slight green tint.
The day before climbing up the sheer cliffs we went to “ground school.” At ground school our class learned how to balay and backup balay each other. We also learned the acronym C.R.A.S.H (carabiner, rope/knot, attitude, shoes and stuff, and Helmets harness and high five). The next day we woke up early to reach the climbing spot. Once we got there we strapped on our harnesses and helmets and looked up at our climbing spot called Tourist Trap. It is called Tourist Trap because it is right by a trail were tourists cock their heads at the climbers. Once we were about to climb we recalled C.R.A.S.H and found our first foothold. It only took us a fraction of a second to realize that the rhyolite rock would make perfect foot and hand holds. There were cracks running up the wall that could help you climb to. At first I was a little scared knowing that my classmates were balaying us but after awhile you learned to trust your classmates.
Before we knew it we were taking off our helmets and harnesses and making our descent back down the hill, watching the ancient cliffs get smaller as we walked back to camp. Some of us a little scraped up, some of us exhausted, but all of us with smiles on our faces. Our class wondering if we would ever climb at Pinnacles again.
Categories: Field Trips