E203: What can rocks tell us about the past? [SJK Audio Edition]

Read this article at: or watch at: https://youtu.be/u64V_AHfE_sSummary: Researchers used two methods to determine the pressure experienced by rocks in the Grand Canyon to make a more detailed timeline for the area. Abstract: Did you know the Grand Canyon can help us figure out what happened on Earth long ago? As in, 1.7 billion years ago? As we go down into the Grand Canyon, we find older and older rocks. Some of the oldest rocks are in a section of the canyon called the Upper Granite Gorge. These blocks of metamorphic rock formed when older rocks experienced extreme heat and pressure. We wanted to figure out the pressure experienced by four of the blocks. We collected five samples and analyzed them. We used the minerals in the rocks to determine the pressure each block experienced. We learned that the blocks formed under different pressures. We also found out that the blocks that formed at higher temperatures experienced higher pressure than blocks that formed at lower temperatures. The difference in pressure made us realize the blocks formed at different depths. Then they moved when tectonic plates pushed together to form mountains.You are one of half a million educators in the U.S. who use our articles and videos in class. All our content is FREE, no paywalls, no need to subscribe. But recent federal cuts have made it hard for us to win grants to fund our mission. We are a small non-profit, and without support, we may not make it.If you enjoy our content, please consider donating - https://www.sciencejournalforkids.org/support-us.html This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit sciencejournalforkids.substack.com