The Age of Rocks - 9/10/17

https://upload.wikimedia.org/wikipedia/commons/thumb/a/a0/Cross-section_of_sedimentary_layers.png/500px-Cross-section_of_sedimentary_layers.png

The Geological Time Scale is a record of the life forms and geologic events in Earth's history. The Geological Time Scale includes the age of rocks or the years since the rocks are formed. There are two ways that geologists determine the age of rocks. The Relative age is the age of a rock compared to the ages of other rocks. For example the rock is younger than the rock beneath it. The Absolute age is the number of years since a rock is formed. For example the rock is one million years old. The law of superposition states that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it. Therefore the older the rock is, the deeper it is in the ground. Another way to determine relative age of rocks is the Cross-Cutting Principle: when "something" cuts across a body of rock, that "something" is younger than the rock it cuts across. 

S&EP - SP7: Engaging in argument from evidence

I use evidence to defend my explanation. I took notes on the age of rocks and fossils providing the power point about how scientists find the age of fossils, as evidence. I formulated evidence based on solid data when I stated that the top layer of rock is younger than the bottom layer of rock, using the fact that the older the rock is, the deeper it is in the ground as evidence. I examined my own understanding in light of the evidence. I used to think that rocks were dated depending on what stage of the Rock Cycle they were in, but because of understanding the information on the power point that my teacher presented in class, now I think that rocks are dated by their layers. I collaborated with my peers in searching for the best explanation. I did some research on the age of rocks and fossils which I discussed with my class and table group. Together we figured out that scientists find the age of fossils depending on how deep the rock is in the ground.