Geologic time scale and relative dating lab Bi sex phone chat
Topics include rock layer sequencing, fossil correlation, and radiometric dating.A few days ago, I wrote a post about the basins of the Moon -- a result of a trip down a rabbit hole of book research.When you find the same fossils in rocks far away, you know that the sediments those rocks must have been laid down at the same time.The more fossils you find at a location, the more you can fine-tune the relative age of this layer versus that layer.On Earth, we have a very powerful method of relative age dating: fossil assemblages.Paleontologists have examined layered sequences of fossil-bearing rocks all over the world, and noted where in those sequences certain fossils appear and disappear.
With this kind of uncertainty, Felix Gradstein, editor of the For clarity and precision in international communication, the rock record of Earth's history is subdivided into a "chronostratigraphic" scale of standardized global stratigraphic units, such as "Devonian", "Miocene", " ammonite zone", or "polarity Chron C25r".
Here's the next step in that journey: the Geologic Time Scales of Earth and the Moon.
In the science of geology, there are two main ways we use to describe how old a thing is or how long ago an event took place. When you say that I am 38 years old or that the dinosaurs died out 65 million years ago, or that the solar system formed 4.6 billion years ago, those are absolute ages.
Something else must serve to establish a relative time sequence. Earth is an unusual planet in that it doesn't have very many impact craters -- they've mostly been obliterated by active geology.
Venus, Io, Europa, Titan, and Triton have a similar problem.