 So far Braden have told you a lot of theory about how to decode the history that's recorded in rocks and today we're going to put all of that into practice to try and figure out what was going on at our nation's capital Hundreds of millions of years ago. Here we are at the state circle road cuttings You can see that we've got two distinct rock units that you can see here separated by this weird wiggly line down here we have a Silty layer where the grain size is much finer than the stuff up here Which is more sandy and these two rock units are separated by this wiggly line that you can see Before I continue any further I'd like you to stop this video and have a think about what might be going on here Try and create a relative timescale of your own