Is my basis sound?

Now that I'm done laughing... Percy and Dr A have posted some great pictures that show incontrovertibly that your friend has to be denying reality to state that there are no clear layers in the geological record.However, far more amusing is that it doesn't particularly matter.Let's imagine a world where we didn;t see the clear striations of rock layers in the above photos. Imagine instead that rock blends to rock, that you can't tell one clear layer from another.You can still date a rock through radiological dating. It seems pretty easy to argue that a fossil must correspond roughly to the age of the rock that contains it - else, how did it get there?The fossil ages shown by the ages of the rocks that contain them, whether from a clear layer or not, still show us a clear gradation of species as new features evolve. Look back far enough and you'll see not a single fossil that contains a vertebrate animal, and none appear in earlier fossils either, ever. Look at a different time and vertebrates appear to have been thriving, yet you'll see not a single mammal, and neither will you find one dated earlier.The deposition of fossils over time shows us with nigh-certainty that there is a temporal progression of biological clades, that specific defining features develop and then diversify as you look forward through time, and that it works this way consistently around the globe and no matter which time period you investigate. First there are no vertebrates, then one or a few vertebrates appear, and then vertebrates diversify, and then the diversified vertebrates diversify further.If your friend accepts radiological dating of rocks, then he must also accept that radiological dating may be done for fossils left in those same rocks. The rest is very simple logical extrapolation, and the evidence verifies the resulting prediction every single time.The pictures should be more effective at proving that he's clearly got more than a few things significantly mixed up in his internal model of reality, though.