How can there be traces where there is physically empty space?
You did not specify where these youngest rocks are found. Are you saying that the Grand Canyon has been in it’s current form for 270 my? When I hear youngest, it is the most recent event. My youngest brother was born last and closest to current time. If you mean the youngest as being young 270mya, it is pointless. All things are young at the beginning of their existence. If you mean oldest, then forget me trying to figure out what you mean. Otherwise you are saying in this empty space we call the Grand Canyon we can without observation, see exactly how things happened over time where empty space now is.
Ie. It just happened because it can. The date of some rocks date to 270mya. Not all of them? Technically only the ones found near the top would indicate the age when the river was there before a Canyon formed. Not to be mean. But if we dug down thousands of ft. Into the earth, and uncovered a rock dating 270mya then we can assume 270mya worth of history as been laid down on top of this one rock, or it took 270mya for this rock to travel that distance.
When it comes to the Grand Canyon you seem to be saying that the Grand Canyon took 270my to form the walls and then perhaps half that to carve out how it currently looks. Because if the river itself was under a lake and there was no Canyon, as we see it today, are you saying that the ground actually moved up while the river moved down? If a 270mya rock is found at the bottom near the current river, it could have come from anywhere. Saying that it took 270mya for the river to find this 270mya rock does not make sense. It is like trying to dig down yourself to a certain level in the earth and find the same 270mya rock. The point of dating is to not point out certain rocks. It is to date as many items as possible in as many areas as possible and then give as best of a picture as to be had taking into consideration all the natural things that could happen. My point was if things did not happen as predicted, and there was a phenomenon that changed anything at any time, that picture is just fake, even if it looks real.
I get the point there were seas in the area. However the rock could also have been there 270mya before the seas themselves.