WOW!!! So all the mountains ranges in the world and deep gorges in the Oceans are less than 6K years old? That assumes some time between Adam&Eve at 6K years and Noah.
I grew up in private Christian schools that taught young earth and the reasoning they gave was that when the water came up from the earth to flood, it created the mountains. Of course, there is no explaining how the Earth held that much water in the first place and where are these vast, empty chambers that billions of cube miles of water would have been in... the earth would have had to be hollow.