 Hey Shrida, look here, the chain that we're using to climb up the hillside here in Zion is actually causing some mechanical weathering and you can see how everybody that grabs onto the chain as it goes up, it carves into here. Cool, check it out. Yeah, so it's made these little scallop marks where the chains that are turned in this way have gone a little bit deeper and the chains that are out that way are back a little bit farther. Yeah, it would be like a rock in a stream or even a glacier pushing stuff along, it's just scooping things out, constant pressure along the side of the rock. And so this stuff is actually fairly friable, it breaks apart reasonably easily, this chain has probably only been here 10, 15 years and already it's cut in a quarter of an inch, an eighth of an inch, something like that.