Sedimentary Rocks are rocks that form over time from layers of sediment. Sediment can be anything from very fine silt and mud, to sand, to pebbles. These sediments can be made by wind or water erosion of other types of rocks, including igneous, metamorphic, or other sedimentary rocks. Over time, the layers compress and harden into rock.
Some sedimentary rocks can be made out of really interesting sediment. Coquina limestone is made from shells!
[Sarah]: All right, so let's talk about some sedimentary rocks, and in this picture we have a little bit of a clue, I think, about how sedimentary rocks are formed, did you want to talk about that?
[Kim]: Yeah, absolutely. So you can see is that a fossil right in the middle there, I would imagine.
[Sarah]: Yeah.
[Kim]: I didn't know Minecraft had fossils, that's really cool.
[Sarah]: It does. This one I built, but you can find them too. We'll get into that in a bit, I think.
[Kim]: Yeah, so I mean, that's an animal that was alive at some point, and got buried with sediments over top of it, and over time it's crystallized into some sort of rock. You can see there's different layers in this in this picture here. So we have some white layers, we have some brown layers, sort of tan layers in between, so I think that's that's very accurate of how sedimentary rocks layer up over time with sediments, for sure. So we can either have silt stones, a really fine grained material, up to sandstone, so that's, like, beach sand that we find just at the beach, and kind of everything in between, even conglomerates or bigger chunks of rock that have been trapped into rocks as well.