Question about sedimentary rocks.?

Question

How do the layers visible in sedimentary rock form and why do they differ?

Answer 1

Like dogzilla says, but add that every time the streams speed up they carry heavier material further and as they slow they drop it earlier so you get layers of finer and coarser stuff. Same things in lakes as the creeks fill them, the water currents sort out the different weights of materials. If you fill a jar with dirty water and shake it then let it settle you will see, the finest stuff settles last and leaves a distinct layer on top of the rest of the mud.

Answer 2

If you've ever gone to a fair or festival of some sort, you've probably seen those booths where you they have the little bottles that you can pour different colored sands. As you put a little of each sand in, it forms a layer in the bottle creating pretty patterns.

That's how sedimentary rock forms. Over the eons, sand and silt on the bottom of a lake will compress down into a layer. As time goes on, there might be different minerals that form in the lake or ocean which form different color layers on the bottom. These layer eventually get pressed together into a stone and you can still see the layers.

Answer 3

sedimentary rocks are formed from great pressure. some pressures are differnt at differnt times thus the difference

Answer 4

Sediments falling out of water....Different colors are due to different types of minerals/sediment.

Answer 5

time and pressure of differnt minerals/parts of bigger rocks all mixed and compessed into one stone.