Ok, so... you know that these are sedimentary rocks, because they're bedded, right?

Now, the first sample you saw was well-sorted with sand-sized grains.

• If you identified this rock as a sandstone, nice job!!

What about the second sample. It was well sorted, and very fine grained.

• Siltstone?? Right again!!

Great! So you've identified the two rocks that make up the lower rock unit.