Apologies in advance for a beginners question. Different rock types make me curious and recently went to an area where interesting sedimentary rock is all over. As the area is on the coast, sea has washed away some soil and is making it easy to observe rocks.
This sedimentary rocks is composed of different pieces. Sometimes the pieces are in different color, while other times are white. I took an image of a typical rock:
How such sedimentary rock is made? In which period of crust formation? Can you point me to links where I can learn more about it?