Answer:
To read the rocks the geologists need to be aware of several things and rules.
They must keep in mind that older rocks are always in the bottom area. The younger rocks keep on getting deposited on the upper layer of the older rocks.
The other rule is that the sedimentary rocks are usually deposited in the horizontal layer directions.
The spreading out of the sedimentary rocks are in all directions possible unless it gets thin out or until it runs into a barrier.