Question

Where there are layer of sediment laid down over many years. Which layer is the oldest and why ?

Answer 1

Answer:

the bottom most layer I.e layer 1 in is the oldest rock layer

Answer 2

Answer:

The bottom most layer. This is because the layer is in the very bottom which states that the sediment at the bottom was deposited before the sediment in the other layers. This would be because the sediment in the bottom layer is heavier in mass.