Question

sand was deposited in a desert. over time, the climate of the area became wetter. a river began flowing through it. layers of silt were deposited by the river.
thousands of years later, the environment became dry again. the river dried up, and layers of sand were deposited on top of the older sediment.
which rock sequence is more likely to form from the sediment layers described above?
younger
↑
sandstone
siltstone
sandstone
older
younger
siltstone
sandstone
siltstone
older

Explanation:

Step1: Identify sediment deposition order

Oldest: desert sand → Middle: river silt → Youngest: dry sand again.

Step2: Match to rock types

Sand forms sandstone; silt forms siltstone. So sequence (oldest to youngest): sandstone → siltstone → sandstone.

Step3: Compare with graphs

Top graph: youngest (top) sandstone, middle siltstone, oldest (bottom) sandstone. This matches.

Answer:

The Top Graph (sequence: youngest sandstone → siltstone → oldest sandstone)