* Layer Above: The layer above the 120-million-year-old layer must be younger than 120 million years old. This is because in undisturbed rock layers, the oldest layers are at the bottom, and the youngest layers are at the top.
* Layer Below: The layer below the 120-million-year-old layer must be older than 120 million years old. Again, this follows the principle of superposition in geology, where older rocks are found beneath younger rocks.
Important Note: We can't determine the exact ages of the layers above and below without further investigation. They could be slightly younger or older than 120 million years, but they definitely fall within those ranges.
