The correct order is as follows:
- Shallowest
- Second youngest sediment layer
- Highest carbon-14 to carbon-12 ratio
- Second oldest sediment layer
- Deepest
What is the principle behind this?
This is based on the principle of stratigraphic superposition, which states that in an undisturbed sequence of sedimentary rocks, the layers are the oldest at the bottom and the youngest at the top. The carbon-14 to carbon-12 ratio is also a good indicator of age, with older layers having a lower ratio and younger layers having a higher ratio.
Therefore the order is:
Shallowest
Second youngest sediment layer
Highest carbon-14 to carbon-12 ratio
Second oldest sediment layer
Deepest