Question

read the passage and answer the following question(s).
dating rock strata
scientists can determine the age of rock layers by measuring radioactive elements within the rock.
radioactive elements found in sedimentary rocks decay quickly, so this method can only date
sedimentary rocks that are less than 50,000 years old.
volcanic rock contains radioactive elements that decay
very slowly, so scientists can date volcanic rocks that
are much older than 50,000 years.
a team of scientists is investigating a rock formation
found in a region. the diagram shows the rock
formation that the scientists are investigating.
use the drop - down menus to complete the sentences.
scientists can determine the absolute dates of rock above and below the volcanic layers by using the law of superposition. this law states that younger rock forms on top of older rock.

Explanation:

The law of superposition is a fundamental principle in geology. It states that in undisturbed sedimentary rock layers, the younger rocks are formed on top of older rocks. This is because each new layer of sediment is deposited on top of the existing layers. So, when scientists look at rock layers (like the ones in the diagram), they can use this law to determine the relative ages of the rocks. For example, if there is a volcanic layer, the rocks above it would be younger (formed on top of it) and the rocks below it would be older (underneath it). The absolute dates of rocks (which give the actual age in years, like 240 million years old or 460 million years old) can be determined using radiometric dating (as mentioned in the passage about radioactive elements in volcanic rocks). But for the relative positioning (which rock is older or younger in terms of layering), the law of superposition is key.

Answer:

Scientists can determine the absolute dates of rock above and below the volcanic layers by using the law of superposition. This law states that younger rock forms on top of older rock.