Question

The diagrams below represent rock layers found in two different locations by two different scientists. The scientist at location X used letters to label his rock layers, while the scientist at location Y used roman numerals to label her layers. Examine these diagrams and then answer the question that follows.



The scientists both used the same colors and patterns to represent different types of rocks. They also used the same set of black-and-white symbols to represent specific types of fossils in the layers. By correlating layers based on fossils and rock types, the two scientists have discovered that certain rock layers are present in both locations.

Which layers are the same?
A.
Layers P, Q, R, and S are the same as layers I, II, III, and IV.
B.
Layers T and U are the same as layers VI and VII.
C.
Layers P, Q, R, and S are the same as layers IV, V, VI, and VII.
D.
Layers T and U are the same as layers I and II.

Answer 1

I can’t see the diagrams you’re referring to. Could you either upload the images or type a brief description of each layer (for example, from top to bottom list each layer’s letter/number, its rock pattern/color, and which fossil symbol(s) are present)?

If you want to try on your own, here’s the fastest way to decide which answer choice is correct:

1. For each layer at X (P, Q, R, S, T, U) note: rock type/pattern and the fossil symbol(s).
2. Do the same for each layer at Y (I–VII).
3. Find exact matches of both rock type and fossil symbol(s). Those matches are the correlated (same) layers. If several adjacent layers at X match several adjacent layers at Y in the same order, that identifies a block of layers that are the same.
4. Compare your matches to the four answer choices:
- A says P–S match I–IV (top four).
- B says T–U match VI–VII (two bottom tiers).
- C says P–S match IV–VII (the lower four at Y).
- D says T–U match I–II (top two at Y).

If you post the diagram or the layer descriptions, I’ll map them and give the correct choice.