Question

in which situation is the principle of cross - cutting relationships useful in determining relative age? a fault breaks through sedimentary layers. fossils of two different species are found in different rock layers. sedimentary layers form over millions of years in a lake bottom. lava flows form on top of one another from several eruptions over time.

Explanation:

The principle of cross - cutting relationships states that a fault or intrusion is younger than the rocks it cuts through. In the case of a fault breaking through sedimentary layers, the sedimentary layers must exist first for the fault to cut through them, so this situation uses the principle of cross - cutting relationships to determine relative age. The other options (lava flows forming on top of one another, sedimentary layers forming over time, and fossils in different rock layers) rely on other geological principles like superposition and fossil succession.

Answer:

A fault breaks through sedimentary layers.