Question

question 14 of 20 : select the best answer for the question. 14. a geologist discovers fossils of marine animals in a layer of sedimentary rock in the desert. based on this discovery, what conclusion can the geologist draw? a. the layer of rock must have been subjected to tectonic forces. b. the fossils are the remnants of organisms that are now extinct. c. the region where the rock was discovered was once underwater. d. the layer of rock is younger than the layer of rock above it. mark for review (will be highlighted on the review page) << previous question next question >>

Explanation:

• Option A: Tectonic forces relate to rock movement/deformation, not directly to marine fossils in a desert. The presence of marine fossils doesn't necessarily mean tectonic forces acted on the rock layer.
• Option B: The fossils being of marine animals doesn't imply they are extinct. Many marine species still exist, so this conclusion isn't supported.
• Option C: Marine animals live in water, so finding their fossils in a desert (now dry) suggests the region was once underwater (where the animals lived and were fossilized). This is a logical conclusion.
• Option D: The principle of superposition states that in undisturbed rock layers, the older layer is below the younger one. But the discovery of marine fossils doesn't provide information about the relative age of this layer to the one above; it's about the environment, not relative dating.

Answer:

C. The region where the rock was discovered was once underwater.