A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms. The researcher could estimate the age of this fossil based on
A) the amount of carbon-14 in the fossil.
B) the amount of uranium-238 in the fossil.
C) the amount of carbon-14 in the sedimentary rocks in which the fossil was found.
D) the amount of uranium-238 in volcanic layers surrounding the fossil.
E) the amount of uranium-238 in the sedimentary rocks in which the fossil was found.

Question

Quizplus · Accepted Answer

The most accurate way to estimate the age of a fossil is through radiometric dating. Carbon-14 dating is only effective for fossils up to 50,000 years old, while the age of the oldest-known multicellular organisms is much older than that. Carbon-14 dating is also not as reliable for sedimentary rocks. Uranium-238 dating is reliable for rocks and fossils that are millions of years old. Uranium-238 is commonly found in volcanic layers surrounding sedimentary rocks, making it the best choice for dating the oldest-known multicellular organisms.

A Researcher Discovers a Fossil of What Appears to Be