Relative Dating
What is relative dating, and how does it help scientists determine the age of fossils?
What is "relative dating determines the age of fossils based on their position in the rock layers compared to other fossils or rocks"?
What must happen for an organism to become fossilized?
What is "the organism must be buried quickly by sediment, which helps preserve its remains"?
What is the largest division of time on the geologic time scale?
What is "eon"?
What can the presence of a marine fossil in a rock layer on top of a mountain suggest?
What is "that the area was once covered by an ocean or sea"?
What is absolute dating, and how does it differ from relative dating?
What is "absolute dating provides a specific age of a rock or fossil, while relative dating only shows whether one is older or younger than another"?
What principle states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom?
What is "the Law of Superposition"?
How does the process of mineralization work in fossil formation?
What is "minerals from water replace the organic material in an organism’s remains, turning it into a fossil"?
What event marks the boundary between the Paleozoic and Mesozoic eras?
What is "the mass extinction event that wiped out many marine species"?
If scientists find fossils of a particular species in rock layers at multiple locations, what can they conclude?
What is "that the species lived over a wide geographic area at that time"?
What type of rock is most commonly used in absolute dating?
What is "igneous rock"?
If a fault cuts through several layers of rock, which is older: the fault or the rock layers?
What is "the rock layers are older than the fault"?
What is one reason why soft-bodied organisms are less likely to become fossils than organisms with hard parts?
What is "soft-bodied organisms decompose more easily, leaving fewer traces behind"?
In which era did dinosaurs become dominant?
What is "the Mesozoic era"?
How can scientists use index fossils to determine the relative age of rock layers?
What is "index fossils are found in many places but existed for a short period, helping scientists match the age of rock layers"?
What is radiometric dating, and how is it used to determine the age of rocks?
What is "radiometric dating measures the decay of radioactive isotopes in rocks to determine their age"?
Why can’t scientists use relative dating alone to determine the exact age of a fossil?
What is "because relative dating only shows whether one fossil is older or younger than another, not the exact age"?
How can fossils provide evidence of ancient environments?
What is "fossils can show the types of plants and animals that lived in an area, indicating the climate or environment"?
What is one reason the Precambrian time is so difficult to study?
What is "because most organisms were microscopic and soft-bodied, leaving few fossils"?
Why are fossil records incomplete, and how does this affect the study of ancient life?
What is "not all organisms fossilize well, and many have been destroyed by natural forces, leading to gaps in the record"?
Why can’t we use carbon-14 dating on rocks that are millions of years old?
What is "carbon-14 decays too quickly, and its half-life is too short to measure the age of very old rocks"?
A scientist finds a fossil of an ancient fish below a layer with a fossil of a reptile. What can the scientist infer about the relative ages of the two fossils?
What is "the fish fossil is older than the reptile fossil"?
Why are trace fossils, such as footprints, important for understanding ancient life?
What is "they provide clues about how an organism behaved and moved, even if no body parts are preserved"?
How do scientists divide the Phanerozoic eon into manageable time periods?
What is "by significant changes in life forms, such as the appearance and extinction of species"?
What does the discovery of a fossil in the middle of two layers of rock indicate about the relative age of the fossil?
What is "the fossil is younger than the bottom layer but older than the top layer"?
How does the use of tree rings help in absolute dating?
What is "tree rings can be counted to determine the exact age of a tree, and in some cases, they can be used to date wooden artifacts or structures"?