Question

Read the passage and answer the question.

In 2000, when paleontologist Paul Sereno led an expedition into Ténéré desert in Niger looking for the fossils of dinosaurs and ancient crocodiles, the photographer Mike Hettwer wandered away from the group to take pictures of some dunes near the main dig site. The photographer quickly found bones sticking out of the dunes, but they were human bones, not the prehistoric reptile bones the group had been looking for. However, the group was not going to pass up such an amazing discovery.
During the site excavation, the paleontologists found dozens of gravesites. Some of them held skeletal remains and potsherds with wavy lines etched in them. The scientists named this group the Kiffians. The others held skeletal remains that indicated a taller group of people, and their potsherds were decorated with patterns of dots. The scientists named this group the Tenerians. The graves also contained tools and beads made from stones or bones, as well as refuse heaps containing the bones of the animals the people living in the area had consumed. Some of the graves didn't contain any pottery so it was a mystery which group they belonged to. It was also not known when these people lived in the desert or how they survived.
The carbon-14 dating revealed that the Kiffians lived in the area around 9,700 years ago, and then the area was abandoned until the Tenerians lived in the area 7,000 years ago. The scientists want to reconstruct what the land looked like when it was inhabited, as well as understand why there was about a 2,000-year-gap during which nobody lived in the area.
The scientists hypothesize that the two civilizations lived around a lake that dried up during periods of drought and then eventually reformed. The changing lake led people to move, depending on if they had a water source or not.
How can scientists use radiometric dating to reconstruct the geologic history of the area to support or reject their hypothesis of a disappearing and reappearing lake? What is a tool that scientists can use to ensure that their radiometric dating is accurate?

Answer 1

Answer & Explanation:

Scientists can use radiometric dating to reconstruct the geologic history of the area and support or reject their hypothesis of a disappearing and reappearing lake by analyzing the sediments and other geological features present in the area. Radiometric dating, such as carbon-14 dating, can determine the age of the sediments, fossilized remains, and other materials. By analyzing the age and composition of these materials, scientists can track changes in the environment over time, including periods of drought or increased precipitation that could cause a lake to dry up or reform.

To ensure the accuracy of their radiometric dating, scientists can use calibration methods, such as cross-dating with other dating techniques like dendrochronology (tree-ring dating), or comparing their results with well-dated samples from similar or nearby environments. This can help validate the radiometric dating results and provide more confidence in the reconstructed geologic history and any conclusions drawn from it regarding the presence or absence of a lake in the area at different times.

Answer 2

Scientists can use radiometric dating to reconstruct the geologic history of the area and support or reject their hypothesis of a disappearing and reappearing lake. They can use an isochron diagram as a tool to ensure the accuracy of radiometric dating.

In order to support or reject their hypothesis of a disappearing and reappearing lake, scientists can use radiometric dating to reconstruct the geologic history of the area. Radiometric dating is a technique that uses the decay of radioactive isotopes in rocks to determine the age of the rocks and the fossils within them. By dating different rock layers and fossils, scientists can create a timeline of when the lake existed and when it dried up.

A tool that scientists can use to ensure the accuracy of radiometric dating is called an isochron diagram. An isochron diagram plots the ratio of parent isotopes to daughter isotopes in a rock sample, and if the rock sample falls along a straight line, it indicates that the radiometric dating is accurate. If the rock sample falls off the line, it may indicate that the sample has been contaminated or there was a problem with the dating process.