The earth is estimated to be about 4.5 billion years old. Rocks and rock formations found throughout earth’s crust give scientists clues to the past. They assume that the processes that acted on the crust millions of years ago are the same processes that act on and within earth today. This is called the principle of uniformity or uniformitarianism.

The law of superposition helps us infer the age of rock layers, or strata. This law states that, if layers of rock are left undisturbed, the layers at the bottom are the oldest. The lower layers must be in place before younger layers can be deposited on top of them. Scientists infer the relative age of the layers as well as any fossils found within them. The law of superposition does have exceptions. Some processes within the earth cause younger layers to be moved below older. Folding, faulting, and intrusion can cause these exceptions. Regardless of position, any rock is always older than the process that changed it.
Geologist infer that the fossils number 3 and 5 are approximately the same age. This assumption of relative age is based on what information from the passage?

Hi there!

Since the passage said that older fossils are most likely underneath newer ones, we can conclude that both fossils were buried at similar depths of ground in similar places.

Hope this helps!

Answer Link

JuliettaGlassford JuliettaGlassford · Answer 2 · 2019-10-09T07:18:48+02:00

Answer:

It is based on the law of superposition to infer the age of rock layers and there by determining the age of fossils present in it.

Explanation:

From the passage, the law of superposition states that lower is the layer of rock, older is its age. We can determine the relative age of rock layers with the help of this law, if the the rock layers are not disturbed during the course of time.

Since fossils can be observed in these rock layers we can use the technique of relative dating to determine the relative age of fossils. In this method, we can reasonably say that the fossils found closer to the surface of earth are the more recent ones than the fossils found in the deeper layers of rock.

Fossils found in the same layer of rock can be supposed to be of same age. This relative dating method is useful to compare the ages of fossils but we cannot precisely find it.