Strata & fossils

Question 1

What are fossils?

Answer 1

Fossils are the remains of animals and plants(also footprints and burrows) that are generally found in sedimentary rocks.

Question 2

Fossils not only give us information about the different forms of life that had existed on Earth but they also tell us about major changes in the Earth’s history.

Answer 2

True.

Question 3

Explain strata.

Answer 3

The sedimentary rocks is usually arranged in layers, so it’s called strata.

Question 4

What is stratigraphy?

Answer 4

The study of rocks and layering(strata).

Question 5

How many techniques can scientists use to help date the layers in the sedimentary rocks?

Answer 5

3 techniques

Question 6

Explain technique #1

Answer 6

The principle of superposition says that the oldest layer is at the bottom and the youngest at the top. Therefore, the fossils on the lower layer is older then the one above it.

Question 7

Explain technique #2

Answer 7

Geologists also use relative dating, a technique used to determine the order of which events took place. Although, it does not prove the exact age of the rock, it does tell us which layer is older. example: if a fault is running through them.

Question 8

Explain technique #3

Answer 8

Absolute dating is a process by which the age of the fossils or rock layers is calculated by carbon dating. This calculates the amount of carbon-14 or uranium present in rocks to determine the exact age.