Geologic Time Answers

oceans✔ fossilsthe atmosphere

✔ PrecambrianPaleozoicCenozoic

✔ 1 2 3 4

1 2 ✔ 3 4

Use the drop-down menus to match each description to the geologic era it describes.

How are eras and periods of the geologic time scale named?

before ✔ after during

From what material did the moon form?

Fill in the blanks to complete each statement about the age of Earth. According to scientific evidence, Earth is approximately 4.6 ⇒ billion years old. Scientists used dating to determine Earth’s age.

Order these events from oldest (1) to most recent (4). Dense melted material sank to form the core. Earth’s gravity captured gases to form the first atmosphere. Dust, rock, and ice were pulled together by gravity. Less dense material cooled, hardened, and formed the crust.

Use the drop-down menus to match each description to the geologic era it describes. The first birds and flowering plants appeared during this era. This is also when the most well-known dinosaurs lived. Mammals, including humans, emerged during this era. At the beginning of this era, animals lived only in water. By the end, some early dinosaurs emerged.

Which processes produced heat that contributed to the formation of Earth’s different layers? Check all that apply.

1 2 3 ✔ 4

Paleozoic Mesozoic ✔ Cenozoic

✔ PaleozoicMesozoic Cenozoic