Geology

Question 1

What is a fossil?

Answer 1

A fossil is any trace of life preserver in rock

Examples: footprint, feces, bone, leak, she’ll of an organism

Question 2

What is the law of superposition?

Answer 2

The law of superposition if the geological principle that in horizontal layers of sediment rock, each layer is older than the layer above and younger than the layer below.

Question 3

What is geological time?

Answer 3

Geologic time is the eras and the order of how fossils progressed

Question 4

What are the eras in geologic time?

Answer 4

Early pre Cambrian
4,500 to 3,800 mya
No fossils to date

Late pre Cambrian
3,800 to 550 mya
First fossils of multicellular organisms (bacteria, algae, earliest aquatic animals)

Early Paleozoic
550 to 408 mya
Fossils with shells
(Fungi, early fish, brachipods)

Late Paleozoic
408 to 245 mya
The extinction of many fossils (early land plants, amphibians, insects and reptiles)

Mesozoic
245 to 65 mya
Dinosaurs and early flowering plants

Cenozoic
65 mya to present
Birds, large mammals, and early grasses

Question 5

When does a geologic era start or end?

Answer 5

The beginning and the end of geologic time periods are determined with the appearance or disappearance of organisms (fossils)