Chapter 12: Earth's Evolution

Question 1

The Precambrian History is broken down into what three Eon groups?

Answer 1

Hadean
Archean
Proterozoic

Question 2

Precambrian History

Answer 2

88% of earth’s history
or
the first 4 billion years of earth.

Question 3

Hadean, Archean, and Proterozoic creation?

Answer 3

1. particals melting, formed volcanic island arcs
2. crustal fragments collided and accreated to form large crustal provinces
3. larger crustal areas assembled into larger rocks, cratons. the core of modern continents

Question 4

What are ancient Continental Crust?

Answer 4

Shields and platforms

Question 5

What is a Shield?

Answer 5

large, relatively flat ancient metamorphic rock w/ stable continental interior

Question 6

What is a platform?

Answer 6

Shields which are covered by sedimentary rock

Question 7

What is a carton?

Answer 7

a Shield + a Platform

Question 8

What is a super continent?

Answer 8

large landmasses that all consist of all, or nearly all, exciting continents

Question 9

The most recent supercontinent

Answer 9

Pangaea

Question 10

The slitting and reassembling of former subcontinents have generated what?

Answer 10

Most of earth’s mountain belts

Question 11

What is the Supercontinent Cycle?

Answer 11

The idea that huge groups of land masses come together, break up, and are later recreated in a different orientation and formation….
ALL a result of sea-floor spreading!

Question 12

Creation and break-up of supercontinents changes what?

Answer 12

wind patterns and ocean currents

Question 13

The three Phanerozoic Eras?

Answer 13

Cenozoic (recent life)
Mesozoic (middle life)
Paleozoic (ancient life)

Question 14

Pangaea began to be assembled in what Era?

Answer 14

Paleozoic Era (542 mya)

Question 15

The breakup of Pangaea began where?

Answer 15

westward moving North American plate began to override the Pacific plate
Resulted in crustal deformation along western margin of NA.
Formed Sierra Nevada and Rocky Mountains

Question 16

When did the Mesozoic Era occur and what periods does it consist of?

Answer 16

248-65 mya
Triassic
Jurassic
Cretaceous

Question 17

When did the Cenozoic Era take place and what periods and epochs are in it?

Answer 17

65 mya-present day

Period 1: Tertiary
Epochs:
Paleocene, Eocene, Oligocene, Milocene, and Pliocene (old-young)

Period 2: Quaternary
Epochs:
Pleistocene and Holocene

Question 18

Isostatic uplift of Appalachians occur due to?

Answer 18

Erosion

Question 19

The Cenozoic Era?

Answer 19

(65 mya- present)
North America above sea level
US west coast was an active tectonic boundary

Question 20

What happens in the Pre-Cambrian period?

Answer 20

First known organisms appear.

Question 21

What are Stromatolites?

Answer 21

a. layered fossilized mounds of the bacteria: Cyanobacteria
b. Formed in shallow water
c. Provide ancient records of life on Earth

Question 22

What period has the first appearance of life forms with hard parts, such as shells?

Answer 22

Paleozioc

Question 23

During the Paleozoic, organisms diversified dramatically.. how?

Answer 23

1. Insects and plants moves to land
2. Lobe-finned fishes became 1st amphibians
   (Devonian)

Question 24

Footprints in the mud (now mudstone) were called what?

Answer 24

Allosaurus

Question 25

At the Mesozoic period, many reptile groups became extinct because of what?

Answer 25

A large asteroid that impacted in the Gulf of Mexico

Question 26

In the Cenozoic, mammals replace the reptiles as the dominant vertebrate life forms on land; called what?

Answer 26

Age of the Mammals

Question 27

The two main mammals groups that formed in the Cenozoic?

Answer 27

Marsupials

placentals

Question 28

When did Mammoths become extinct?

Answer 28

the last ice age (Pleistocene Epoch); they are related to modern elephants

Question 29

The Cenozoic flowering plants is called? And what did it do?

Answer 29

“Age of Flowering Plants”

A) called Angiosperms
B) Influenced evolution of birds and herbivores