Proterozoic Snowball and Rodinia

Question 1

What are the characteristics of continents

Answer 1

• Formed by Cratons
• Not just land above sea level, edges can be submerged
• Granitic crust, thicker than ocean crust

Question 2

Define Supercontinents

Answer 2

Two or more continents that have joined

Question 3

Through what can supercontinents be identified

Answer 3

Ophiolites

Question 4

Define Ophiolites

Answer 4

indicate plate convergence

Question 5

What is the oldest documented supercontinent

Answer 5

Rodinia

Question 6

Define Rodinia

Answer 6

assembled 1.0-1.3 billion years ago
-began fragmenting about 750 million years ago

Question 7

What happened to pieces of Rodinia

Answer 7

Reassembled into the supercontinent Pannotia about 650 million year ago
-Pannotia fragmented about 550 million years ago

Question 8

What happened when Rodinia was being formed

Answer 8

Ancient glaciers and their deposits

Question 9

What are the processes of Snowball Earth

Answer 9

1. oceans start freeze
2. low reflectivity, causes more cooling, ending in snowball earth
3. Co2 in ocean stops, Co2 outgassed by volcanoes builds up
4. Strong greenhouse effect melts snowball earth
5. Co2 cycle restarts, bringing Co2 into oceans

Question 10

How did snowball earth end

Answer 10

• Volcanoes adding Co2 into atmosphere
• Movements of continents to higher latitudes

Question 11

What happened during the Proterozoic life

Answer 11

• Abundant bacteria and Archaea
• Cyanobacteria become more abundant
• Appearance of Eukaryotes

Question 12

Define Symbiosis

Answer 12

relationship between 2+ organisms where both benefit

Question 13

Define endosymbiosis

Answer 13

One symbiont lives within another
(no fossil evidence for this)

Question 14

What is the Oldest known Eukaryote

Answer 14

Bangiomorpha
1.2 Ga

Question 15

What are the benefits of Multi-celled organisms

Answer 15

• Cells perform specialized tasks

Question 16

When did multicellular organisms come to be

Answer 16

Existed in Neoproterozoic, likely earlier
- no record of fossils of how they came to exist

Question 17

What were Ediacaran Fauna

Answer 17

• First animals
• lived 635-545 million years ago
• Found around the world but fossils are not common

Question 18

What is found in a Ediacaran environment

Answer 18

• Hard parts found in Ediacaran fauna

Question 19

What does the Ediacaran Environment show

Answer 19

First evidence of simple ecological interactions

Question 20

What 3 modern groups did the Ediacaran environment represent

Answer 20

• Phylum Cnidaria
• Phylum Annelida
• Phylum Arthropoda