GEOL 1404 Review Outline- Exam 2

You are responsible for studying all material discussed in class or assigned as reading material, this is just a suggested

study guide.

**Lessons 8, 9 - Precambrian**

1. What percentage does the Proterozoic, Archaean and Hadean, take up compared to the Phanerozoic

**Percentage of Precambrian vs. Phanerozoic**: The Proterozoic, Archaean, and Hadean together make up about 88% of Earth's history, while the Phanerozoic (the time when complex life forms appear) makes up the remaining 12%.

2.What was plate tectonics like when earth first formed

**Plate Tectonics**: When Earth first formed, plate tectonics were likely very different from what we see today. The crust was probably more solid and less broken into separate plates.

3. When and where are the first valid known rocks from

**First Valid Known Rocks**: The first rocks we have evidence of are from the Archaean era, around 4 billion years ago, found in places like Greenland and Western Australia.

4. What was significant about the igneous rock types of the Archean

**Significance of Archean Igneous Rocks**: The igneous rocks from the Archean are significant because they provide evidence of the early formation and cooling of Earth's crust.

5. What is a greenbelt

**Greenbelt**: A greenbelt refers to a belt of greenstone rocks, which are typically volcanic and sedimentary rocks that are associated with ancient oceanic crust.

6.What land masses make up Laurentia

**Land Masses of Laurentia**: Laurentia is made up of North America, Greenland, and parts of Scotland and Ireland.

7. What are ophiolites and why are they important

**Ophiolites**: Ophiolites are sections of oceanic crust and mantle that have been uplifted and exposed on land. They are important because they provide insights into the processes occurring at mid-ocean ridges.

8. What is the shield platform and craton

**Shield Platform and Craton**: The shield platform and craton are stable areas of continental crust that have not been significantly deformed for billions of years.

9. When and where are the first valid fossils from

**First Valid Fossils**: The first valid fossils are from around 3.5 billion years ago, found in Western Australia.

10. What is a Wilson Cycle

**Wilson Cycle**: The Wilson Cycle describes continental drift's cyclical process, including supercontinents' formation and breakup.

11. What do single-celled organisms need to be able to do to become living bacteria

**Single-Celled Organisms to Bacteria**: Single-celled organisms need to develop the ability to metabolize organic molecules and reproduce to become living bacteria.

12. What was the Grenville Orogeny, and geologically when and where was it located

**Grenville Orogeny**: The Grenville Orogeny was a major mountain-building event that occurred around 1 billion years ago in what is now eastern North America.

13.What is photosynthesis

**Photosynthesis**: Photosynthesis is the process by which plants and some bacteria convert light energy into chemical energy, producing oxygen as a byproduct.

14. What is outgassing

**Outgassing**: Outgassing refers to the release of gases from the Earth's interior, which contributed to the early atmosphere.

15. Why is earths oldest time difficult for scientists to study

**Difficulty Studying Earth's Oldest Time**: Earth's oldest time is difficult to study because much of the early rock record has been destroyed or altered by geological processes over billions of years.

16. What is tectonically active and passive? What parts of Laurentia were undergoing tectonics during the Precambrian

**Tectonically Active and Passive**: Tectonically active regions experience frequent earthquakes and volcanic activity, while passive regions have relatively stable crust. During the Precambrian, parts of Laurentia were both tectonically active and passive.

17. How did our atmosphere and ocean form and were they habitable for life

**Atmosphere and Ocean Formation**: Earth's atmosphere and ocean formed through processes like outgassing from volcanic activity and the condensation of water vapor. They were likely not immediately habitable for life as we know it.

18. What is accretion

**Accretion**: Accretion is the process of particles coming together to form larger bodies, such as planets.

19. Were there glacial periods during the Proterozoic and if so where

**Glacial Periods in the Proterozoic**: Yes, there were glacial periods during the Proterozoic, particularly in regions like the Huronian Supergroup in North America.

20.What does all life come from

**Origin of Life**: All life on Earth is believed to have originated from simple single-celled organisms.

21. What were the first fossil organisms like

**First Fossil Organisms**: The first fossil organisms were likely simple, single-celled organisms like bacteria and algae.

22. What data is used to do paleogeographic reconstructions

**Paleogeographic Reconstructions**: Paleogeographic reconstructions use various types of data, including fossil evidence, rock formations, and magnetic signatures, to reconstruct past continental configurations.

23. What is the Edicarian fauna

**Edicarian Fauna**: The Edicarian fauna refers to a group of early, soft-bodied multicellular organisms that lived around 635 to 541 million years ago.

24. What are the names of the first two supercontinents and when did they occur

**First Two Supercontinents**: The first two supercontinents were Rodinia, which formed around 1.3 billion years ago, and Pangaea, which formed around 335 million years ago.

**Lessons 10, 11 - Paleozoic**

1. What are the Sauk, Tippecanoe, Absoroka and Kaskaskia sequences defined by

**Sequences Defined by**: The Sauk, Tippecanoe, Absoroka, and Kaskaskia sequences are defined by different sedimentary layers deposited during specific time periods in the Paleozoic.

2. When and where are many coal beds found in the Paleozoic

**Location of Coal Beds**: Many coal beds in the Paleozoic are found in areas that were once swamps or marshes, such as parts of North America and Europe.

3. What are the Black shales and why are they important, what are they missing

**Black Shales**: Black shales are dark-colored sedimentary rocks that are important because they often contain fossils and can provide clues about past environments. They are missing significant amounts of oxygen.

4. What is the Paleozoic supercontinent

**Paleozoic Supercontinent**: The Paleozoic supercontinent was called Pangaea.

5. What is a cyclothem and why are they important

**Cyclothems**: Cyclothems are cyclical patterns of sedimentary rock layers that represent changes in sea level and climate over time. They are important for understanding past environmental changes.

6. Was there any glacial activity in the Paleozoic, if so where

**Glacial Activity**: Yes, there were glacial periods during the Paleozoic, particularly in the southern hemisphere.

7. What is a mobile orogenic belt

**Mobile Orogenic Belt**: A mobile orogenic belt is a region where mountain-building processes are actively occurring.

8. What and where is an epeiric sea

**Epeiric Sea**: An epeiric sea is a shallow inland sea that covers a large portion of a continent.

9. What mobile belts are active in the Paleozoic in North America

**Active Mobile Belts in North America**: During the Paleozoic, active mobile belts in North America included the Appalachian Mountains and the Antler and Sonoma orogens in the western United States.

10.What was the old red sandstone and Catskill delta, where were they

**Old Red Sandstone and Catskill Delta**: The Old Red Sandstone and Catskill Delta were sedimentary rock formations deposited during the Devonian period in regions that are now parts of North America and Europe.

11. What and where were Panthalassa and Iapetus Oceans

**Panthalassa and Iapetus Oceans**: Panthalassa was the vast ocean surrounding Pangaea, while the Iapetus Ocean was located between Laurentia and Baltica.

12. Where can the Ouachita mountains be seen

**Ouachita Mountains**: The Ouachita Mountains can be seen in Arkansas and Oklahoma in the United States.