Geo 101 – The Dynamic Earth
Exam 4 Study Guide
THIS IS NOT ALL INCLUSIVE – especially if you don’t fill it out fully.
1. You are expected to know basic terminology in order to answer the questions.
2. What are the types of fossilization that we covered and how do they work?
1) Frozen or dried
2) Amber or tar
- Sticky substances
3) Preserved or replaced
- Preserved: Grew it, there it is (ex: shark’s tooth)
- Replaced: Grew it, replaced by different mineral (ex: shells)
- Spaces filled by mineral
- Original wears away
- Mineral finishes filling in
- Elements in organism go away/disintegrate
- Only thing left is carbon
6) Molds and casts
- Mold: Imprint
- Cast: Replica
* Think Jell-o: Jell-o mold, and finished product is cast* 7) Trace fossils
- Trace of organisms
8) Extraordinary fossils
- Extremely rare
3. What are evolution and natural selection?
- Evolution: Change over time; fact Don't forget about the age old question of How do psychologists differentiate normal from abnormal personalities?
We also discuss several other topics like What is the relationship between myelin and the propagation speeds of action potentials?
- Natural Selection: Theory that explains that fact
4. What are some the many pieces of evidence that help us understand how organisms evolve?
- Anatomy (fossils vs modern animals)
- Atavism (an extinct feature that suddenly reappears in population - Embryology (development of organisms) Don't forget about the age old question of How did the christian reformations motivate europeans to increase their engagements with people around the world?
- Biogeography (where organisms are located)
- Homology (features in different organisms that look similar)
5. What causes extinction?
- Climate change
- Tectonic activity
- Asteroid or comet impact
- Large volcanic events
- New predators
6. You must know the definitions of the relative dating techniques (principles) we covered in class and be able to use them like we did during the class activity.
1) Original horizontality (sedimentary rock only)
- How is sediment deposited? Fairly horizontal
- Rock on bottom is oldest; rock on top is youngest - Applied only to sedimentary and undeformed rocks 3) Lateral Continuity
- Sediments are deposited in continuous layers - Can be disturbed later
4) Cross-cutting relationships
- Formation in relation to one another - Baked contact: Existing rock baked by magma intrusion - Inclusion: Existing rock surrounded by another rock
7. What do unconformities tell us?
- There was either no deposition or erosion If you want to learn more check out What is predatory pricing?
8. How do geologists use fossils for dating?
- Organisms only existed during certain time periods
9. How was the geologic column created?
- By combining stratigraphic columns from all over the world
10.How does a radioactive isotope give us a numerical age? -Radioactive decay proceeds at a known rate
11. What characteristics does an object need in order to be dated with radio isotopes?
- Particular, unweathered minerals
- Useful half-lives
12.What can be dated with radioactive methods?
- Volcanic ash
- Certain minerals
- Many more
13.What other methods can you use to determine a numerical age? - Growth rings
- Seasonal layers
14.What did we date to determine the age of the earth?
- Meteorites and moon rocks
15.Know the major events in each eon or era that we covered in class: names of supercontinents, big geological events, types of life that first appeared. (Use the handouts – they will make studying so much easier!!) • Hadean Eon (4.6-4.1 Ga) If you want to learn more check out Do continents warm more than oceans?
Don't forget about the age old question of When does maturation threat occur?
- 4.55 Ga: Formation of earth
- 4.5 Ga: Formation of moon
- 4.0 Ga: Meteor bombardment (destroyed Earth’s surface) • Archean Eon (4.1-2.5 Ga)
- Liquid water
- 3.5 Ga: First fossils (single cell)
• Proterozoic Eon (2.5 Ga to 514 Ma)
- 750 Ma: Rodinia supercontinent
- 570 Ma: Pannotia supercontinent
- Fully formed oxygen atmosphere
- 2.7 Ga: Eukaryotic evidence
- 2.1 Ga: First multi-cell fossils
• Phanerozoic Eon (514 Ma to Today)
* Early Paleozoic Era (514 to 443.7 Ma)
- Cambrian Explosion
- First vertebrate (jawless fish)
* Middle Paleozoic Era (443.7 to 358.9 Ma)
- First vascular plants
- First spiders and insects - First amphibians
- First tetrapods
* Late Paleozoic Era (358.9 to 248 Ma) - Pangaea supercontinent forms - First gymnosperms
- First reptiles
- First eggs with shells
- 248 Ma: Permian mass extinction * Early-Middle Mesozoic Era (248 to 145 Ma) - Break-up of Pangaea
- Formation of North Atlantic ocean - First swimming and flying reptiles - First turtles
- First mammals
* Late Mesozoic Era (145 to 66 Ma) - First flowering plants
- First grasses
- K-T boundary extinction (giant meteorite)
* Cenozoic Era (66 Ma to Today)
- Evolution of Humans
16.What is the extremely general history of human evolution? (What did the graph on the slide look like?)
- Humans are not all correlated
17.How do the various fossil fuels form?
- Oil and natural gas form from hydrocarbon compounds (remains of marine algae and plankton)
- Coal forms from decayed plant material with
18.In what geological formations do different fossil fuels get trapped? - Anticlines
- Salt domes
- Stratigraphic “pinch-out”
19.What methods do we use to extract fossil fuels?
- Drilling (puncture seal rock)
- Pumping (bringing oil to surface)
- Strip mining (less than 100 m deep)
- Underground mining (more than 100 m deep)
20.Are we running out of oil? What are the various answers to this question? - If we keep living life the way we do then yes, we are running out of oil.
- If we find alternatives to oil then no, we are not running out.
21.What are the drawbacks of fossil fuel use?
- Air pollution
- Carbon dioxide
- Fatalities during extraction
22.What are the types of alternative energy we covered? What are their advantages and drawbacks?
• Nuclear power
- Advantages: No running out
- Disadvantages: Controlling nuclear reaction; nuclear waste • Wind
- Advantages: Clean
- Disadvantages: must have steady breeze; noisy; ugly; hazard to wildlife • Solar
- Advantages: Clean
- Disadvantages: Not efficient or cost-effective (yet) • Hydroelectric
- Advantages: No pollutants
- Disadvantages: dams
- Advantages: no pollutants
- Disadvantages: construction
- Advantages: never goes away
- Disadvantages: conditions limited
- Advantages: increase oxygen
- Disadvantages: can increase food costs
23.What are ores, how do they form, and how do we use them? - Ores are rocks with high metal content
- They are used for their metal content
1) Magmatic Formation (partial melting then settling) 2) Hydrothermal Formation (hot water dissolves mineral metal) 3) Sedimentary (chemical precipitation)
4) Placer (in flowing water, heavy minerals drop around same area)
24.How do we extract mineral resources and what are the drawbacks? - Ores are mined, while rocks are quarried
- Drawbacks: mine runoff; groundwater contamination; acid rain; fatalities
I announced in class when we deviated from the textbook. Please remember, as stated in the syllabus, that when the lecture and textbook deviate from each other, the lecture is where you should get your information.
Extra office hours for exam prep:
Monday, November 14 from 12:00-2:00pm (if these don’t work, email for an appointment)