1. How old is the earth? How old did early church leaders think it was?
The Earth is 4.5 billion years old. Church leaders thought it was around 6,000 years old based on scriptures.
2. Hutton found what rock formation in Scotland was the clue to the real age of the earth?
Siccar Point on the coast of Scotland. They were rock formations that showed that the Earth was not thousands, but millions of years old.
3. Kelvin used thermal cooling calculations to determine the age for the earth-how long was this?
He estimated the Earth to be 20 million years old.
4. Why was he wrong?
Temperatures can fluctuate from additional heat produced as a result of radioactive decay, which was unknown during Kelvin's time.
5. What is "deep time"?
Time on an "incredible scale", such as in the billions of years.
6. What is so special about "pillow lavas"? What is the Hawaiian name for these?
Pillow lava is so special because they create deep tubes that solidify underwater. The Hawaiian name for them is "nahuku".
also Pahoehoe
Hawaiian names confuse me...
7. What does Zircon have to do with aging the planet? What do they tell us about the source of water?
Zircon is abundant in the Earth's crust and plays an important role in radiometric dating, containing trace amounts of uranium and thorium that can be dated.
because the half life is very long, right?
Uranium-238 has a half-life of 4.5 billion years, uranium-235 704 million years, thorium-232 14.05 billion years. So very long, indeed...
Zircon crystals from 4.4 billion years ago show evidence of contact with water, suggesting that water is already around by that time (which might have been from meteorites that bombarded the planet during this time).
8. Water is neat stuff. Why would the temperature of the earth 4 bY ago accelerate changes?
Pieces of the continental crust started appearing 4 billion years ago, around which continents cooled around and eventually formed.
right, also heat makes water reactions occur much faster
9. About 3.4 bY ago a new type of rock was formed-what is this rock, and how does it fit into the asthenosphere picture of plate tectonics?
Granite. When land masses formed, the granite formed plates for land masses to shift upon. Granite was tough enough to resist the erroding effects of the ocean, eventually forming continents.
also less dense, so they float on the asthenosphere
10. South Africa hosts the CapeVal Cretins: what are these? Why are these important? What did these have to do with the beginning of life? Where was life limited to before these?
They were some of the first land masses formed, created by volcanic activity. Here, evidence first existed for life above water, which is where all lifeforms on earth were limited to before.
11. What are stromatolites, and what did they produce? From what?
Stromatolites are accretionary structures that trap cyanobacteria and can produce oxygen using photosynthesis, expelling rocks as waste.
12. Playford found what? What is the impact of what he found?
He found fossilized stromatolites, allowing scientists to conclude that life did indeed exist far back then. All life now descended from these stromatolites at some point or another.
13. What caused the change in the color of the oceans? What then happened to the atmosphere? What color was the planet after this?
The change was caused by iron leaving the oceans. Newly arrived oxygen in the atmosphere from photosynthesis by stromatolites turned the planet from green to blue.
14. What is a trilobite, and where are they found? Why are they significant? What did they prove?
Trilobites are extinct marine fossils found in rocks all over modern continents. They are significant because they proved that tectonic shifts occured to push the continents apart to where they are now; these freshwater creatures could not have swum the vast salty oceans otherwise.
15. What did Wegener believe? How easy was this to prove? When and how was it finally proven?
Wegener proposed that the continents had once been joined together, but later drifted apart. This could be seen easily by how the modern continents fit together. His theory was finally accepted when during World War II, the United States mapped the ocean floor only to discover vast undersea mountain ranges that marked the boundary of tectonic plates.
16. What does convection have to do with plate tectonics?
Hot lava causes the plates to move.
ahh, you can be more specific. Heat from the core (product of fission) travels towards cooler space, the matter is part of that energy flow...
And so as the heat flows upwards, it hits the crusts and "splits" in two directions, carrying the plates above it with the heat flow. FYI, I didn't answer this one... *ahem*
17. Why is Iceland such an ideal place to study plate tectonics?
Iceland has fissure eruptions that happen as a result of the plates shifting apart.
Iceland was formed by volcanic activity on the mid atlantic rift zone. The fact that it is so active, combined with the sonar and then magnetic symmetry away from the mid atlantic ridge proved plate tectonics
18. What was Rodinia? Why did it cause climate change about 700 mY ago? Why is this so critical to understand today?
Rodinia was the super continent that existed before Pangaea. It triggered the formation of Snowball Earth by blocking the warm ocean currents from the equator from reaching the Earth's poles, causing a postive feedback loop when the frozen poles raised the albedo, lowering the temperature even further.
any implications about what is happening now?
Similarly, we have a positive feedback loop that is happening with the melting ice caps and lowered albedo (less solar energy reflected leading to higher temperatures which accelerates melting of the caps lowering albedo again).
19. What was the Cambrian Explosion? Why is it important? What did Walcott discover? Where? What is the Burgess Shale Quarry? Why is shale so special in this process?
The Cambrian Explosion was the rapid appearance of most major phyla based on complex fossil records due to the high concentration of oxygen in the atmosphere. This diversification of species is responsible for much of the biological diversity now. Walcott discovered the Burgess Shale Quarry in the Canadian Rockies. The Burgess Shale Quarry was special because there were lots of fossils from 500 million years ago. Shale helped to preserve the soft tissue of these fossils.
20. When did carnivores show up? Why? How did their presence change the evolution of creatures?
Carnivores showed up when sufficient oxygen levels allowed organisms to grow more complex. Now, organisms now had to evolve in face of competition from other organisms and not just from challenges posed by the environment.
21. What did the ozone shield enable the growth of? Where did the ozone come from?
The ozone shield enabled organisms to evolve outside of water. Oxygen allowed the ozone shield to form. Animals could now live on land because ozone acted as an ultraviolet shield.
right, more implications?
Thinning of the ozone layer by chemicals in the late 20th century might increase ultraviolet light exposure of all animals on the planet, leading to elevated cancer rates and other associated ailments.
22. What formed the carbon in the carboniferous era? What did life look like 60 mY ago? What does this carbon look like today?
Plants formed much of the carbon in this era. Much of the continent looked like a steamy, tropical jungle swampland. This carbon now exists in the form of coal.
23. What does the freshwater in a swamp enable? Why is this important?
Freshwater allows dead plant matter to accumulate instead of decompose. Over millions of years, with the addition of pressure, this dead matter turns into coal.
24. What did dead marine organisms transform into? Why is this important to us?
Coal, which is a major energy source now.
why then would coal also have a high level of sulfur? Look up methionine and cysteine.
Methionine and cysteine are two amino acids that contain sulfur as part of their chemical composition. Not sure what this has to do with coal... can you explain this in class?
25. What caused the first mass extinction? What is a mantle flume eruption? (:52)
250 million years ago, lava flowed to the surface of the Earth. Most animals could not survive and went extinct. A mantle flume eruption is when part of the molten mantle rises to the surface and breaks through the crust, spilling lava onto the surface.
26. What was the name of the next supercontinent?
Pangaea.
27. What were the predominant survivors of the first mass extinction?
Dinosaurs.
28. Why would Utah be a good place to find these survivors?
Paleontologists find lots of bones and fossils packed in the rocks, which often are really old.
also, very dry, little erosion (water or wind)
29. What would be the advantage of being "luke-warm" blooded?
They have the best of both worlds. Less energy has to be spent on "staying warm", therefore they can use that energy to grow big. Compared to other organisms, they are faster in the morning because they don't have to wait for the sun to warm their blood.
like the stegosaurus?
30. How did the first global warming trend change the dinosaurs? Why did this eventually become their downfall?
They were allowed to grow super big. It became their downfall because after the asteroid impact, there was not that much food or plant life. The dinosaurs eventually starved to death.
good
31. The Kimberly "stove pipe" means what? How are diamonds formed?
Kimberlite pipes are volcanic pipes formed by the eruption of deep-origin volcanoes, consisting of a core of solidified magma containing kimberlite or lamproite. Diamonds are formed through the exposure of carbon materials to high pressure underneath the continental plates.
32. Who discovered the CT (KT) boundary, and what does it signify? When was this? When was it discovered, and how?
The K-T boundary was discovered by Luis Alvarez, and signifies the transition from the Cretaceous period to the Tertiary period. This happened 65.5 million years ago, and was discovered in 1980 when Alvarez and his team noted the increase in concentration of iridium in sedimentary layers corresponding to the transition from the Cretaceous period to the Tertiary period.
33. How big was the Yucutan meteor? How was it found (look this up on wikipedia)
The meteor was estiamted to be at least 10 km in diameter. Its existence was discovered by Glen Penfield who noted shocked quartz, a gravity anomaly, and tektites in surrounding areas.
How do they know how big it is? Clues: diameter of the crater is one, estimating the thickness of the K-T layer worldwide was another...
They also mapped out gravity anomalies in the area that formed a ring roughly outlining the impact crater. Geologists are way too smart for me.
34. About 50 mY ago, the mammals evolved. How did the demise of the dinosaurs make this possible? Science fiction movies often show cavemen fighting dinosaurs-why is this totally bogus?
Mammals evovled after the demise of dinosaurs as they were the only animals alive after the K-T extinction event. Cavemen fighting dinosaurs is a scene that can only exist in fiction because humans weren't around until at least 200,000 years ago, while all dinosaurs went extinct around 65.5 million years ago.
right, so I guess the Flintstones is fiction then?
I know, that disappoints me so... the writers certainly had interesting interpretations of dinosaur-powered technology (their vehicles, for example).
35. What is similar about the Alps and the Himalayas, apart from them being mountains? What limits their ultimate altitude?
The Alps has no volcanoes and neither does the Himalayas. They were a result of tectonic plates hitting each other. Their altitude is ultimately limited by their "roots" that sink into the crust if they grow any higher.
right, they are floating on the asthenosphere
36. Mauna Loa is the largest landmass in the world. From the base of Mauna Loa on the 20,000 ft. deep ocean floor to it's top 13,500 ft. above sea level is much higher than Everest (29,000 ft.). How is this possible?
Mauna Loa is the remnant of a volcano, and so doesn't suffer from the limitation that mountains formed through tectonic plate movements have (sinking as it becomes too high).
not quite: the majority of the land mass is actually underwater, so it has some buoyancy...see?
It's also mostly igneous rocks, and so probably is more porous and less dense than other types of rocks.
37. About 2 mY ago, an ice age again struck. What triggered this? How long did it last?
The ice age was triggered by overflowing volcanoes that made land bridges cutting off warm ocean currents. Reduced albedo further lowered temperatures. It lasted for some 100,000 years.
more implications about global warming?
38. What makes glaciers flow? Do they flow faster or slower when they are thicker? Why?
Glaciers move due to a combination of surface slope and the pressure of the overlying snow and ice. Thicker glaciers have more velocity, because there is more ice to exert pressure on the ground.
not quite, ice under pressure melts (look up triple point and regelation)
Because PV = nRT! (too much thermodynamics lately...)
39. Explain the balance between temperature and the progress of glaciers.
Glaciers move faster with higher basal temperatures and vice versa.
closer to zero C, right?
40. Glaciers often leave "unsorted" rocks, called glacial "till". What does this mean? Why would this differ from normal sedimentary sorting? (hint: recall our walk up by the flume)
When ice moves, it brings rocks with it in specific layers. Normal sedimentary sorting is from the oldest layers at the bottom to the newest layers on top.
not really: ice grabs everything equally, with no regards to size. Sedimentation relies on buoyancy, density and surface area: larger stones fall out of a turbulent stream first, while clays can remain in suspension for a long time, settling only after the water becomes very still: think of the sediments in the
Mississippi delta: very fine particles, never any large rocks. Rapids are often made up of large rocks (turbulent water). Glacial till has large rocks and small rocks all mixed up, since the glaciers act like huge bulldozers...
So sedimentary sorting "sorts" by size, while glaciers just scoop up everything with no regards to size. Makes sense...
41. It is said that our civilization has been a brief, stable warm period. What does this predict for global warming/cooling?
Temperature extremes will increase, and another ice age may happen in the future.
42. What two oceans/seas will disappear when pangea ultima forms?
The Atlantic Ocean will disappear while the Indian Ocean shrinks (if not also disappear completely).
nice work
b
hoang phong
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