Focuses on two chapters:
Plate tectonics and Geologic time
When did dinosaurs become extinct?
● Asteroid theory: An object approximately 10 kilometers across struck just off the coast of the Yucatan peninsula 65 million years ago
● Volcanism theory: Some scientists think the decline rate of the dinosaur species is stored within the remnants of long-dormant volcanoes.
● Massive beds of ancient lava found around the world depict an Earth 65 to 70 million years ago where volcanic eruptions were commonplace. We also discuss several other topics like What does john bowlby think of children's attachment?
During which era did the dinosaurs exist?
● The Cretaceous period
What is the name of the current geologic era?
● Cenozoic era
Who is the father of geology?
● James Hutton 1726-1797
How old is the earth?
● According to Archbishop James Ussher, the earth was created at midday on october 23rd, 4004 BC and is 6,000 years old.
● Charles Darwin in 1859 estimated 300 million years.
What is an unconformity?
● a contact between two rock units in which the upper unit is usually much younger than the lower unit. Unconformities are typically buried erosional surfaces that can
represent a break in the geologic record of hundreds of millions of years or more. (not sure about the definition gave in class, this is what I got from google)
If you want to learn more check out What are the five forces of newton's three laws?
Which radioactive isotope is used to determine the age of events that occured in the past 50,000 years?
● The carbon-14 method
What is the term used for the decay product for a parent isotope? If you want to learn more check out Where should tracheal tubes be located?
● Daughter isotope
*What was the highest form of life in the proterozoic?
What is uniformitarianism?
● same processes operating today occurred in the past
● strata deposited on older crystalline (metamorphic/igneous) rock We also discuss several other topics like What is the sign for each element in the periodic table?
● erosion surface on igneous/metamorphic rock covered by sedimentary rocks ● large gap in geologic record
Fact: the precambrian is the longest era
*Periods of the paleozoic (know them)
What is faunal succession?
● Fossil assemblages succeed each other in time.
What is half life?
● When half a life period has elapsed. (300 million becomes 150 million) If you had a billion isotope how many would be left after one half life? ● 500 million We also discuss several other topics like What makes europe a very biodiverse continent?
Which radioactive isotope is used to date organic remains?
● Uses radiocarbon-14 to estimate the age of organic remains.
What are we made out of?
● oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus
Approximately how many large plates exist
● 12, a dozen
How old is the oldest oceanic floor
● 180 million years old
What type is of boundary is the san andreas
● Subduction zone- they form at convergent boundaries if at least one side has oceanic (denser) material
*Know the continents of gondwana
What did vine and matthew try to prove?
● magnetic anomalies
● In the 1950s electronic magnetometers were developed, which could be towed behind an airplane or a ship. Oil companies were soon using them aboard airplanes, mapping the weak magnetism of rocks to help locate oil deposits. On land, the patterns of this magnetism seemed jumbled, with no meaningful order.
● Extending those measurements to the oceans, around 1960, revealed a surprising difference. In the ocean floor the magnetization was orderly, arranged in long strips. The strips on the Atlantic ocean floor, in particular, all seemed parallel to the "mid-Atlantic ridge." We also discuss several other topics like How did women's roles change during the war?
What is the orientation of the magnetic anomalies on the ocean floor? How are they oriented? ● parallel to the ocean ridges
How did the indeas mountain formed?
● conversion plate boundaries
● The Andes mountains along the western edge of the South American ● continent are an example of a mountain belt formed by subduction. ● The continental crust of the South American plate has buckled under the compressional
● strain. Additionally there are many volcanoes, the result of melting of the subducting slab
● and the production of new material that has risen through the crust to the surface. What causes plates to move?
● Mantle convection: Hotter mantle material rises beneath divergent boundaries, cooler material sinks at subduction zones.
● So: moving plates, earthquakes, & volcanic eruptions are due to Earth’s loss of internal heat.
● part of the mid atlantic rift
Who originated the continental rift theory?
● alfred wegener- 1915
● Supercontinent Pangaea started to break up about 200 million years ago. ● Continents "drifted" to their present positions.
● Continents "plowed" through the ocean crust.
● Pangaea about 200 million years ago, before it began breaking up.
Wegener named the southern portion of Pangaea Gondwana, and the northern portion Laurasia
Why was his theory rejected?
● Rejected in U.S., where scientists staunchly preferred induction (incremental progress built on observation) over what they perceived as speculative deduction. ● Lack of a suitable mechanism crippled continental drift’s widespread acceptance. ● Conflict remained unresolved because seafloors were almost completely unexplored *Know when basalts become magnetized and at what temp
What is the lithosphere?
● the outermost layer of the crust
What forces created the himalayas?
● Collision zones form where both sides of a convergent boundary consist of continental (buoyant) material
● This probably used to be a subduction zone, but all the oceanic material was subducted
What is a transform plate boundary?
● Most transform boundaries are in the oceans.
● Some, like the one in California, cut continents.
● The San Andreas Fault is an example of a transform boundary between the Pacific plate and the North American plate.