Midterm Review Questions

Question 1

How do we know the outer core is liquid*** test question

Answer 1

Because Shear waves cannot pass through the core thus the core must be liquid. This can be determined through Shadow zones, which are created when S waves refract off a certain angle of the outer core.

Question 2

Define seismogaphs and seismograms***test question

Answer 2

Seismographs record seismic waves, ***remember seismic waves travel at different speeds.
seismogram: records of seismic waves,

Question 3

Define Focus and Epicenter and their relationship**test question

Answer 3

Focus is where that energy or slippage started

The epicenter is the point of the earths surface that is directly above the focus.

Question 4

How did Banded Iron Formations play into the development of life*** test question

Answer 4

A factor for the GOE
iron remained in solution in the non-oxygenated environment of the earlier Archean Eon. In chemistry, this is known as a reducing environment. Once the environment was oxygenated, iron combined with free oxygen to form solid precipitates of iron oxide, such as the mineral hematite or magnetite. These precipitates accumulated into large mineral deposits with red chert known as banded-iron formations, which are dated at about 2 billion years.
The formation of iron oxide minerals and red chert (see figure) in the oceans lasted a long time and prevented oxygen levels from increasing significantly, since precipitation took the oxygen out of the water and deposited it into the rock strata. As oxygen continued to be produced and mineral precipitation leveled off, dissolved oxygen gas eventually saturated the oceans and started bubbling out into the atmosphere. Oxygenation of the atmosphere is the single biggest event that distinguishes the Archean and Proterozoic environments

Question 5

Angular disconformity ** mid term question, on the previous midterm. Grand Canyon

Answer 5

where sedimentary strata are deposited on a terrain developed on sedimentary strata that have been deformed by tilting, folding, and/or faulting. so that they are no longer horizontal

The Phanerozoic strata in most of the Grand Canyon are horizontal. However, near the bottom horizontal strata overlie tilted strata. This is known as the Great Unconformity and is an example of an angular unconformity. The lower strata were tilted by tectonic processes that disturbed their original horizontality and caused the strata to be eroded. Later, horizontal strata were deposited on top of the tilted strata creating the angular unconformity

Question 6

What are the principles of relative time dating

Answer 6

Principle of Cross-Cutting Relationships,
Principle of Inclusions,
Principle of Fossil Succession,

Question 7

Define Principle of Cross cutting relationships

Answer 7

Principle of Cross-Cutting Relationships: Deformation events like folds, faults and igneous intrusions that cut across rocks are younger than the rocks they cut across.

Question 8

Why study paleontology

Answer 8

A way to bring fossils back to life

Question 9

What is the GOE*** possible question

Answer 9

The Great Oxygenation Event
A period of the early Proterozoic (around 2.5-2 billion years ago) where atmospheric oxygen levels dramatically increased, killing many non-oxygen-breathing organisms and allowing oxygen-breathing organisms to thrive

Question 10

Define GSSPs

Answer 10

Global Boundary Stratotype sections and points

Question 11

How much matter does hydrogen make up in the universe

Answer 11

74%

Question 12

What are the empirical lines of evidence to explain the big bang theory

Answer 12

Stellar Evolution
Redshift
Cosmic Microwave Background radiation
Spectroscopy

Question 13

Define the Nebular Hypothesis and Bowens Reaction Series*** possible question

Answer 13

The spinning nebular cloud accumulated heavy and light elements in space, close to the center the temperature was so high that only some metals and silicate minerals formed thus rocky planets were created closer to the center and as the temperatures were cooler farther out, allowing condensation of lighter gaseous molecules to accumulate into planets.

Question 14

Define Strike and Dip *****possible test question

Answer 14

Geologists use a special symbol called strike and dip to represent inclined beds. Strike and dip map symbols look like the capital letter T, with a short trunk and extra-wide top line. The short trunk represents the dip and the top line represents the strike. Dip is the angle that a bed plunges into the Earth from the horizontal. A number next to the symbol represents dip angle.

Question 15

What are the blocks on either side of a fault called*** possible question

Answer 15

Any rocks above the fault are called: Hanging wall

Any rocks below the fault are called: the Footwall

Question 16

Learn the anatomy of the fold****

Answer 16

Folds are described by the orientation of their axes, axial planes, and limbs. The plane that splits the fold into two halves is known as the axial plane. The fold axis is the line along which the bending occurs and is where the axial plane intersects the folded strata. The hinge line follows the line of greatest bend in a fold. The two sides of the fold are the fold limbs.

Question 17

Define Horst and Graben*** possible question

Answer 17

Grabens, horsts, and half-grabens are blocks of crust or rock bounded by normal faults. Grabens drop down relative to adjacent blocks and create valleys. Horsts rise up relative to adjacent down-dropped blocks and become areas of higher topography. Where occurring together, horsts and grabens create a symmetrical pattern of valleys surrounded by normal faults on both sides and mountains.

Question 18

What is the date of the base of the Paleozoic

Answer 18

541 million years ago

Question 19

Explain and Define the Cretaceous-Paleogene Boundary

Answer 19

Line of evidence suggesting an asteroid impact occurred in the Yucatan, around 60% of all know animals became extinct. A deposit of 1cm of clay with a high iridium content marks the boundary of Cretaceous and Paleogene.

Question 20

What is the date of the base of the Mesozoic and Paleozoic boundary

Answer 20

251.902(MA) million years ago

Question 21

What is the base of the Cenozoic and Mesozoic boundary

Answer 21

66 MA or million years ago

Question 22

When did the End Permian Mass Extinction occur

Answer 22

252 MA (million years ago)

Question 23

Define and explain the process of lithification

Answer 23

The process of turning sediment into a sedimentary rocks. The steps are as follows deposition, compaction, and cementation.

Question 24

Define the Protolith and how it plays into metamorphic rocks

Answer 24

The rocks that existed before the changes that lead to a metamorphic rock, i.e. what rock would exist if the metamorphism was reversed.

Question 25

What are the periods and epochs of those periods in the Cenozoic. He said to know these for the test.

Answer 25

66MA to 23MA - Paleogene
- Paleocene 
- Eocene
-Oligocene
23MA-2.58 MA- Neogene
-Miocene
-Pliocene
2.58 - .01171 MA - Quaternary
- Plesioscene 
- .01171 - Holocene