Exam 3

Question 1

When did dinosaurs become extinct

Answer 1

66 million years ago

Question 2

What is the law of uniformitarianism

Answer 2

The present is the key to the past

the theory that changes in the earth’s crust during geological history have resulted from the action of continuous and uniform processes.

Question 3

which is the longest period of time

Answer 3

precambrian

Question 4

All geologic periods of time

Answer 4

1. Cenozoic:
   1. Quatemary
   2. Tertiary
2. Mesozoic
   1. Cretaceous
   2. Jurassic
   3. Triassic
3. Paleozoic
   1. Permian
   2. Carboniferous (1.
   Pennsylvanian 2.
   Mississippian)

     3. Devonian 
     4. Silurian 
     5. Ordovician 
     6. Cambrian

Question 5

which era was the age of the dinosaurs?

Answer 5

Mesozoic

Question 6

which is the current geologic era?

Answer 6

Cenozoic

Question 7

Which isotope do we use to date events that occurred in the past 50,000 years?

Answer 7

carbon

Question 8

if we have one quarter of the radio-active isotope parent left, how many half lives have passed?

Answer 8

2

Question 9

what is the name of the radioactive decayed product?

Answer 9

the daughter

Question 10

how old is the earth?

Answer 10

4.5 billion years

Question 11

who is the father of geology

Answer 11

James Hutton

Question 12

unconformity?

Answer 12

gaps in the geologic rock record. They are surfaces of contact between older rocks and younger sedimentary rocks, formed due to erosion or lack of sediment deposition over extended periods of time.

Question 13

what is the principal of faunal succession?

Answer 13

based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.

Question 14

which radioactive method is used to date organic remains?

Answer 14

radio-carbon, the carbon nitrogen

Question 15

What is the definition of half life?

Answer 15

The time required for one-half of the radioactive (parent) isotopes in a sample to decay to radiogenic (daughter) isotopes.

The time it takes mothers to make daughters

Question 16

if you start out with 1,000 radioactive isotopes, after 2 half lives how many do you have left?

Answer 16

250

Question 17

what was the highest form of life in the precambrian era?

Answer 17

bacteria

Question 18

what forms of life existed in the precambrian era?

Answer 18

bacteria

Question 19

what is the name of the Mesozoic supercontinent?

Answer 19

Pangea

Question 20

approximately how many large lithospheric plates do we have?

Answer 20

12

Question 21

how old are the oldest oceanic basalts?

Answer 21

200 million years

Question 22

what type of a plate boundary is the san Andreas fault

Answer 22

transform

Question 23

In what kind of a plate boundary do we find submarine trenches and volcanic island arcs

Answer 23

collision, or a convergent

Question 24

which continents are a part of Gondwanaland?

Answer 24

Africa, south america, Antarctica, Australia, subcontinent of india. All southern continents.

Question 25

what did vine and matthews explain about seafloor spreading?

Answer 25

they discovered the magnetic anomalies on the ocean floor. (magnetic stripes or magnetic reversals)

Question 26

what is the orientation of the magnetic stripes on the ocean floor? which way do they go?

Answer 26

Parallel to the ridge, mirror image

Question 27

how did the andes mountains form?

Answer 27

Collision of 2 lithospheric plates

Question 28

what causes plate tectonics?

Answer 28

thermal convection generated by heat

Question 29

what is Iceland part of?

Answer 29

its part of the mid-atlantic ridge

Question 30

what was the name of the guy that originated Pangea?

Answer 30

alfred wegener

Question 31

what kind of evidence did he use to prove pangea?

Answer 31

fossils, glacial deposits, rock formations, geographic fit

Question 32

why was his theory rejected?

Answer 32

they did not have the right mechanism

Question 33

below what temperature do you have to cool the iron rich basaltic to magnetize it?

Answer 33

the magma curie point (500 degrees celsius)

Question 34

where would you find the youngest ocean floor basalts in the ocean?

Answer 34

by the ridge. they get progressively older the further away from the ridge you go

Question 35

what kind of a boundary is the Himalayas?

Answer 35

conversion, collusion, compression

Question 36

what is the definition oftransform boundary?

Answer 36

plates sliding past each other laterally

Question 37

what is the definition of lithosphere?

Answer 37

the upper most regent part of the mantle and crust.

Question 38

are volcanoes distributed evenly everywhere or do they occur along plate bound boundaries?

Answer 38

volcanoes are located along plate boundaries