Quiz #5

6 September 2011

S.I. Session 5 Quiz

This quiz covers material from the lecture on Monday, September 5th.

Part a) Match the term to its definition:

                TERMS:

a) Late Jurassic                  b) Magnetic Time Scale                 c) Stratified

d) Negative                        e) GPS                                                  f)Late Cretaceous/Early Tertiary

g)Positive                            h)Early Jurassic                                  i) Whole Mantle

                DEFINITIONS:

1)__This has been constructed by analyzing hundreds of volcanic lavas on land.

2)__These magnetic anomalies occur where the mid-ocean ridge lavas cooled while the geomagnetic field was of “normal” polarity.

3)__In this time period, the ancient Tethys Ocean began to contract.

4)__In this time period, it became noticeable that India was moving towards Eurasia.

5)__In this time period, there were two giant landmasses: Gondwana and Laurasia.

6) __ In this model of convection, plate recycling extends to the core mantle boundary.

7) __ These magnetic anomalies occur where the mid-ocean ridge lavas cooled while the geomagnetic field was of “reversed” polarity.

8) __ This technology is the modern equivalent of “navigating by the stars”.

9) __ In this model of convection, plate recycling is confined to the upper mantle.

Part b) True or False:

                Mark T (true) or F (false) in the blank provided:

                                1)__The oldest seafloor rocks are the same age as the earth itself.

2)__Marine magnetic anomalies are geophysical evidence for seafloor spreading.

3)__Rock layers can indicate the direction of the earth’s magnetic field at the time when they were formed.

4)__GPS requires two satellites to pinpoint a location accurately.

5)__The Baja Peninsula has separated 500 km from Mexico in the past 5 million years.

6)__The deepest earthquakes take place at about 700 km beneath the earth’s surface.

7) __There are currently two theories concerning the nature of the mantle convection system.

8) __ Copper is the element that gives rocks their magnetic behavior.

9) __ The seafloor is made up of alternating bands of normal and reversed magnetized rocks

10) __ The spreading history of the sea floor can be played back like a magnetic tape recording.

11) __ Drilling into the seafloor has confirmed that the age of the seafloor decreases with increasing distance from the mid-ocean ridge.

12) __ The radius of the earth is 700 km.