Quiz #14

3 October 2011

S.I. Session 14 Quiz

This quiz covers material from the lecture on Friday, September 30^th.

Part a) Match the term to its definition:

                TERMS:

a)Absolute Dating                            b)Mass Extinctions          c) Paleozoic

d)Sequence Stratigraphy              e)Isochron                          f)Cenozoic

g)Radioactive Decay                       h)Half Life                           i) Mesozoic

                DEFINITIONS:

1)__Major boundaries in the geologic time scale represent these.

                                2)__This is the earliest third of the geologic time scale, its name means “old life”.

3)__A geological reconstruction based on analyzing seismic imaging data.

4)__This is an intrinsic property of an isotope and is independent of pressure and temperature.

5) __This process involves a parent atom emitting an electron and a daughter atom producing a proton.

6)__ This is the middle third of the geologic time scale, its name means “middle life”.

7)__This is based on the decay of unstable radioactive isotopes, discovered by Becquerel in Paris in 1896.

8)__ This is the latest third of the geologic time scale, its name means “new life”.

                9)__ Minerals of the same age can be plotted on this line.

Part b) Short Answer

1)      If the ratio of parent to daughter material in a rock is originally 1000:100, what will the ratio of parent to daughter material be after 3 half-lives?

2)      If there are originally 32,000 grams of parent material in a rock sample, and the half-life of this parent material is 16,000 years, then after how many years will there be only 2,000 grams of parent material left?

3)      In question 2, how much daughter material is present at the end of all of the elapsed half-lives?

Part c) True or False:

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

                                1)__The rate of radioactive decay is measured by the half-life.

2)__Half-life is defined as the amount of time it takes for the parent material in a radioactive sample to double.

3)__The isotope strontium 86 is radioactive.

4)__Earth’s oldest material is a Zircon crystal that is 4.4 billion years old and is located in Australia.

5)__The geologic time scale was derived from the fossil record.

6)__The preserved rock record is 90% complete, unconformities represent gaps in the rock record.

7)__The sequence stratigraphy technique is used in the Gulf of Mexico to find deeply buried oil and gas.