Question 1

What is the important limitation of the K/Ar radiometric clock?

Accepted Answer

Because Ar is a noble gas it is not bound in the mineral lattice and can diffuse out or escape after it forms, especially at high temperature or in surface weathering.

Question 2

Which of the following denotes the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas?

Accepted Answer

A)   strata typing
B)   correlation
C)   cross- cutting
D)   radioactive intuition B

Question 3

Which have been around longer, the benthonic foraminifera or planktonic ones?

Accepted Answer

Benthonic since Paleozoic, planktonic since Mesozoic (mainly Cretaceous)

Question 4

A few rare times in earth history the majority of life forms disappeared "clearing the ecologic slate" for new ones. When this happens it is called_________ .

Accepted Answer

A)   an iridium anomaly
B)   a mass extinction
C)   an ecoshift
D)   a half life

Question 5

Which type of microfossils have a tooth- like shape made of apatite, are a mouth part of an extinct swimming eel- like chordate, and are useful index fossils for the Paleozoic through Triassic?

Accepted Answer

A)   conodonts
B)   acritarchs and dinoflagellates
C)   diatoms and radiolaria
D)   coccoliths and formaminifera

Question 6

Which of the following means to recognize, identify, and describe similar- aged strata or similar lithologies in nearby areas or in widely separated, different areas?

Accepted Answer

A)   strata- titling
B)   fossicking
C)   coagulation
D)   correlation

Question 7

What geologic law/principle states that fossil organisms (fauna) changed and evolved in a definite, progressive way such that strata of specific ages can be recognized by the fossils they contain?

Accepted Answer

A)   fossil exhibitionism
B)   fossil transubstantiation
C)   fossil superposition
D)   fossil succession

Question 8

Who made the first clear statement of the law of superposition? When?

Accepted Answer

A)   Nicolaus Steno, 17th century
B)   George Dawson, 19th century
C)   Charles Edward Stuart, 17th century
D)   William Smith, 18th century

Question 9

The rare element iridium has been implicated in which "ancient health" crisis?

Accepted Answer

A)   poisoning of primitive algae in the Hadean Eon
B)   disappearance of Neanderthal man during the early Cenozoic Era
C)   extinction of the woolly mammoths in late Pleistocene time
D)   extinction of the dinosaurs at the end of the Cretaceous Period

Question 10

Which geologic event or feature has the crucial contact relations to help you determine that fault B is younger than fault A, even though they don't directly contact each other?

Accepted Answer

The answer of Which geologic event or feature has the...

Question 11

What is the Jurassic Period named after?

Accepted Answer

A)   19th century Canadian geologist Sir William Jurass
B)   the Jurassic Park movies
C)   a moon of Saturn
D)   Jura Mountains between France and Switzerland

Question 12

Visualize (or draw) five, horizontal, sedimentary strata as exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?

Accepted Answer

A)   bed 3 is older than beds 2 and 4
B)   bed 4 is older than bed 2
C)   bed 5 is the oldest
D)   beds 1 and 3 are older than bed 4

Question 13

Which English engineer and amateur geologist (his first name was William) is generally credited with first demonstrating the principle of faunal succession from his observations in building canals?

Accepted Answer

A)   Smith
B)   Blake
C)   Wordsworth
D)   Tell

Question 14

The ________is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can uniquely determine geologic ages of strata.

Accepted Answer

A)   law of fossil regression
B)   law of correlative indexing
C)   principle of cross correlation
D)   principle of fossil succession

Question 15

What kind of unconformity is the most common and why?

Accepted Answer

The answer of What kind of unconformity is the most...

Question 16

Why is the major branch of the K- 40 decay to Ca- 40 not useful in most cases for whole rock dating?

Accepted Answer

A)   It only works 89% of the time.
B)   Ca- 40 is itself unstable and further decays to more daughter products.
C)   The Ca- 40 that is produced by decay is indistinguishable from the naturally most abundant isotope of Ca that may have been present initially.
D)   The decay to Ar- 40 is faster and has wider geologic applicability.

Question 17

Which rocks are most useful in unraveling Earth's geologic history?

Accepted Answer

A)   meteorites
B)   fossiliferous sedimentary rocks
C)   high grade metamorphic rocks
D)   phaneritic igneous rocks

Question 18

Which of the following denotes the divisions of the geologic time scale in correct order of decreasing lengths of time, beginning with the longest time interval and ending with the shortest?

Accepted Answer

A)   eon, era, epoch, period
B)   eon, epoch, period, era
C)   eon, era, period, epoch
D)   era, period, epoch, eon

Question 19

What is the age of the Earth accepted by most scientists today?

Accepted Answer

A)   4.6 billion years
B)   about 4600 thousand years
C)   4.6 million years
D)   540 billion years

Question 20

The task of matching geologic formations of the same age over vast distances (like between continents) is termed __________.

Accepted Answer

A)   correlation
B)   lithification
C)   cross dressing
D)   stratification

Exam 19: Shorelines