Geology Quiz 10

An erosional surface separating parallel sedimentary rock layers is called: a) disconformity b) basal conglomerate c) nonconformity d) boundary layer e) angular unconformity

a) disconformity

Which relative dating principle states that fragments included in a host rock are older than the host rock? a) principle of inclusion b) principle of exclusion c) principle of cross-cutting relationship d) principle of lateral continuity e) principle of superposition

a) principle of inclusion

After TWO half lives: a) 50% of the parent isotope will remain b) 25% of the parent isotope will remain c) 12.5% of the parent isotope will remain d) 6.125% of the parent isotope will remain e) All parent isotope will be gone

b) 25% of the parent isotope will remain

Radiocarbon dating is useful in dating event that occurred within the past________ a) 4 thousand years b) 40 thousand years c) 400 thousand years d) 4 million years e) 40 million years

b) 40 thousand years

When tilted or folded sedimentary rocks are overlain by more flat-lying strata, it is known as: a) A disconformity b) An angular unconformity c) A nonconformity d) A conformity e) None of the above

b) An angular unconformity

How many half lives must elapse before 75% of parent isotope becomes daughter isotope? a) One half life b) Two half lives c) Three half lives d) Four half lives e) Not enough information given to answer this question

b) Two half lives

"The present is the key to the past." This statement relates to _____ a) Catastrophism b) Uniformitarianism c) Aristotle's hypothesis d) William Smith's theory e) None of the above

b) Uniformitarianism

Which one of the following organisms is MOST LIKELY to be fossilized? (hint: think under normal circumstances) a) a butterfly in your garden b) a seashell on a beach c) a slug on a leaf d) a single-celled bacteria e none of the above will ever become a fossil

b) a seashell on a beach

How does an angular unconformity form? a) rocks are folded into an angle and the top is removed by faulting b) older rocks are tilted, eroded, and overlain by younger rocks c) rock layers are turned upside down at an angle d) angular rocks are deposited on top of flat-lying layers e) any of the above

b) older rocks are tilted, eroded, and overlain by younger rocks

An erosional surface that represents a gap in the geologic record is called: a) basal conglomerate b) unconformity c) boundary layer d) lamination e) marker horizon

b) unconformity

The half life of an isotope is 10,000 years. If 12.5% of the parent isotope remains in the rock by the time it is dated, how old is the rock? a) 10,000 years b) 20,000 years c) 30,000 years d) 40,000 years e) Not enough information given to answer this question

c) 30,000 years

Radiocarbon is ____________ a) carbon-12 b) carbon-13 c) carbon-14 d) both carbon-13 and carbon-14 e) none of these

c) carbon-14

an erosional surface between a plutonic igneous or metamorphic rock and sedimentary (or volcanic) rock is called: a) disconformity b) basal conglomerate c) nonconformity d) angular unconformity e) marker horizon

c) nonconformity

What factors are the most critical in determining whether a fossil is preserved? a) the age of the fossil and the age of sediments in which it is preserved b) the temperature of the granite and how fast it cooled c) whether the creature had hard parts and how fast it was buried d) the color of the original organism compared to the color of the sediments in which it is found e) whether the creature was a predator or was prey

c) whether the creature had hard parts and how fast it was buried

Based on current data, the age of Earth is about ____________ a) 2 billion years b) 4.6 million years c) 16 million years d) 4.6 billion years e) 195 million years

d) 4.6 billion years

Which one of the following is NOT a fossil? a) an insect trapped in amber 20 million years ago b) a frozen mammoth preserved in a glacier in Siberia that died in the last ice age 1 million years ago c) dinosaur footprints in a sandstone layer d) an Egyptian death mask dating back to 4000 years e) all of the above are fossils by definition

d) an Egyptian death mask dating back to 4000 years

Which of the following features look like fossils but are not? a) footprints from dinosaurs and other creatures b) burrows excavated by worms and other creatures and filled by other sediment c) leaves and other plants formed on land d) dark minerals that grow in branching patterns e) all of the above are fossils

d) dark minerals that grow in branching patterns

An index fossil must be: a) limited to a particular region b) very rare c) long-lived in terms of geologic time d) easily identifiable in the field e) all of the above

d) easily identifiable in the field

Fossils are common in: a) volcanic igneous rocks b) plutonic igneous rocks c) metamorphic rocks d) sedimentary rocks e) all rock types

d) sedimentary rocks

Which of the following is NOT a way in which fossils can be preserved? a) they can be replaced by hard materials, such as silica b) they can be buried and decay, leaving a cavity in the rock c) they can be preserved in ancient tree sap d) they can be too small to see but can build diagnostic features in the rocks e) all of the above are ways a fossil can be preserved

e) all of the above are ways a fossil can be preserved

The time it takes for a given amount of radioactive isotope to be reduced by half is called: a) atomic life b) atomic mass life c) atomic spin life d) nuclear magnetic life e) half life

e) half life

The principle of cross-cutting relationship states that: a) the older layers in an undeformed sedimentary rock sequence will be at or near the bottom of the sequence b) all sedimentary rock layers were originally horizontal c) if fragments of rock "A" is found within rock "B", then rock "A" is older than rock "B" d) all sedimentary rock layers originally extended in all directions e) if a sequence of sedimentary rock is disrupted by a fault or an igneous intrusion, then the fault or the igneous intrusion is younger than the disrupted layers

e) if a sequence of sedimentary rock is disrupted by a fault or an igneous intrusion, then the fault or the igneous intrusion is younger than the disrupted layers

A very short-lived, geographically widespread fossil species that existed during a specific interval of geologic time is called _______ a) assemblage fossil b) range fossil c) age fossil d) interval fossil e) index fossil

e) index fossil

Which relative dating principle states that the youngest layer in a sedimentary rock sequence is on the top of the sequence and the oldest layer is at the bottom of the sequence? a) principle of inclusion b) principle of original horizontality c) principle of cross-cutting relationship d) principle of lateral continuity e) principle of superposition

e) principle of superposition