chap 2 test

The contact beneath the Tapeats Sandstone and the underlying Grand Canyon Supergroup is an example of a(n)

disconformity.

what country produces most of the worlds opal?

Australia

How many points of "attachment" does a single carbon atom possess?

4

The oldest radiometric date reported for an individual mineral grain from a sedimentary rock is approximately _____.

4.4 billion years

Evidence indicates the age of the solar system to be approximately _____ years old.

4.56 billion

What percentage of opal is colorless?

95%

_____ is useful for dating organic materials.

Carbon-14

Based on the block diagram below, the igneous intrusion labeled B is younger than Unit 2. What stratigraphic principle allowed you to determine this observation?

Entry field with correct answer principle of superposition principle of faunal succession principle of original horizontality principle of cross-cutting relationships - CORRECT answer

n the block diagram below, the contact between rock unit 4 and the underlying rock unit 3 is an example of a(n)

Entry field with incorrect answer disconformity. - CORRECT answer nonconformity. angular unconformity. a conformable depositional contact.

The geologic era in which animals with hard shells first appeared is the

Paleozoic.

For the stratigraphic section of the Grand Canyon depicted in the photograph below, which rock unit is older?

Tapeats Sandstone

What is at the very heart of the issue of global warming?

The carbon atom

For the block diagram below, which of the following statements is(are) true?

a) The igneous intrusion labeled B is older than Unit 2. b) The igneous intrusion labeled B is younger than Unit 2. c) The igneous intrusion labeled B is younger than the tilted sequence 1. d) Both A and C are true statements. e) Both B and C are true statements.- CORRECT answer

for the block diagram below, what type of unconformity is labeled as 2? (stage 5)

angular unconformity

The value of the mineral opal is based on __________.

color

In the block diagram below, the contacts between layers in the tilted stratigraphic sequence labeled 1, are examples of

disconformities. nonconformities. angular unconformities. conformable depositional contacts. - CORRECT answer

For the block diagram below, what type of unconformity is labeled as 3? (stage 5)

disconformity

In the stratigraphic sequence of the Grand Canyon, depicted below, the contact between the Muav Limestone and the overlying Redwall Limestone spans two missing periods of geologic time. The contact between these two stratigraphic units represents a(n)

disconformity.

in the block diagram below, the contact between rock unit 4 and the underlying intrusion B is an example of a(n)

disconformity. nonconformity. - CORRECT answer angular unconformity. a conformable depositional contact.

The genus Australopithecus evolved from the genus Homo.

false

For the block diagram below, what type of unconformity is labeled as 1? (stage 5)

nonconformity

In the block diagram shown below, deformation of the stratigraphic sequence labeled 1

occurred prior to 34 million years ago. before the intrusion of the igneous rock body labeled B. before the deposition of unit 2. all of the previous statements are true. - CORRECT answer

When we see sedimentary rock units that are twisted or tilted, we know that some force must have disturbed the strata after they were deposited. The principle upon which we base this inference is the principle of _____.

original horizontality

If you see a vertical magmatic intrusion embedded in horizontal layers of sedimentary rocks, which principle will help you determine the relative age of the intrusion?

principle of cross-cutting relationships

What is the principle that helps geologists determine the age of rocks that are separated by distance?

principle of lateral continuity

What principle would allow you to determine the relative ages of different parts of the stratigraphy of this section of the Grand Canyon?

principle of superposition

or the block diagram below, what stratigraphic principle allowed you to determine the relative age of the intrusion and the stratigraphic sequence labeled 1?

principle of superposition principle of faunal succession principle of original horizontality principle of cross-cutting relationships - CORRECT answer

Periods of geologic time lasted for

tens of millions of years.

Rocks are taken from the Moon's surface are believed to be original crust because _____.

the moon is geologically inactive

The principle of stratigraphic superposition tells us that _____

the oldest rock strata in any undisturbed sedimentary sequence are on the bottom, and the youngest are on the top.

An unconformity is a gap in the stratigraphic sequence.

true

Geologists have divided the three eras of the Phanerozoic Eon into a number of shorter units called periods.

true

Lord Kelvin based his estimate of Earth's age on how long it must have taken Earth to cool by conduction.

true

The Allende meteorite is classified as a carbonaceous chondrite.

true

Numerical age is the age of a rock or geological feature in years.

ture

The film suggests that the Portuguese eggs were blooded and probably closer to

warm; birds

Colorless opals are ______________?

worthless