Geology Geologic time (Game time)

Which of the following is the best statement of the principle of original horizontality?

Sediments are deposited as horizontal layers.

An undeformed sedimentary layer is ______ than the layer above and ______ than the layer below.

older; younger

The principle of superposition states that

undisturbed sedimentary layers get progressively younger from bottom to top.

Fossils are most common in which rock types?

Sedimentary

What is an unconformity?

a gap in the geologic record

A disconformity is

an erosional surface between horizontal layers of sedimentary rocks.

Which of the following is an erosion surface that separates two sets of sedimentary layers with nonparallel bedding planes?

angular unconformity

When did the Mesozoic era begin?

251 million years ago

Almost nine-tenths of Earth's history occurs during the

Precambrian.

Which of the following statements regarding radiometric dating is true?

Carbon-14 cannot be used to date material more than 100,000 years old.

Which of the following can change the rate of radioactive decay?

Not chemical reactions, Changes in pressure, or temperature

A rock formed with 1000 atoms of a radioactive parent element, but contains only 250 radioactive parent atoms today.  If the half-life for the radioactive element is one million years, how old is the rock?

2 million years old

Radiometric dating is least useful for dating __________ rocks.

Sedimentary

Human beings (homo sapiens) evolved during which geologic era?

Cenozoic

The absolute age of a geologic event in the rock record is

the number of years that has elapsed between the event and the present day.

Abrupt changes in the faunal succession in the rock record represent

 

mass extinction events

The largest mass extinction event in Earth’s history took place at the end of

The permian

A radioactive isotope has decayed to the point that one-eighth of the original content is left.   How many half-lives have passed?

3

The half-life of a radioactive isotope is

the time it takes for half of the radioactive atoms to decay.

A radioactive element inside has been decaying for 2 million years?  Given that the half-life is 500,000 years, what percent of the parent is currently left?

6%

Who came up with the principle of faunal succession?

William Smith

Who invented the geologic map?

William Smith

The first geologic map covering an entire country was for

England

Before the division of the geologic time scale into eons, the Hadean, Archean, and Proterozoic eons were collectively called

Precambrian time

Stanley Miller's experiments to explore life-building chemical reactions that took place on the primitive Earth were able to generate

Amino acids

Photosynthesis became an important metabolic process approximately _____ years ago.

2.5 billion

The initial rise of oxygen in the Earth's atmosphere is linked to

photosynthesis

The radiation of life at the beginning of the Phanerozoic eon is known as the

Cambrian explosion

____ is the process whereby animals change and adapt to new environments.

Natural selection

When organisms are no longer able to adapt to environmental changes they

become extinct

The impact site for the giant Cretaceous-Tertiary asteroid is known as the ______ crater.

Chicxulub

The tendency for variations in current velocity to segregate sediments on the basis of particle size is called

Sorting

Which of the following lists is written in order of decreasing particle size?

conglomerate, sandstone, shale

What is the general process by which rocks are broken down at Earth's surface?

Weathering

Which of the following minerals is most stable at Earth's surface?

Hematite

Which of the following minerals is least stable at Earth's surface?

Olivine