Exam 1 - Historical Geology

Glass is a mineral

false

What type of sedimentary rock is made of sand-sized particles?

sandstone

Metamorphic rocks are altered by which of the following

all of the above

the term metamorphic means forward from fire

false

a mineral has to be solid substance

true

What type of metamorphism is defined by alteration of rock over a large area by hear and pressure due to deep burial or tectonic processes?

Regional metamorphism

what is another term for intrusive rock?

Plutonic rock

What is the definition of magma?

melted rock below the surface of the Earth

What is the difference between intrusive and extrusive rocks?

location of where the rock cools

What type of metamorphism is defined by alteration of rock by heat and chemically active fluids adjacent to hot molten lava or magma? Pressure is less of an influence.

Contact metamorphism

Sedimentary rocks can tell us about the ancient environment and climate where these rocks formed.

true

what is the difference between felsic and mafic rocks?

amount of ferromagnesian (Fe and Mg) minerals

minerals don’t have to have a well-defined chemical composition

false

precambrian time encompasses 87% of geologic history

true

a radioactive daughter element is unstable and undergoes radioactive decay to form a stable parent element

false

radioactive elements do not always decay at a constant rate.

false

why is it tricky to age date sedimentary rocks?

all of the above

what is the farthest c-14 dating can go back?

60 to 80 thousand years

choose the correct sequence of eras in the phanerozoic eon

paleozoic>mesozoic>cenozoic

what determines the atomic mass of an atom?

number of protons plus neutrons

list the geologic time units in order from greatest (left side) to least (right side)

eons>eras>periods>epochs

the number of this atomic particle changes depending on the isotope

nucleus

the determines the atomic number of an atom?

the number of protons

What is actually dated during C-14 dating?

how many years ago the organism died

what is the smallest particle of matter that can exist as a chemical element?

atom

what is a half-life?

the time it takes half of the parent atoms to turn into daughter atoms.

nothing can affect the radioactive decay rate.

true

after 2 half-lives, what will the percentage of parent to daughter?

25% parent, 75% daughter

what is the term when there is an unequal number of protons and electrons in an atom?

ion

what does lateral continuity refer to?

original sedimentary layers will extend laterally until it tapers or thins at edges

the only way to explain a change in fossils over time was a global catastrophe.

false

who developed the principles of superposition, original horizontally, and lateral continuity?

Nicolaus Steno

Individuals with the most favorable traits are more likely to survive and reproduce.

true

fossils occur in a consistent vertical order in sedimentary rocks all over the world

true

what does original horizontality refer to?

sediments deposited in water formed as horizontal or nearly horizontal layers

what did the Neptunists believe?

all rock a formed from a great ocean

which phrase best defines the principle of cross-cutting relationships?

the thing that does the cutting is younger than the thing being cut

What does superposition refer to?

rock layers are progressively younger upward in the stack

what is an unconformity?

an ancient erosion or non-deposition separating older rocks from younger rocks.

which of the following is not a type of rock?

migmazoan

what is the scientific theory that is attributed to Charles Darwin?

natural selection

What did the Plutonists believe?

Fire or heat was the origin of primitive igneous rocks

What year was radioactivity discovered?

1896

a theory is

a well-established explanation of a set of observations

what does geochronology refer to?

the science that deals with determining the ages of rock

which phrase best describes absolute age?

quantifying the age of rock in years

which of the following is not a type of tectonic plate boundary movement?

revergent

which of the following is appropriate order of things in the Scientific Method?

question, hypothesis, observation, theory

where is the lithosphere located?

the outermost portion of the Earth

natural selection included the concept of

survival of the fittest

which phrase best describes relative age?

determining the sequence of rock formation

radioactive age dating predates the development of the geologic timescale

false

radioactive elements can be used as geological clocks

true

where is the asthenosphere located?

under the lithosphere

rigid tectonic plates float on the asthenosphere

true