question

light that's caused by living things.

answer

bioluminescence

question

Geologists learn about Earth’s history by studying _____.

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rocks

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Scientist ____ _____ realized two processes were at work on Earth—one that forms rock and one that tears it down

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James Hutton

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Hutton developed the principle of _____, which states that the processes at work today are the same processes that have been at work in Earth’s past.

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uniformitarianism

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The ___ ___ is a series of processes that make and change rocks through heating, melting, cooling, uplift, weathering, burial, and increasing pressure.

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rock cycle

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Geologists categorize rocks into three groups based on how the rock ____.

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formed

question

The three rock groups are: _____, ____, and ____

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igneous metamorphic sedimentary

question

Igneous rock forms when ____ solidifies.

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magma

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Different types of igneous rocks are identified by the size of the _____ they contain

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crystals

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_____ crystals form from slow cooling

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Large

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___ crystals form from rapid cooling

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small

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____ ____ is any rock subjected to extreme pressure or heat.

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Metamorphic rock

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____ can cause minerals to become more tightly packed.

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Pressure

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Heat can cause minerals to ____ and form a new rock mineral

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recrystallize

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____ ____ form from sediments

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Sedimentary rocks

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____ are tiny particles of eroded rock

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Sediments

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Sedimentary rocks form in a four-step process: ____, ____, ____, and ____.

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weathering transportation deposition lithification

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____ is the physical or chemical breakdown of rock into smaller pieces.

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Weathering

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____ occurs when sediments are moved downhill by running water, wind, movingice, and gravity.

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Transportation

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Individual sediment grains are called ____

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clasts

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During transportation, clasts become ____ as they wear down and break apart.

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smaller

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As the speed of the sediment carrier slows down, _____-_____ clasts drop out.

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larger-sized

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____ occurs when sediments carried by water, wind, and glaciers stop moving

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Deposition

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The sediments form ____, horizontal layers

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parallel

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____ occurs when sediments become compacted and cementation changes thesediments into rock.

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Lithification

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Layers of rock are called ____

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strata

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Danish physician ____ ____ presented four principles to help geologists study strata and interpret the rock’s history.

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Nicolas Steno

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The four principles are ____, ____, ____, and ____.

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superposition original horizontality original lateral continuity crosscutting relationships

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The principle of ____ states that in a stack of undisturbed sedimentary rock layers, the layers on the bottom were deposited before the layers on top

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superposition

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The rock layers on the bottom are ____ than the layers farther up.

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older

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____ ____ tells how old something is compared to something else

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Relative age

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The principle of ____ ____ states that rock layers are originally deposited in horizontal, or nearly horizontal, layers.

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original horizontality

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The principle of ____ ____ ____ states that sedimentary rocks form layers that cover large areas.

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original lateral continuity

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The principle of ____ ____ states that a rock layer or feature that cuts across other rock layers is younger than the ones being cut.

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crosscutting relationships

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____ are made up of protons, electrons, and neutrons

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Atoms

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Isotopes of an atom have the same number of protons, but different numbers of ____

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neutrons

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Isotopes of an element may be stable or ____

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unstable

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____ ____ occurs when a nucleus gains or loses protons or neutrons

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Radioactive decay

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The gain or loss of protons or neutrons is called ____

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radiation

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Radioactive decay occurs ____ and at a regular rate

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automatically

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____ decay (an element in all living things) is used in the dating of once-living organisms

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Carbon

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The unstable isotope that decays is called the ____ ____, and the stable atom that forms is called the daughter isotope.

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parent isotope

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____ is the science of comparing annual tree ring growth to date events andchanges in past environments.

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Dendrochronology

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A ____ ____ is a layer of wood cells produced in one year

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tree ring

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Some of the factors affecting the width of tree rings are rainfall, temperature, sunlight, and ____.

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disease

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____ is a technique that gives each tree ring an exact-year date of formation

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Crossdating

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Ernest Rutherford and Frederick Soddy discovered that parent isotopes decay into daughter isotopes at a ____ ____

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constant rate

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A ____-____ is the amount of time for half of a specific amount of parent isotopes to decay into daughter isotopes

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half-life

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Geologists can determine the ____ ____ of rock by calculating the absolute age of theminerals that compose it.

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absolute age

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The ____ ____ of a mineral is determined by measuring its parent-to-daughter isotoperatio.

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absolute age

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The decay rate of radioactive isotopes is used by geologists as a “____ ____.”

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natural clock

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____ ____ is the procedure used to calculate the ages of rocks and minerals

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Radiometric dating

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____ rocks are most commonly used for radiometric dating

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Igneous

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Determining the age of ____ rocks is difficult

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metamorphic

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Geologists rarely use radiometric dating for ____ rocks

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sedimentary

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The oldest rocks on Earth are part of areas called ____ ____.

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continental shields

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Earth is at least as old as the zircon discovered by geologists in Australia in 2001, which was estimated to be _._ _billion years old.

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4.55

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Meteorites collected in ____ have been calculated to be between 4.48 and 4.56 billion years old.

answer

Antarctica

question

Rocks from the ____ have been calculated to be approximately 4.6 billion years old

answer

Moon

Life Science Chapter 7: The Age of Earth – Flashcards

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