Geology

Front 1

TRUE OR FALSE:
(metamorphic rocks)
Non-foliated= minerals are lined up

Back 1

FALSE: minerals are lined up= foliated

Front 2

this texture indicates coarse grains

Back 2

phaneritic

Front 3

this texture indicates fine grains

Back 3

anphanetic

Front 4

this texture indicates a mix of phaneritic and anphanetic

Back 4

prophyritic

Front 5

this texture indicates unordered ions

Back 5

glassy

Front 6

the large crystals in a rock with a porphyritic texture are called _______.

Back 6

pheoncrysts

Front 7

the small crystals in a rock with a porphyritic texture are called _______.

Back 7

groundmass

Front 8

______ cooling promotes the growht of fewer, but larger crystals

Back 8

slow

Front 9

TRUE OR FALSE:
igneous rocks are most often classified by their texture and mineral compostion

Back 9

true

Front 10

igneous rocks that form when molton rock solidifies AT THE SURFACE are classified as _______.

Back 10

extrusive

Front 11

igneous rocks that form at depth are called _______.

Back 11

intrusive

Front 12

TRUE OR FALSE:
Feldspar makes up the ocean crust as well as lava flows and volcanic structures on land.

Back 12

FALSE: basalt

Front 13

what can greatly affect both the size and arrangement of crystals in an igneous rock?

Back 13

the rate of cooling

Front 14

_______ is the tendency of a mineral to break along planes of weaker bonding

Back 14

cleavage

Front 15

___________ may occur when rock ascends as a result of convection upswelling, thereby moving into zones of lower.

Back 15

decompression melting

Front 16

subduction zones are which type of plate boundry?

Back 16

convergent

Front 17

this type of volcano is smaller and usually located in the continental crust and above sea level in oceans

Back 17

cinder cone

Front 18

thys type of volcano is larger and located in continental margins. it has some expolosive events

Back 18

composite cone

Front 19

these volcanoes are huge, and are located along ocean basin. they have relatively quiet eruptions composed mainly of basalt

Back 19

shield volcano

Front 20

a _______ boundry is normally devoid of volcanism

Back 20

transform

Front 21

the _________ is the relatively rigid zone above the asthenosphere that includes the crust and the upper mantle

Back 21

lithosphere

Front 22

vents that emit only hot gases and vapors are called

Back 22

fumeroles

Front 23

this type of lava is rough and jagged

Back 23

Aa

Front 24

this type of lava is smooth and can resemble twisting ropes in braids

Back 24

pahoehoe

Front 25

this type of lava in composed of elongated structures that indicate lava flow formed underwater

Back 25

pillow

Front 26

TRUE OR FALSE:
The more silica in magma, the greater the viscosity

Back 26

true

Front 27

TRUE OR FALSE:
basaltic lavas tend to be quite fluid

Back 27

true, it has high silica content

Front 28

very destructive event, meaning glowing avalanche.

Back 28

nuee' ardentes

Front 29

destructive flow occurs when volcanic debris becomes saturated with water and rapidly moves down steep volcanic slope. volcano does not need to be erupting for this to happen

Back 29

lahar

Front 30

a structure that results from the emplacement and crystallization of magma beneath the surface

Back 30

plutons

Front 31

said to be this if it cuts across existing structure

Back 31

discordant

Front 32

said to be this if it forms parallel to features such as sedimentary strata

Back 32

concordant

Front 33

this is said to be the most important agent in metamorphism

Back 33

heat

Front 34

3 agents involved in metamorphism

Back 34

heat, pressure, chemically active fluids

Front 35

this means that temperature increases with depth

Back 35

geothermal gradient

Front 36

when magma intrudes relatively cool rocks at shllow depths, host rock is baked

Back 36

contact metamorphism

Front 37

this is used to describe size, shape, and arrangement of grains within a rock

Back 37

texture

Front 38

type of foliation characteristic of coarse grained metamorphic rocks

Back 38

shistocity

Front 39

texture in which dark and light silicate minerals are separated giving the rock a banded appearance

Back 39

gneissic texture

Front 40

this foliated metamorphic rock is very fine grained and closely resembles shale

Back 40

slate

Front 41

this consists of tilted or folded sedimentary rocks that are overlain by younger, more flat lying strata. indicates that tilting or folding may have occured

Back 41

angular unconformity

Front 42

represents a long period where depostition ceased, and then resumed

Back 42

unconformity

Front 43

type of unconformity where strata on either side are esssentially parallel

Back 43

disconformity

Front 44

typy of unconformity where the break separates older metamorphic rock or igneous rock from younger sedimentary strata

Back 44

nonconformity

Front 45

the time required for half of the nuclei to decay

Back 45

half life