Geology Test 1

Front 1

transform plate boundaries are typically associated with

Back 1

divergent margins where the rate of spreading is different along different segments of the spreading ridge

Front 2

The cause of volcanism observed at Yellowstone national park is similar to that of

Back 2

the Hawaiian Islands

Front 3

a shield volcano has a lower slope angle than a strato (comosite) volcano because

Back 3

its basaltic lava flows have lower viscosities than the andesitic flows of strato volcanoes

Front 4

what is the significance of the change in direction of the Hawaiian Island chain and the Emperor Seamount Chain?

Back 4

the tectonic plate on which both island chains sit changed directions

Front 5

which tectonic margin would tend to have deep and shallow focused earthquakes?

Back 5

convergent

Front 6

Basaltic composition magma can form

Back 6

at sea floor spreading zones
at continental rift zones
above hotspots
back arc spreading basins

Front 7

S-waves____as tehy travel through the outer core

Back 7

are absorbed

Front 8

What is the significance of OH in the muscovite crystal structure?

Back 8

it is water likely incorporated during the subduction process

Front 9

why does the topographic expression of the Hawaian Island become progressively lower from the Big Island to the island lying northwest?

Back 9

the ocean lithosphere is lighter over the hotspot and it floats higher

Front 10

arrange the compositional zones of the earth accordin got their respective density (densest to lightest)

Back 10

inner core, outer core, mantle, ocean crust, continental crust

Front 11

what kind of late margin is represented by the Andes Mountains

Back 11

convergent margin (ocean-continental subduction)

Front 12

meteorites are thought to be composed of

Back 12

materials that are similar in composition to those found in the solid earth

Front 13

Which zone of the earth is also described as the "low velocity zone"

Back 13

asthenosphere

Front 14

the melting temperature of______must be reached in order for the earth to become compositionally zone

Back 14

metallic Fe and Ni

Front 15

why will the Juan de Fuca spreading ridge eventually be subducted under the North American plate?

Back 15

the rate of sea floor spreading is less than the rate of subduction at the convergent margin

Front 16

Why are andesitic rocks usually porphyritic

Back 16

two staged cooling history for andesitic magmas

Front 17

diamond is harder than graphite because

Back 17

diamonds have covalent bonds between its constituent atoms while graphite has vanderwahl bonds

Front 18

the silicate tetrahedron (SiO4) has a net charge of

Back 18

-4

Front 19

how does the silicate tetrahedron (Si)4) achieve charge balance

Back 19

it will share electrons between oxygen atoms
it will form ionic bonds with available cations
it will form metallic bonds with available cations

Front 20

why do the terrestrial planets have so little molecular (gaseous) hydrogen?

Back 20

the terrestrial planets are close to the suna nd the low density hydrogen was lost to space

Front 21

using the diagram and chemical formula shown below:
K2A14(Si6Al2O20)(OH,F)2

-how many oxygen atoms are being shared between the silicate tetrahedral muscovite sheets

Back 21

three

Front 22

K2A14(Si6Al2O20)(OH,F)2

-why does muscovite cleave between silicate sheets

Back 22

the bonds are stronger within the silicate sheets compared to between the silicate sheets

Front 23

math the magma type with the appropriate tectonic setting where it likely forms

1. cascade mountains
2. plutons under the Himilaya Mountains
3. Japan
a. basalt
b.granite
c.andesite
d.peridotite
e.andalucite

Back 23

-cascade mountains: andesite
-plutons under the Himalaya Mountains: granite
-Japan: andesite

Front 24

the aesthenosphere is composed of rock rich in

Back 24

peridotite (>90% olivine)

Front 25

as a granitic magma (wet melt) rises toward the surface

Back 25

its melting temp will increase
it will tend to crystallize before it reaches the surface

Front 26

a partial melt of the asthenosphere will tend to rise toward the surface because

Back 26

the melt is less dense than the surrounding rock

Front 27

pillow basalts form

Back 27

when the basalt flow is erupted into the water

Front 28

when two ocean plates converge

Back 28

the older plate will be subducted

Front 29

the most widely accpepted explanation for the earth's magnetic field is

Back 29

movement of electrons in the molten iron of its outer core

Front 30

white kind of plate margin existed when the appalachian mountains formed during the Paleozoic Era

Back 30

collision margin (continenet-continent)

Front 31

what type of volcanic rock would incorporate lithic fragments during the eruption

Back 31

volcanic breccia

Front 32

why does quartz develop six cleavage plains?

Back 32

the mineral does not cleave

Front 33

what is the main source of the erupted lava?

Back 33

partial melt of the asthenosphere

Front 34

magmas are divided into three compositional ranges based mainly on___content

Back 34

silica content

Front 35

why is there a low velocity zone for seismic waves entering the asthenosphere?

Back 35

the asthenosphere is a partial melt and seismic wave decelrate as they enter the phase change

Front 36

in the geologic techniques lab each group completed a topographic cross sections of Yosemite Valley
What profile shape was indicative a a glaciated valley?

Back 36

U-shaped

Front 37

in the plate tectonics lab we observed that the magnetic polarity stripes south of Alaska were unidirectional
how could you explain the fact that half o the magnetic stripes were missing?

Back 37

the spreading ridge that created the stripes was subducted under Alaska

Front 38

in the minerals lab the main diagnostic criteria for identifying the metallic mineral metaite was

Back 38

its reddish brown streak

Front 39

in the igneous rock lab we observed two volcanic rocks at the front of the lab. they were collected from

Back 39

Hawaii and Mt. St. Helens

Front 40

We know from seismic wave data that the outer core is liquid and the inner core is solid yet the actual temp of the outer core is lower than the inner cores actual temp.
1. how can we best explain the fact that inner and outer cores are both composed of metallic iron and nickel?
2.what makes the asthenosphere unique relative to the lowermost lithosphere and the uppermost mesosphere (upper mantle)?

Back 40

1. the melting temp for iron nickel is lower than the geothermal gradient temp in the outer core
2. the asthenosphere is at the pressure melting temp for the upper mantle composition

Front 41

a phaeritic (plutonic) rock composed of 5% quartz, 55% plagioclase, 25% amphibole and 5% pyroxene would be classified as___

Back 41

granite

Front 42

a plutonic rock composed of predominantly clacium-rich plagioclase and pyroxene would be classified as

Back 42

gabbro

Front 43

granite contains____olivine

Back 43

0%

Front 44

magma is being erupted from a hotspot.
1 what type of magma is produced at this setting?
2. this type of tectonic setting can be found___?
3. what is the main source of the erupted lava?

Back 44

1. basalt
2. beneath ocean basins and continents
3. partial melt of the asthenosphere