Lecture 3

Question 1

Graphite and diamonds result of

Answer 1

different bonding

Question 2

Mineral pairs most abundant in

Answer 2

basalt pyroxene and p

Question 3

Fast cooling magma produces

Answer 3

aphanitic texture

Question 4

Phenocrysts in a porphytic texture reflects

Answer 4

slow cooling

Question 5

Basalts are the most common

Answer 5

EXTRUSIVE rocks on earth

Question 6

Glassy texture are the product

Answer 6

lower nucleation and lower growth rates than apaphanitic texture

Question 7

Pahoehoe

Answer 7

ropy lava

Question 8

Pillow lava

Answer 8

Formed in aqueous environment

Question 9

Main gases

Answer 9

H2o so2 co2

Question 10

How do volcanoes explode?

Answer 10

Gasses= volitaile
Gas is trapped under pressure in magma chamber
conduit is plugged
when conduit released pressure explodes

Question 11

Volcanic gas

Answer 11

Gas bubbles trapped in cooled volcanic rock.
Gas bubbles called vesicles.
The way the gas escapes determines what kind of eruption

Question 12

low-viscosity basalt

Answer 12

Easier for gas to escape smaller eruption

Question 13

high-viscosity rhyolite

Answer 13

Hard for gas to escape =big eruption

Question 14

Fumaroles

Answer 14

vents or openings at the surface where volcanic gases and vapors are emitted.

Question 15

Pyroclastic material

Answer 15

Pyro = fire and clastic = fragment

Question 16

Bombs

Answer 16

> 64mm
Aerodynamic ribbon
solidifying globs of lava as it travels through the air

Question 17

Lapilli

Answer 17

Dark basaltic
called cinder
2-64mm

Question 18

Ash

Answer 18

<2mm
fine

Question 19

block

Answer 19

Exactly what it sounds like

Question 20

cinder cone

Answer 20

Smallest type of volcano
cone-shaped piles of ejected lapilli-sized
fragments
built up around vent
symetrical
deep crater

Question 21

Weathering/erosion

Answer 21

Active=smooth cone
Erosion=gullies
Eventually= hills of volcanic rock

Question 22

Size of volcano

Answer 22

• volume of eruption vs. erosion
  Age/rate

Question 23

basalt

Answer 23

Fine-grained = aphanitic (super fine minerals)= rapid cooling

Question 24

How do we describe (and classify/name) a rock?

Answer 24

Mineralogy: type of minerals
texture: grain/crystal size
variability

Question 25

petrography

Answer 25

the study of rocks in thin sections by means of a petrologic microscope

Question 26

Glass

Answer 26

no mineral
very fast cooling

Question 27

Graph

Answer 27

slide 25

Question 28

Porphyritic texture

Answer 28

an igneous rock texture in which large crystals are set in a finer-grained or glassy groundmass.

Question 29

important elements

Answer 29

si, Al, Fe, Mg, Ca, Na, O

Question 30

Mineral

Answer 30

Minerals have a specialized
geologic definition. They are
naturally occurring, (mostly)
inorganic crystalline solids
formed by geologic processes
and with a definite chemical
composition.

Question 31

Chemical bonding and mineral formation

Answer 31

atomic packing and the nature of chemical bonding determine the mineral properties

Question 32

Crystal structure: polymorphs ( different crystal forms of the same compound)

Answer 32

ex.
Diamond and graphite are
polymorphs of carbon

Question 33

Silica tetrahedron

Answer 33

• The SiO44− anionic unit is also known as the silica tetrahedron, a fundamental
  building block of silicate minerals.
• The silica tetrahedra can be depicted in several ways: as an atomic diagram, a
  ball model, a ball and stick model, or as a geometric sketch.

Question 34

Pyroxene, Diopside:

Answer 34

CaMgSi2O6

Question 35

Olivine

Answer 35

(Mg,Fe)2SiO4
Forsterite: Mg2SiO4
Fayalite: Fe2SiO4

Question 36

Plagioclase feldspar

Answer 36

(Ca,Na)Al1-2Si2-3O

Question 37

Albite

Answer 37

NaAlSi3O8

Question 38

Anorthite

Answer 38

CaAl2Si2O8

Question 39

Quartz

Answer 39

SiO2