Quiz 2 (Mineral Groups, Volcanoes, Igneous, Sedimentary, Metamorphic Rocks)

Question 1

Mineral

Answer 1

Inorganic naturally occurring solid with an ordered crystalline structure and defined chemical composition

Question 2

Most abundant elements in minerals

Answer 2

(O, Si, Al, Fe) Ca, Mg, Na, K

Question 3

Silicates (mineral group)

Answer 3

Most common mineral at Earth’s surface, links or chains of SiO4, igneous - form directly from cooling of magma or lava

Question 4

Evaporites (mineral group)

Answer 4

Precipitated by the evaporation of an aqueous solution, salts

Question 5

Sulfides (mineral group)

Answer 5

Precipitate out of hot hydrothermal vents, contains sulfide ion SiO2, source of many economical metals

Question 6

How to classify minerals

Answer 6

Luster, hardness, cleavage/ fracture, reacts with acid

Question 7

Luster

Answer 7

The way a mineral reflects light (metallic or nonmetallic)

Question 8

Hardness

Answer 8

Resistance to being scratched

Question 9

Cleavage

Answer 9

Minerals breaks on planar surfaces due to weaker bonds, number of cleavages depends on structure of element, cleavage planes will reflect light the same (same angle) across surface

Question 10

Fracture

Answer 10

If all bonds are the same strength, there will be no preferred orientation. Fractures will occur in an irregular manner, each surface reflects light independently

Question 11

Streak

Answer 11

More reliable than color, done by rubbing sample on streak plate, most useful in identifying metallic minerals

Question 12

Reaction with Acid

Answer 12

CaCo3 is bonded ionically, so when acid is added the Ca and Co disassociate.

Question 13

Striations

Answer 13

Parallel lines on cleavage surface, useful when distinguishing plagioclase from potassium feldspar (no striations)

Question 14

Extrusive

Answer 14

Cooled on the surface, fast cooling, fine-grained

Question 15

Intrusive

Answer 15

Cooled in the crust, slow cooling, coarse-grained

Question 16

Texture

Answer 16

Size, shape and arrangement of grains

Question 17

Pegmatite

Answer 17

Very coarse-grained rock, formed when magma cools very slowly at depth

Question 18

Glassy texture

Answer 18

No crystals, cooled very quickly

Question 19

Porphyritic

Answer 19

Two crystal sizes

Question 20

Frothy texture

Answer 20

Bubble chambers (vesicles)

Question 21

Pyroclastic texture

Answer 21

Formed as a result of magma cooling in the air (volcanic ash, volcanic bombs)

Question 22

Mafic

Answer 22

Dark-colored, at divergent boundaries where there is increased heat flow and decompression melting

Question 23

Felsic

Answer 23

Light-colored, at convergent boundaries where there is high pressure & high temps & water release melting occurs above subduction zones

Question 24

Intermediate

Answer 24

Between light and dark, at convergent boundaries

Question 25

Intraplate volcanism (hot spots)

Answer 25

Produced by rising mantle plumes, oceanic hot spots = mafic rocks, continental hot spots = felsic rocks

Question 26

Igneous rock

Answer 26

Rock that forms when hot molten rock (magma or lava) cools and becomes solid

Question 27

Magma

Answer 27

Hot molten rock beneath Earth's surface which includes suspended minerals and dissolved gases

Question 28

Lava

Answer 28

Magma exposed at Earth's surface

Question 29

Phaneretic

Answer 29

Igneous rock texture, can be seen with naked eye, intrusive

Question 30

Aphanitic

Answer 30

Igneous rock texture, crystals are too small to see or rock is glass, extrusive

Question 31

Porphyritic

Answer 31

Igneous rock texture, large crystals in fine-grained matrix, two (or more) stage cooling history

Question 32

Pegmatitic

Answer 32

Crystals larger than 2 cm on average, intrusive but rare

Question 33

Mineral forms

Answer 33

Single, chains, double chains, sheets, 3D

Question 34

Extrusive equivalent to granite

Answer 34

rhyolite

Question 35

Extrusive equivalent to granodiorite

Answer 35

dacite

Question 36

Extrusive equivalent to diorite

Answer 36

andesite

Question 37

Extrusive equivalent to gabbro

Answer 37

basalt

Question 38

Where rock melts

Answer 38

Mantle plume and hot spot volcano, subduction zone (yields volcanic arc), beneath a mid-ocean ridge

Question 39

Dykes (magmatic intrusion)

Answer 39

Vertical sheets

Question 40

Sills (magmatic intrusion)

Answer 40

Horizontal sheets

Question 41

Necks (magmatic intrusion)

Answer 41

Near-vertical conduits

Question 42

Laccoliths (magmatic intrusion)

Answer 42

Wart-like bumps

Question 43

Plutons & batholiths (magmatic intrusion)

Answer 43

Huge bodies

Question 44

Shield volcano

Answer 44

Low sloping, usually basaltic, nonexplosive

Question 45

Strato volanco

Answer 45

Mixed rock and tephra, steep-sided, explosive

Question 46

Tephra

Answer 46

Unconsolidated accumulations of pyroclastic grains (pieces of rock blown from volcano during eruption)

Question 47

Pieces of rock blown from a volcano during eruption

Answer 47

Ash, lapilli (marble size), bombs (large)

Question 48

Tuff

Answer 48

Rock consisting of welded pyroclastic material (pieces are bound together)

Question 49

Clastic sediments

Answer 49

Broken pieces, clay to boulder size

Question 50

Chemical

Answer 50

Precipitated from water

Question 51

Biogenic

Answer 51

Shells and casts of organisms

Question 52

2 settings that result in large sedimentary basins

Answer 52

Subduction zones, continental rift zones

Question 53

Graded bedding

Answer 53

Coarse up to fine sediment, deposition from water

Question 54

Cross bedding

Answer 54

Bedding planes not parallel to stratification, deposition from moving water or air

Question 55

Lithification

Answer 55

Compaction from deposition and burial, reduction in porosity, cementation

Question 56

Classification of clastics (biggest to smallest)

Answer 56

Gravel, sand, silt, clay

Question 57

Metamorphism

Answer 57

The process of changing the characteristics of a rock by changes in pressure and temperature, alters mineral and texture but not composition and no melting