Earth Science Exam 3

Front 1

Criteria to be a mineral

Back 1

-Naturally occurring

-Inorganic

-Solid

-Known and fixed chemical composition

-Known and fixed crystalline structure

Front 2

Color

Back 2

-A mineral property

-How a mineral appears in light

-Caution: Some minerals naturally come in a variety of colors & processes alter the original color

Front 3

Streak

Back 3

-A mineral property

-Scratching a mineral on a streak plate

-Useful for relatively soft minerals only

Front 4

Luster

Back 4

-A mineral property

-How a mineral reflects light

-Metallic vs. Non-metallic

Front 5

Hardness

Back 5

-Resistence to abraison

-Mohs scale of hardness

1. Talc

2. Gypsum

3. Calcite

4. Flourite

5. Apatite

6. Orthoclase feldspar

7. Quartz

8. Topaz

9. Corundum

10. Diamond

Front 6

Crystal form

Back 6

-A mineral property

-Preferred growth shape of particular minerals

Front 7

Fracture and cleavage

Back 7

-A mineral property

-How minerals break under applied stress

Front 8

Fracture

Back 8

-Mineral breaks along irregular or curved surfaces

-Conchoidal fracture: Breakage along curved surfaces

-Non-conchoidal fracture: breakage along irregular surfaces

Front 9

Cleavage

Back 9

-Mineral breaks along smooth, parallel planes

-1 direction (basal cleavage)

-2 directions (prismatic cleavage)

-3 directions at 90° from each other (cubic cleavage)

-3 directions not at 90° from each other (rhombohedral cleavage)

-4 directions (octahedral cleavage)

Front 10

Other properties associated with minerals

Back 10

-Specific gravity

-Odor

-Taste

-Reaction to acid

-Magnetism

Front 11

Silicate minerals

Back 11

-Form from cooling and crystallization of molten rock

-Contain silicon (Si) bonded to oxygen (O)

-Quartz is the simplest one

-Some contain silicon-oxygen tetrahedrons

Front 12

Silicon-oxygen tetrahedron

Back 12

-Fundamental building block of silicate minerals (besides quartz)

-1 Si ion surrounded by 4 O ions to form a 3 sided pyramid

Front 13

Non-silicate minerals

Back 13

-Don't contain silicon

-Numerous classes

-Native elements: composed of single element found in nature

-Sulfides: contain sulfide (S)

-Oxides: contain oxide (O) ion

-Carbinates: contain carbonate (CO3) ion

Front 14

Rocks

Back 14

-Aggregations of minerals

-May be composed of multiple minerals or multiple crystals of a single mineral

-Three types: igneous, sedimentary, and metamorphic

Front 15

Igneous rocks

Back 15

-Formed through cooling, and solidification of molten rock

-May also form through accumulation of material produced by volcanic activity

-Two types: intrusive and extrusive

Front 16

Intrusive

Back 16

-Magma solidifies and/or interacts with Earth materials relative deep underground

-Slower cooling = larger crystals

Front 17

Extrusive

Back 17

-Magma solidifies and/or interacts with other Earth materials at or near the surface

-Faster cooling = smaller crystals

Front 18

Igneous rock textures

Back 18

-Phaneritic: coarse-grained texture, associated with intrusive rocks, big crystals

-Aphanitic: fine-grained texture, small crystals, associated with extrusive rocks

Front 19

Igneous rock compositions

Back 19

-Definied by the amount of silica present

-Mafic magma: low silicon, dark in quartz, lacking quartz

-Felsic magma: high silicon, light in color, abundant quartz

-Intermediate magma

Front 20

Phaneritic, mafic rock

Back 20

Gabbro

Large crystals, intrusive, dark in color

Front 21

Phaneritic, felsic rock

Back 21

Granite

Large crystals, light in color, intrusive

Front 22

Aphanitic, mafic rock

Back 22

Basalt

Small crystals, extrusive, dark in color

Front 23

Aphanitic, felsic rock

Back 23

Rhyolite

Small crystals, extrusive, light in color

Front 24

Sedimentary rocks

Back 24

-Formed through cementation of loose, pre-existing solid particles (sediment)

-Four primary types: Volcanogenic, organic, chemical, clastic

Front 25

Volcanogenic sedimentary rocks

Back 25

-Produced by volcanic activity

-Can be considered an overlap with igneous rocks

-Tuff, pumice, and bentonite

Front 26

Organic sedimentary rocks

Back 26

-Composed of carbon-based particles produced directly by biological processes

-Accumulations of non-mineralized biological matter

-Coal: produced by consolidation of plant matter

Front 27

Chemical sedimentary rocks

Back 27

-Produced by low temperature and pressure chemical reactions

-Two types: carbonate and evaporite

Front 28

Carbonate rocks

Back 28

-Tyos of chemical sedimentary rock

-Composed of carbonate-based particles

-Will react with acid

-Ex. Limestone

Front 29

Evaporite rocks

Back 29

-Type of chemical sedimentary rock

-Composed of salts produced by evaporation

-Ex. Rock salt: composed of halite

-Ex. Rock gypsum: composed of gypsum

Front 30

Clastic sedimentary rocks

Back 30

-Produced by breakdown of pre-existing rocks into loose particles

-"Typical" sedimentary rocks

Front 31

Making a clastic rock

Back 31

1. Weathering

2. Erosion

3. Deposition

4. Lithification

Front 32

Weathering

Back 32

-Responsible for production of clastic sediments

-Processes that change the physical or chemical character of rocks at or near the surface

-Breakdown of pre-existing rocks into smaller pieces without transporting those pieces

-Two types: mechanical & chemical

Front 33

Mechanical weathering

Back 33

-Physical disintegration of rock into smaller pieces

-Does not affect composition of pre-existing rock

-Ex. Granite mountain broken up into granite blocks.. they are still granite

-Exposes rocks to more weathering by increasing surface area

Front 34

Mechanical weathering

Back 34

-Physical disintegration of rock into smaller pieces

-Does not affect composition of pre-existing rock

-Ex. Granite mountain broken up into granite blocks.. they are still granite

-Exposes rocks to more weathering by increasing surface area

Front 35

Frost wedging

Back 35

-Water seeps into a crack in a rock, then freezes, resulting in expansion and fracturing of rock

Front 36

Root wedging

Back 36

-Plant roots force their way into rocks and split them apart

Front 37

Pressure release

Back 37

-Intrusive igneous bodies expand and crack when exposed to the low pressure of the surface

Front 38

Thermal expansion

Back 38

-Exteriors of rocks are heated more than interiors, so differential expansion occurs and produces fractures

Front 39

Chemical weathering

Back 39

-Breakdown of rocks via chemical interactions

-Changes composition of pre-existing material; new products are formed

Front 40

Oxidation

Back 40

-Iron in rocks reacts with oxygen in water or atmosphere to produce iron-oxides

-"Rusting" of rocks

-Produces new minerals; weakens origin rock

Front 41

Dissolution

Back 41

-Acids dissolve away some minerals

-Fizzing of carbonate rocks

Front 42

Partial solution

Back 42

-Chemically complex minerals are altered to a residue of clays

Front 43

Erosion

Back 43

-Transportation of particles away from site of weathering and to site of accumulation

-High weather = low erosion

-Agents of erosion: water and wind, gravity, biological activity, glaciers

Front 44

Deposition

Back 44

-Sediments are transported to a place where they can accumulate and become buried (depositional environment)

Front 45

Lithification

Back 45

-Conversion of unconsolidated sediments into hard, sedimentary rock

-Two steps:

First, buried sediments are compacted

Second, spaces between grains are filled with chemically precipitated cement

Front 46

Gravel

Back 46

-Coarsest clastic sediment (larger than 2mm)

-Conglomerate: rock made of gravel-sized sediment with rounded edges

-Breccia: rock made of gravel-sized sediment with angular edges

Front 47

Sand

Back 47

-Intermediate clastic sediment (1/16 to 2mm)

-Sandstone: over generalized term for rock made of sand-sized sediment

Front 48

Mud

Back 48

-Fine clastic sediment (smaller than 1/16mm)

-Silt: 1/256-1/16mm

-Clay: smaller than 1/256mm

Front 49

Mudrocks

Back 49

-General term for rocks made of mud-sized sediment

-Three kinds: siltstone, shale, and mudstone

Front 50

Siltstone

Back 50

-Type of mudrock

-At least 2/3 silt

-Fine-grained, but gritty; faintly visible grains

Front 51

Shale

Back 51

-Type of mudrock

-Clay-dominated and laminated

-No visible grains, smooth to the touch

Front 52

Mudstone

Back 52

-Type of mudrock

-Clay-dominated and not laminated

-No visible grains; smooth to the touch

Front 53

Metamorphic rocks

Back 53

-Form through alteration of pre-existing rocks at high pressures and temperatures, but without melting them

Front 54

Metamorphism

Back 54

-Changes to rock texture and mineral composition occur

-Textural changes affect the size, shape, and arrangement of mineral crystals

-Compisitional changes affect the specific minerals present in a metamorphic rock

Front 55

Protolith

Back 55

-The parent rock

-Changes occur to the protolith to result in metamorphic rocks

Front 56

Primary controls of metamorphism

Back 56

-Composition of protolith

-Presence of fluids

-Temperature

-Pressure

Front 57

Composition of protolith

Back 57

-Control of metamorphism

-Elements in the parent rock are the "raw ingredients" for minerals in the metamorphic rock

Front 58

Presence of fluids

Back 58

-Control of metamorphism

-Fluids help facilitate chemical interactions and move ions around

Front 59

Temperature

Back 59

-Control of metamorphism

-Certain reactions and changes occur once a specific temperature is reached

Front 60

Pressure

Back 60

-Control of metamorphism

-Minerals precipitated under high pressure are smaller and denser than low pressure minerals in the parents rock

Front 61

Differential stress

Back 61

-Pressure applied to rocks more strongly in one direction than others

Front 62

Foliation

Back 62

-Layered (planar) texture in metamorphic rocks formed by alignment of platy or needle-shaped minerals that crystallized within a rock subjected to differential stress

-Shows direction of differential stress

Front 63

Marble

Back 63

-Non-foliated metamorphic rock

-Coarse-grained rock composed of interlocking crystals of calcite

-Metamorphosed limestone

-Will react with acid

Front 64

Quartzite

Back 64

-Non-foliated metamorphic rock

-Quartz grains welded together to produce a fine-grained, physically strong rock

-Metamorphosed quartz sandstone

Front 65

Slate

Back 65

-Foliated metamorphic rock

-Lowest metamorphism

-Very fine-grained rock that splits into thin, flat, parallel layers

-Earth, non shiny surfaces

-Only from mudrock protoliths

Front 66

Phyllite

Back 66

-After slate, still low metamorphism

-Fine-grained rock that has shiny surfaces (a "sheen") due to microscopic mica formation

-Essentially only from mudrock protoliths

Front 67

Schist

Back 67

-After phyllite, much more metamorphism

-Coarse-grained rock with noticeably aligned platy and elongate minerals

-Relatively strong metamorphism

-Multiple protoliths can produce schists

-Variable in composition

Front 68

Gneiss

Back 68

-After schist, most extreme metamorphism

-Coarse-grained rock with distinct light and dark banding resulting from segregation of minerals in to separate layers

-Multiple protoliths can produce gneisses