Chapter 03B: Rocks

Question 1

Rocks

Answer 1

Aggregate of one or more minerals

Question 2

Rock types

Answer 2

Igneous

Sedimentary

Metamorphic

Question 3

Igneous rocks

Answer 3

Minerals with the highest melting point crystalize first

Made from magma and lava/extremely high heat and pressure

Question 4

Magma

Answer 4

Subsurface melted rock

Question 5

Lava

Answer 5

Surface melted rock

Question 6

Intrusive

Answer 6

Forming of a rock below the surface

Associated with slow cooling and coarse grain, crystals

Question 7

Extrusive

Answer 7

Forming of rock above the surface

Associated with rapid cooling and fine grain, lack of visible crystals

Question 8

Aphanitic

Answer 8

Fine-grained texture of igneous rocks formed extrusively (rapid cooling)

Question 9

Phaneritic

Answer 9

Coarse-grained texture of igneous rocks formed intrusively (slow cooling)

Question 10

Porphyritic

Answer 10

Coarse-grained texture within a fine-grained matrix of igneous rocks formed both intrusively and extrusively (slow and rapid cooling)

Question 11

Vesicular

Answer 11

Igneous rocks with cavities (vesicles) formed from escaping gas bubbles formed extrusively (rapid cooling)

Question 12

Glassy

Answer 12

Very fine-grained texture of igneous rocks formed extrusively (very rapid cooling) – few or no crystals (microscopic)

Question 13

Pegmatitic

Answer 13

Very coarse-grained texture of igneous rocks formed intrusively (very slow cooling)

Question 14

Pyroclastic (fragmental)

Answer 14

Igneous rocks formed from compaction of volcanic ash and explosive debris.

Question 15

Mafic

Answer 15

Igneous rock color with mostly dark colored minerals

Question 16

Intermediate

Answer 16

Igneous rock with mixture of light and dark minerals

Question 17

Felsic

Answer 17

Igneous rock with mostly light colored minerals

Question 18

Sedimentary rocks

Answer 18

Rocks formed from pre-existing rocks that were weathered and eroded down to sediments, transported, deposited, and lithified into sedimentary rocks

Often contain void spaces that hold/transport water and petroleum

Raw materials for glass, concrete, sheetrock

Question 19

Physical weathering

Answer 19

The breaking apart of rocks without changing their chemica composition

E.g. frost wedging, plant roots

Question 20

Chemical weathering

Answer 20

Breaking down of rocks by chemical means and changing its chemical composition

E.g. dissolution, hydrolysis, redox

Question 21

Lithification

Answer 21

The compaction and cementation of sediment

Question 22

Detrital/Clastic rocks

Answer 22

Sedimentary rocks formed from mechanical weathering debris.

Question 23

Chemical rocks

Answer 23

Sedimentary rocks that are made chemically or biochemically, i.e. through a means like dissolution or excretion (by organisms)

E.g. limestone, rock salt

Question 24

Metamorphic rocks

Answer 24

Rocks created from pre-existing rocks that are altered with heat and pressure, but no melting

Question 25

Contact metamorphism

Answer 25

Heat, low pressure

Nonfoliated texture (eg. marble, quartzite)

Question 26

Regional metamorphism

Answer 26

Heat, high pressure

Foliated texture (e.g. slate, gneiss)

Question 27

Cementation glues (sedimentary rocks) (3)

Answer 27

Silica

Iron oxide

Calcite