Rocks Materials of the Solid Earth

Question 1

The rock cycle is a good model for thinking about the transformation of one rock to another due to Earth processes. . Given the right conditions, any kind of rock can be transformed into any other kind of rock.

Answer 1

Rock Cycle

Question 2

form when hot, molten rock crystallizes and solidifies

Answer 2

Igneous rocks

Question 3

Completely or partly molten rock that is below Earth’s surface. It consists of a liquid
melt that contains gases (volatiles) such as water vapor, and it may contain solids (mineral crystals).

Answer 3

Magma

Question 4

Completely or partly molten rock that is on the Earth’s surface

Answer 4

Lava

Question 5

Molten rock cools and solidifies

Answer 5

Crystallization

Question 6

When molten rock solidifies at the surface

Answer 6

Extrusive or Volcanic rock

Question 7

Most magma loses its mobility before reaching Earth’s surface and eventually crystallizes deep below the surface.Igneous rocks that form at depth

Answer 7

Intrusive or Plutonic rock

Question 8

If the molten material is cooled almost instantly, there is insufficient time for the ions to arrange themselves into a crystalline network. Solids produced in this manner consist of randomly distributed atoms.

Answer 8

Glass

Question 9

Instant quenching sometimes occurs during violent volcanic eruptions that produce tiny shards of glass

Answer 9

Volcanic ash

Question 10

Igneous rocks in which is composed almost entirely of light colored silicates such as quartz and potassium feldspar and contain about 10 percent dark silicate minerals

Answer 10

Granitic or Felsic

Question 11

Rocks that contain at least 45 percent dark silicate minerals and calcium-rich plagioclase feldspar (but no quartz)

Answer 11

Basaltic or mafic

Question 12

rocks with a composition between granitic and basaltic rocks and contain at least 25 percent dark silicate minerals, mainly amphibole, pyroxene, and biotite mica, with the other dominant mineral being plagioclase feldspar.

Answer 12

Andesitic or intermediate

Question 13

Igneous rocks that has very low silica content and composed mostly of olivine minerals.

Answer 13

Ultramafic

Question 14

the overall appearance of a rock, based on the size, shape, and arrangement of its mineral grains

Answer 14

Texture

Question 15

Igneous rocks that form at Earth’s surface or as small intrusive masses within the upper crust, where cooling is relatively rapid. The crystals that make up fine-grained igneous rocks are so small which can be distinguished only with the aid of a polarizing microscope or other sophisticated techniques

Answer 15

Fine-grained texture

Question 16

When large masses of magma slowly crystallize at great depth. Consist of a mass of intergrown crystals that are roughly equal in size and large enough so that the individual minerals can be identified without the aid of a microscope

Answer 16

Coarse-grained texture

Question 17

developed when magma that has been slowly cooling and crystallising within the Earth’s crust is suddenly erupted at the surface, causing the remaining uncrystallised magma to cool rapidly.

Answer 17

Porphyritic texture

Question 18

The large crystals in porphyritic rocks

Answer 18

Phenocryst

Question 19

The matrix of smaller crystals wherein larger crystals are embedded.

Answer 19

Groundmass

Question 20

Igneous rocks that have voids left by gas bubbles that escape as lava solidifies.

Answer 20

Vesicular texture

Question 21

Nearly spherical openings as lava solidifies

Answer 21

Vesicles

Question 22

Molten rock that is is quenched and cools quickly to become a solid.

Answer 22

Glassy texture

Question 23

Formed from the consolidation of individual rock fragments ejected during explosive volcanic eruptions.

Answer 23

Pyroclastic (fragmental) texture

Question 24

As magma cools, certain minerals crystallize first at relatively high temperatures. At successively lower temperatures, other minerals begin to crystallize.

Answer 24

Vowen’s reaction series

Question 25

Occurs when the earlier formed minerals are more dense (heavier) than the liquid portion and sink toward the bottom of the magma chamber

Answer 25

Crystal settling

Question 26

The formation of one or more secondary magmas from a single-parent magma

Answer 26

Magma settling

Question 27

Created by accumulating existing rocks or fragments of extinct organisms on the Earth’s surface. These are compacted and cemented sediments

Answer 27

Sedimentary rock

Question 28

indicates the nature of these rocks, for it is derived from the Latin sedimentum, which means “settling,” a reference to a solid material settling out of a fluid.

Answer 28

Sedimentary

Question 29

Rocks are created from weathered and eroded fragments of pre-existing rock. These eroded pieces are transported, deposited, compacted, and cemented into sedimentary rocks in a process known as lithification.

Answer 29

Detrital sedimentary rock

Question 30

sediments that originated as solid particles from weathered rocks

Answer 30

Detritus

Question 31

Coarse (over 2mm) and rounded gravel-sized particles

Answer 31

Conglomerate

Question 32

Coarse (over 2mm) and angular gravel-sized particles

Answer 32

Breccia

Question 33

Medium (1/16 to 2mm) and rocks that sand-sized particles prevail

Answer 33

Sandstone

Question 34

Medium (1/16 to 2mm) If abundant feldspar is present in the rock

Answer 34

Arkose

Question 35

Fine (1/16 to 1/256mm) and composed mostly of clay-sized sediments intermixed with slightly larger silt-sized grains (0.0625-0.0039)

Answer 35

Siltstone

Question 36

Very fine (less than 1/256mm) the most common sedimentary rock, is made of very fine-grained sediment and composed mainly of clay minerals

Answer 36

Shale/Mudstone

Question 37

Form by chemical precipitation that begins when water traveling through rock dissolves some of the minerals. These minerals are carried away from their source and eventually redeposited, or precipitated, when the water evaporates away.

Answer 37

Chemical sedimentary rock

Question 38

These rocks are formed from precipitation indirectly through life processes of water-dwelling organisms

Answer 38

Biochemical sedimentary rock

Question 39

an abundant sedimentary rock, is composed chiefly of the mineral calcite (CaCO3).

Answer 39

Limestone

Question 40

Starting at a microscopic scale, the calcium carbonate in the rock begins to crystallize or recrystallize into fine-grained calcite crystals. As the duration and intensity of metamorphism continues, the calcite crystals increase in size.

Answer 40

Crystalline limestone

Question 41

Rocks that have microcrystalline calcite

Answer 41

Microcrystalline Limestone

Question 42

A form of limestone deposited by mineral rich springs, especially hot springs, or caves. Travertine often has a fibrous or concentric banded appearance.

Answer 42

Travertine

Question 43

a coarse rock composed of loosely cemented shells and shell fragments

Answer 43

Coquina

Question 44

Rocks that have visible fossils in crystalline matrix

Answer 44

Fossiliferous Limestone

Question 45

a soft, porous rock made up almost entirely of the hard parts of microscopic organisms that are no larger than the head of a pin.

Answer 45

Chalk

Question 46

A sedimentary rock composed of microcrystalline or cryptocrystalline quartz

Answer 46

Chert

Question 47

A chemical sedimentary rock and an example of an evaporite. Evaporation causes minerals (gypsum) to precipitate from water

Answer 47

Rock gypsum

Question 48

A chemical sedimentary rock and an example of an evaporite. Evaporation causes minerals (salt) to precipitate from water

Answer 48

Rock salt

Question 49

organic sedimentary rock that forms from the accumulation and preservation of plant materials, usually in a swamp environment. It is formed when a sub bituminous coal is subjected to increased levels of organic metamorphism.

Answer 49

Bituminous coal

Question 50

Deposits that form from the precipitation of solid mineral crystals from a concentrated solution of salt- or freshwater, in other words, from brine

Answer 50

evaporite deposit

Question 51

As the water evaporates, dissolved materials left behind as a white crust on the ground

Answer 51

Salt flats

Question 52

Partially altered plant material and contains less than 40 to 55 percent carbon and lots of moisture

Answer 52

Peat

Question 53

Soft brown coal and 40 to 55 per cent carbon. Intermediate stage and moisture content is high (over 35 per cent)

Answer 53

Lignite

Question 54

Soft black coal and 40 to 80 per cent carbon

Answer 54

Bituminous

Question 55

Hard black coal and 80 to 95 per cent carbon

Answer 55

Anthracite

Question 56

refers to the processes by which sediments are transformed into solid sedimentary rocks.

Answer 56

Lithification

Question 57

As sediments accumulate through time, the weight of overlying material compresses the deeper sediments.

Answer 57

Compaction

Question 58

The cementing materials are carried in a water-rich solution that percolates through the pore spaces between particles. Over time, the cement precipitates onto the sediment grains, fills the open spaces, and acts like a “glue” to join the particles together.

Answer 58

Cementation

Question 59

the horizontal layers, or beds, present in most sedimentary rocks, that has certain lithologic properties

Answer 59

Strata (beds)

Question 60

a surface that separates each layer from those above or below it.

Answer 60

Bedding planes

Question 61

the traces or remains of prehistoric life

Answer 61

fossils

Question 62

form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.

Answer 62

Metamorphic rock

Question 63

which means “to change form,” is a process that leads to changes in the mineralogy, texture (for example, grain size), and sometimes chemical composition of rocks.

Answer 63

Metamorhism

Question 64

agents of metamorphism include heat, confining pressure, differential stress, and chemically active fluids.

Answer 64

Agents of metamorphism

Question 65

Thermal energy (heat) is the most important factor driving metamorphism. It triggers chemical reactions that result in the recrystallization of existing minerals and the formation of new minerals. Heat sources are from nearby magma or rocks that are subjected at higher depths which has higher temperature

Answer 65

Heat

Question 66

Pressure applied equally on all surfaces of a body and causes the spaces between mineral grains to close, producing a more compact rock that has greater density

Answer 66

Confining pressure

Question 67

If stress is not equal from all directions and stresses are greater in one direction than in others

Answer 67

Differential stress

Question 68

Fluids that surround mineral grains act as catalysts to promote recrystallization by enhancing ion migration. Chemically active fluids can produce two types of metamorphism, explained below. The first type changes the arrangement and shape of mineral grains within a rock; the second type changes the rock’s chemical composition

Answer 68

Chemically active fluids

Question 69

metamorphism takes place at low temperatures and relatively low pressure.

Answer 69

Low-grade metamorphism

Question 70

metamorphism takes place at high temperatures and relatively high pressure.

Answer 70

High-grade metamorphism

Question 71

Rocks experience a rise in temperature when they are intruded by magma rising from below.

Answer 71

Contact (thermal) metamorphism

Question 72

a type of metamorphism where rock minerals and texture are changed by heat and pressure over a wide area or region.

Answer 72

Regional metamorphism

Question 73

the range of metamorphic change a rock undergoes, progressing from low (little metamorphic change) grade to high (significant metamorphic change) grade

Answer 73

Degree of metamorphism

Question 74

refers to any nearly flat arrangement of mineral grains or structural features within a rock.

Answer 74

Foliation

Question 75

Rocks that do not display foliation texture and typically develop in environments where deformation is minimal and the parent rocks are composedof minerals that have a relatively simple chemical composition

Answer 75

Non-foliated

Question 76

a very fine-grained foliated rock composed of minute mica flakes that are too small to be visible and has an excellent rock cleavage, or tendency to break into flat slabs.

Answer 76

Slate

Question 77

Its constituent platy minerals, mainly muscovite and chlorite, are larger than those in slate but not large enough to be readily identifiable with the unaided eye. It displays glossy sheen and wavy surface.

Answer 77

Phyllite

Question 78

are moderately to strongly foliated rocks formed by regional metamorphism. They are platy and can be readily split into thin flakes or slabs.

Answer 78

Schist

Question 79

the term applied to banded metamorphic rocks in which elongated and granular minerals predominate and exhibit strong segregation of light and dark silicates, giving them a characteristic banded texture.

Answer 79

Gneiss

Question 80

a coarse, crystalline rock whose parent rock is limestone. Composed of large interlocking calcite crystals, which form from the recrystallization of smaller grains in the parent rock.

Answer 80

Marble

Question 81

a very hard metamorphic rock most often formed from quartz sandstone. Under moderate- to high-grade metamorphism, the quartz grains in sandstone fuse.

Answer 81

Quartzite

Question 82

A rock granitic in composition and consist of large crystals of quartz, feldspar, and muscovite.

Answer 82

Pegmatite

Question 83

a type of mineral deposit that consist of a localized zone of fracture-filling minerals. They typically form within fractures or fissures in rock and are often found in or near fault zones, where rocks have been fractured and deformed.

Answer 83

Vein deposit

Question 84

ores are distributed as minute masses throughout the entire rock mass

Answer 84

Disseminated deposit

Question 85

General term for any hydrocarbon that may be used as a fuel, including coal, oil, natural gas, bitumen from tar sands, and shale oil.

Answer 85

Fossil fuel

Question 86

a type of fossil fuel, formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years

Answer 86

coal

Question 87

generated from the remains of marine plants and animals, mainly microscopic plankton, which died in ancient seas millions of years ago. With increased temperature and burial, chemical reactions gradually transform this organic matter into the liquid and gaseous hydrocarbons

Answer 87

OIl and Natural gas

Question 88

are commonly shales and lime mudstones, which contain significant amount of organic matter. Any rock that has the capability to generate and expel enough hydrocarbons to form an accumulation of oil or gas

Answer 88

Source rock

Question 89

A geologic environment that allows for economically significant amounts of oil and gas to accumulate underground

Answer 89

Oil trap

Question 90

a porous, permeable layer of rock that will yield petroleum and natural gas in sufficient quantities

Answer 90

Reservoir rock

Question 91

virtually impermeable to oil and gas and halts the upwardly mobile oil and gas and keeps the oil and gas from escaping at the surface.

Answer 91

Cap rock

Question 92

an uparched series of sedimentary strata

Answer 92

Anticline

Question 93

This type of trap forms when strata are displaced in such a manner as to bring a dipping reservoir rock into position opposite an impermeable bed. The upward migration of the oil and gas is halted where it encounters the fault.

Answer 93

Fault trap

Question 94

Such areas have thick accumulations of sedimentary strata, including layers of rock salt. Because oil and gas migrate to the highest level possible, they accumulate in the upturned sandstone beds adjacent to the salt column

Answer 94

Salt dome

Question 95

These oil-bearing structures result primarily from the original pattern of sedimentation rather than structural deformation.

Answer 95

Stratigraphic (pinchout) trap

Question 96

the process of injecting water, sand, and/or chemicals into a well to break up underground bedrock to free up oil or gas reserves.

Answer 96

Hydraulic fracturing