Earth Materials and the Cycle of Rock Transformation

Question 1

______ the outermost layer of the planet

Answer 1

earths crust

Question 2

Crust’s thickness ranges between

Answer 2

n 8 to 80 km and comprises the continents and ocean basin

Question 3

the thickness of the oceanic crust is generally

Answer 3

less than 10 k

Question 4

continental crust

Answer 4

averages about 40 km

Question 5

About 10 percent of the crust exceeds 50 km, with the greatest thickness reported in the ________, where it is about 80 km

Answer 5

Himalayas

Question 6

mineral definition

Answer 6

A mineralcan be defined as a naturally occurring, inorganic substance that has a definite chemical composition and a characteristic atomic structure. This gives each mineral its distinctive properties, such as colour, lustre, and hardness. Most minerals have a crystalline structure that reflects the internal arrangement of its composing atoms

Question 7

When minerals are combined they form

Answer 7

rock

Question 8

are solidified from mineral matter in a high temperature molten state. The mineral grains in igneous rocks are tightly interlocked, and the rock is normally very strong

Answer 8

igneous rock

Question 9

magma

Answer 9

cools and solidifies between about 600 and 1,200 °C, either below the surface as intrusive rocks, such as granite, or on the surface as extrusive rocks, such as volcanic lava

Question 10

Layered accumulations of mineral particles which are derived mostly by weathering and erosion of pre-existing rock lead to the formation of

Answer 10

sedimentery rock

Question 11

Diagenesis

Answer 11

reveals the various chemical, physical, and biological changes that occur as layers of sediment transform into rocks. The resulting rock layers are called strata.

Question 12

s are the most common exposed rock types and cover about 75 percent of the Earth’s surface. However, they account for only about 5 percent of the total mass of the Earth’s rocks because they are only found within a comparatively thin layer over igneous and metamorphic rock

Answer 12

sedimentery rocks

Question 13

Unlike igneous and metamorphic rocks, sedimentary rocks often contain______

Answer 13

fosils

Question 14

When igneous or sedimentary rocks are physically or chemically changed, due to the subsequent application of heat and pressure during episodes of significant crustal movement, they turn intto

Answer 14

metamorphic rocks

The process of metamorphismcreates new minerals and rock structures

Question 15

formation of igneou rock

Answer 15

Igneous rock crystallizes from hot, molten magma that originates deep below the surface of the Earth. The molten rock migrates upward from the magma chambers through fractures in older solid rock and eventually solidifies within (igneous intrusive rock; intrusion) or on top (extrusive igneous rock; lava) of the Earth’s crust

Question 16

The _________ and ______are the main determinants of rock composition and crystal size

Answer 16

chemical composition of the magma and the rate of cooling

Question 17

the _____________ that form igneous rocks are chemical compounds that contain silicon and oxygen atoms, combined with various proportions of other elements, particularly aluminum, iron, calcium, sodium, potassium, and magnesium

Answer 17

silicate minerals

Question 18

quartz

Answer 18

) is one of the most common minerals. It is quite hard and resists chemical breakdow

Question 19

silicate aluminim minerals

Answer 19

feldspars

Question 20

Quartz and feldspar form the ______mineral group

Answer 20

felsic

These minerals are light in colour (white, pink, or grayish) and lower in density than the other silicate minerals; they form at comparatively low temperatures.

Question 21

Other common silicate minerals include the biotite, amphibole, and pyroxene groups. All three contain aluminum, magnesium, iron, and potassium or calcium. These minerals are described as __________

Answer 21

mafic

(“ma” for magnesium; “f ” from the chemical symbol Fe for iron).

All of these mafic minerals are dark in colour(usually black) and are denser than the felsicminerals. The mafic minerals are characteristically found in rocks that solidify at high temperature

Question 22

Granite is one of the most common intrusive igneous rocks. Typical graniteconsists mainly of potassium feldspar, with lesser amounts of quartz and Na-plagioclase, and some mica and amphibole. Because most of the volume of granite is of felsicminerals, granite is classified as _________

Answer 22

felsic igneou rock

Question 23

rocks cool very slowly — over hundreds or thousands of years — and, as a result, develop large, readily seen crystals (granite and diorite are good examples of coarse-textured intrusive igneous rocks).

Answer 23

intruive rocks

Question 24

which cools rapidly, is fine-textured, and the individual crystals can only be seen through a microscope. Most lava solidifies as a dense, uniform rock with a dark, dull surface. Sometimes lava cools to form shiny obsidian or volcanic glass. If the lava contains dissolved gases, it may solidify to form scoria, a rock with a frothy, bubble-filled texture.

Answer 24

extrusive rocks

Question 25

body of intrusive igneous rock is called

Answer 25

pluton

Question 26

ranite typically accumulates in enormous plutons, called

Answer 26

batholiths

Question 27

chemical weathering

Answer 27

Once exposed, igneous rock minerals may also be altered by water and dissolved gase

Question 28

mechanical weathering

Answer 28

Weathering also includes physical forces, like frost action, that break up rock into small fragments and separate the component minerals, grain by grain. Rock fragmentation caused in this way is termed mechanical weathering (accelerates mineral alteration because it greatly increases the surface area that is exposed to chemically active solutions)

Question 29

n the process of mineral alteration, solid rock is weakened, softened, and fragmented, yielding particles of many sizes and mineral compositions. When transported by a fluid medium, such as water or air, these particles are known collectively a

Answer 29

sediment

Question 30

e three major types of sedimentary material

Answer 30

the first type is clastic sediment, which consists of inorganic rock and mineral fragments called clasts. The second type is chemically precipitated sediment, which consists of inorganic mineral compounds precipitated from a chemical solution. The third class is organic sediment, which consists of the tissues of plants and animals, accumulated and preserved after death.

Question 31

coal

Answer 31

is the end result of this process, with individual coal seams interbedded with shale, sandstone, and limestone strata.

Question 32

oil deposits and natural gas

Answer 32

f organic origin, but they are classed as mineral fuels rather than minerals. Oil and gas deposits commonly occupy open, interconnected pores in a thick sedimentary rock layer, such as a porous sandstone

Question 33

Igneous or sedimentary rock may be altered by the tremendous pressures and high temperatures that accompany crustal deformation processes, such as the creation of mountain ranges. The result is rock so changed in texture and structure that it is reclassified a

Answer 33

metamorphic

Question 34

Igneous, sedimentary, and metamorphic rocks are transformed from one to another in a continuous cycle over the course of many millions of years. Igneous rock forms when pre-existing rock of any class melts and this magma subsequently cools and solidifies. Through weathering and erosion, pre-existing rock breaks down and the fragments accumulate in layers that eventually become compacted, forming sedimentary rock

Answer 34

qqq

Question 35

(cycle of rock transformation or the rock cycle

Answer 35

Heat and pressure, without complete melting, convert igneous and sedimentary rock to metamorphic rock. These combined processes constitute a single system that creates and recycles Earth materials from one form to another over geologic time