EARTH SCI LESSON 3

rock

an aggregate of minerals which may or may not contain organic matter.

geosphere

made out of rocks

rock cycle

a model used to describe how rocks are formed, broken down, and reformed into other types.

true

any types of rock can be a raw material of another rock. true or false?

igneous rock

formed from cooling of molten magma

sedimentary rocks

formed from pre-existing rocks and fossils of organism

metamorphic rocks

formed from pre-existing rocks through heat and pressure.

intrusive igneous rocks

formed in earth's interior wherein cooling rate is slower resulting in large crystal formation

extrusive igneous rocks

formed in earth's surface wherein the cooling rate is faster resulting in smaller crystal formation

quenching

it is where molten rock is cooled instantly which may result in rock with glassy like texture

volcanic glass & obsidian

example of rocks formed from quenching

quenching

this process usually happens in violent volcanic eruptions

felsic or granitic rocks

igneous rocks that are generally composed of light-colored minerals

basaltic or mafic rocks

igneous rocks composed of dark grey to black minerals

mineral content

igneous rocks can also be divided into groups according to their _.

weathering

a process of breaking down rocks into smaller pieces, can be physical or chemical

erosion

a process of transferring unconsolidated earth's material via agents like human, animal, wind, and water

deposition

occurs when all the unconsolidated materials settle in one area

lithification

takes place when sediment turns into sedimentary rock, involves the processes of compaction and cementation

foliation

refers to the sub-planar orientation of mineral grains or the layering found in rocks

foliated metamorphic rocks

metamorphic rocks with clear layers which are formed in areas where rocks are deformed by stresses like plate boundaries

non-foliated metamorphic rocks

metamorphic rocks with no definite layers which are formed in areas where deformation is minimal

minerals

a naturally occuring inorganic homogenous solid with a definite chemical composition and an ordered crystalline structure

color

physical property of mineral that refers to certain wavelengths of light that are reflected by a mineral and is perceived by the observer

streak

physical property of mineral that refers to the color of the powdered form of the mineral

luster

physical property of mineral that refers to the appearance of its surface and is dependent on how it reflects light

crystal habit

physical property of mineral that refers to the characteristic shape in which a mineral grows and is a projection of its crystal structure

cleavage

physical property of mineral that refers to the tendency of some to break along flat surfaces

fracture

physical property of mineral that refers to the pattern in which mineral breaks aside from its planes of cleavage

hardness

physical property of mineral that refers to the hardness of minerals to scratching

specific gravity

physical property of mineral that refers to the ratio of its weight to the weight of an equal volume of water

talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum, diamond

mohs scale of hardness

solubility

chemical property of minerals that refers to the ability of a substance to dissolve in a solvent at a specified temperature

melting point

chemical property of minerals that refers to the temperature at which solid turns into liquid

elements

most minerals here are composed of only one element, ex: copper, gold, silver, sulfur

sulfides

minerals under these group are composed of metal joined by a sulfur, ex: cinnabar, pyrite

metallic luster

the characteristics that distinguishes sulfides from others

halides

these are nonmetal groups which consists of chlorine, fluorine, bromine, and iodine as the main chemical constituent, ex: fluorite, halite, diabolite

oxides and hydroxides

these are mineral groups composed of one or more metals joined with oxygen, water, or hydroxyl (OH), ex: cuprite, hematite

nitrates, carbonates, borates

it is formed when a metal is combined with carbon, nitrogen, and boron, ex: malachite, borax, nitratine

sulfates

one or more metal is combined with a sulfate compound, ex: anhydrite

wet chemical analysis

involves dissolving a mineral in an acid and analyzing the solution

spectroscopic techniques

involve quantitative analysis of mineral components depending on the light absorbance of the compounds

solidification of magma or lava

Igneous rocks are formed from ___ which flows out from depth

quartz, feldspar, pyroxene, olivine, amphibole, and mica

these are minerals that makes up almost all types of igneous rocks

intergrowth of crystals and/or volcanic glass

igneous rocks are characterized by _.

big crystals

crystals are formed deep underground

smaller crystals

crystals are formed near the surface

extrusive igneous rock

formed when magma or volcanic fragments erupt and solidify on earth's surface which result to very-fine grained rock with very small crystals that could not be seen through naked eye

intrusive igneous rock

formed when magma crystallizes within the crust and is composed of medium to coarse grains

plutonic rock

intrusive igneous rocks are also known as?

sedimentary rocks

formed from organic, mechanical, or chemical sediments

lithification

a process where harden sediments become sedimentary rocks

diagenesis

a collective process where sediments are lithified

compaction, cementation, recrystallization, chemical changes

four main parts of diagenesis

clastic sedimentary rocks

made up of sediments from pre-existing rocks

biological sedimentary rocks

lithified accumulation of dead organisms

chemical sedimentary rocks

form from chemical precipitation

non-clastic sedimentary rocks

can be formed through biological, chemical, or both

metamorphic rocks

rocks that have been altered, changed, or transformed in the solid state due to changes in pressure, temperature conditions, and chemical actions of hot fluids

metamorphism

like the chameleon changing its color to protect itself by blending into its environment

reestablish equilibrium with the new conditions

the goal of metamorphism

recrystallization

occurs when small crystals of one mineral will slowly convert to fewer, larger crystals of the same mineral without melting the rock

neomorphism

the process whereby minerals not only recrystallize, but also form different minerals from the same chemical elements

metasomatism

the addition or loss of elements wherein new minerals form with only some of the original elements

contact metamorphism

occurs only at a local area adjacent to large intrusions and along fractures that are in contact with hot fluids

regional metamorphism

occurs when there are major igneous intrusions, presence of extreme pressure and heat due to deep burial

foliated metamorphic rocks

formed when parallel planes of platy or elongated minerals creating what is called as foliations

nonfoliated metamorphic rocks

do not have layered appearance, ex: marble, quartzite, anthracite

true

the rock cycle shows that all rocks are related to each other. true or false?

weathering

the process of breaking down rocks present at earth's surface

action of rainwater, variable extreme temperature, & different biological activities

weathering can happen in the presence of the _, ____, _____.

mechanical weathering

a process wherein rocks are broken down into smaller pieces without changing their chemical composition due to several factors like fluctuating temperatures and pressure, and biological activity

frost wedging

a process that involves repeated cycles of freezing and thawing of ice, happens when there is sufficient moisture; pre-existing cracks; and when temperatures frequently rise and fall

salt crystal growth

a process that happens when seawater penetrates crevices in rocks which are found mostly in rocky shorelines and arid regions

expand

salt crystals _ when subjected to an increase in temperature that causes the widening of cracks

biological activity

the action of organisms including plants and animals reduces the size of rocks and minerals which make rocks more susceptible to chemical weathering

unloading

happens through erosion or uplift, thick layers of sediments overlying deeply buried in rocks are removed

chemical weathering

a process wherein rock materials are changed into other substances that have different physical and chemical compositions

dissolution

a process wherein a solid dissolves in a liquid

hydrolysis

a process where water reacts with a mineral to form a new mineral

oxidation

where chemical combination of oxygen with a mineral to form an entirely different mineral in which at least one of the elements has a higher ionic charge

climate

a factor that mainly includes the amount of moisture in the air and temperature where weathering takes place

higher

the _ the elevation, the more susceptible it is to weathering since it is more exposed to environmental factors

large surface area

weathering rapidly occurs when there is a exposed to surface processes.

goldich stability series

illustrates the relative stability or weathering rate of numerous minerals. This series is roughly the inverse order of original crystallization for minerals found in the Bowen's reaction series

erosion

the transportation of weathered rocks

water/rivers, wind, gravity, groundwater, wave currents, glaciers

six main agents of erosion

water erosion

a type of erosion where water carries the sediments to different bodies of water, the high amount of rainfall contributes to susceptibility of the soil to water erosion

wind erosion

happens when light materials such as small rocks and pebbles are carried by the wind to different places

glacial erosion

happens when a glacier, or a river of highly-compact ice, move downhill due to its weight. it plucks chunks of rocks and causes scraping between the ice and rock

soil erodibility

the vulnerability of soil to erosion causes by rainfall intensity, soil properties, crop cover, and slope

texture of soil

most significant contributing factor to erodibility

overgrazing

causes erosion due to livestock or indigenous animals removing vegetation leaving soil more vulnerable to erosion

cutting of trees and removal of vegetation

can also result in large amounts of erosion

pesticides, herbicides, fuel oils

usage of ____, ____, and ____ also pollutes the soil

salt

this can also contaminate soil due to high salinity of irrigation water as it passes over croplands

• steep terrains are shaped to produce flat areas

• reducing farmland conversion

• planting vegetation