geology exam #1

what four spheres make up the earth?

atmosphere, geosphere, biosphere, hydrosphere

what is the atmosphere?

the layer of gases that surrounds Earth

what is the geosphere?

The solid part of Earth

what is the biosphere?

all life on earth

what is the hydrosphere?

All the water on earth

what systems power the earth?

sun, gravity, and internal heat

what is the big bang theory?

The theory that the Universe began with a huge explosion, explains the birth of the universe

what is the nebular theory?

the sun and planets formed from a rotating disk of dust and gases, explains the birth of the solar system

what is density? give some examples.

mass/volume, iron or lead

how old is the earth?

4.6 billion years old

what are the layers of the earth?

crust, mantle, outer core, inner core

what is the outermost layer of the earth?

crust

what is the second outermost layer of the earth?

mantle

what is the third outermost layer of the earth?

outer core

what is the inner most layer of the earth?

inner core

what is the rock cycle?

the series of processes that change one type of rock into another type of rock

how is metamorphic rock formed?

By the heat and pressure of sedimentary rock being pushed deeper and deeper into the earth.

how is sedimentary rock formed?

formed from sediments being compressed by other overlying sediments

how is igneous rock formed?

cooling of magma

mountain belts

Formed by two continental plates colliding and forcing each other upwards

stable platforms

the flat portions of cratons covered with a thin veneer of sedimentary rocks

sheilds

a large, relatively flat expanse of ancient metamorphic rock within the stable continental interior

what are the parts of an ocean basin?

shelf, shelf margin, slope, rise, trench, abyssal plain. seamount, island, and guyot

continental shelf

A gently sloping, shallow area of the ocean floor that extends outward from the edge of a continent

continental shelf margin

the end and drop off point of the continental shelf

continental slope

a steep incline of the ocean floor leading down from the edge of the continental shelf

continental rise

the gently sloping surface at the base of the continental slope

ocean trench

Deep valley in the ocean floor that forms along a subduction zone

abyssal plain

a large, flat, almost level area of the deep-ocean basin

seamount

an underwater mountain rising above the ocean floor

island

a piece of land surrounded by water

guyot

a seamount with a flat top

how was the mid-oceanic ridge formed?

the magma coming up through the divergent plate boundary spreading the sea floor apart while also creating new sea floor

how old is the sea floor?

200 million years old

what is catastrophism?

all earths features from flood

who coined catastrophism?

bishop usser

what is uniformitarianism?

The belief that the Earth's past geological changes can be fully explained by current processes.

who coined uniformitarianism?

james hutton

what theory explains, "the present is the key to the past?

uniformitarianism

scientific method step one:

observation

scientific method step two:

hypothesis

scientific method step three:

plan and collect data

scientific method step four:

analyze the data

scientific method step five:

revision and conclusion

scientific method step six:

get peer reviewed and published

the key to good scientific method is..

..objectivity

law..

..absolutely correct throughout the natural universe

fact..

..straight forward observation

theory..

..an overarching explanation that covers multiple lawd and can be proven again and again with new data

hypothesis..

..educated guess

who came up with the theory of continental drift?

alfred wegener

what evidence was used to explain continental drift?

fit of the continents, fossil evidence, similar rock types, and paleoclimates

explain the theory of plate tectonics.

less dense continents "float" on denser mantle

name three characteristics of divergent plate boundaries.

constructive, tensional forces, rifting

name three characteristics of convergent plate boundaries.

destructive, compressional forces, trench and subduction zone

name three characteristics of transform plate boundaries.

conservative, not destructive or constructive, no volcanoes

how do mid-oceanic ridges begin?

magma flowing up through a divergent rift valley pushing the two plates apart

what methods prove plate tectonics?

deep sea drilling, hot spots, paleomagnetism, gps

what 5 criteria must be met to be classified as a mineral?

inorganic, solid, organized internal structure, naturally occurring, definite chemical composition

what are the eight basic properties of minerals?

color, streak, luster, crystal habit, hardness, cleavage, fracture, specific gravity

what are the three types of chemical bonding?

ionic, covalent, metallic

what is ionic bonding?

transfer of electrons, no sharing

what is covalent bonding?

sharing of electrons

what is metallic bonding?

electrons can flow between ions

what is specific gravity?

ratio of the weight of a mineral to the weight of an equal volume of water

what two primary elements make up earths crust?

oxygen and silicon

what are the six subsidiary elements that make up earths crust?

aluminum, calcium, iron, magnesium, sodium, and potassium

what are the four main mineral groups?

silicates, carbonates, halides, sulfides

what makes up a silica tetrahedral?

four oxygens around one silicone

what causes a light silicate?

absence of iron and magnesium

what causes a dark silicate?

presence of iron and magnesium

what is the average specific gravity of dark silicates?

2.5-3.5

what is the average specific gravity of light silicates?

under 2

what are some light silicate minerals?

quartz, feldspar, muscovite

what are some dark silicate minerals?

olivine, pyroxene, biotite, garnet

which silicate group weathers faster, light or dark?

dark

what are some important non-silicate minerals?

calcite, dolomite, halite, gypsum, hematite, fluorite

what are some types of renewable resources?

solar, wind, water, biomass, geothermal

what are some types of non-renewable resources?

coal, oil, nuclear

what is igneous rock?

Rock formed from melting rock turning into magma then cooling.

what is magma?

Molten rock beneath the earth's surface

what is lava?

Magma that reaches Earth's surface

what are the three components of magma?

melts, solids, volatiles

what is intrusive rock?

igneous rock that forms as magma cools underground

what is extrusive rock?

Igneous rock that is formed from lava that erupted and cooled on earths surface

which type of rock has the least silicate content?

ultramafic

which type of rock has the second to last amount of silicate content?

mafic

which type of rock has the second most silicate content?

intermediate

which type of rock has the most silicate content?

felsic

what is phaneritic texture?

large interlocked crystals that can be seen with naked eye

what is aphanitic texture?

small crystals that can't been seen with naked eye

what is porphoritic texture?

large crystals in a small crystal groundmass, crystals don't touch

what is pegmatitic texture?

very very course grained crystals

what is a phenocryst?

a large crystal surrounded by a finer-grained matrix in an igneous rock

what is a vesicular texture?

full of holes, frothy

what is pyroclastic texture?

fine grained debris explosively ejected onto surface by volcanic processes

what is assimilation?

the process of reacting of the magma with the wall rock,whereby the country rock are incorporated in the magma and eventually melt

what is a xenolith?

a fragment of wall rock that broke off and was surrounded by magma

what are three characteristics of felsic magma?

does not flow easily, more silica, shield

what are three characteristics of mafic magma?

easily flows, less silica, cone