Geology 101 Test 1
What phrase is given to the formation of new sea floor?
sea floor spreading
A volcano built of thin flows of fluid lava (low viscosity lava) is a:
shield volcano
HEMATITE 2
specular variety, with metallic luster. Composition: Fe2O3 Streak: reddish-brown Luster: metallic
Paloemagnentic studies shows what?
the fact that when iron bearing minerals crystalize they align themselves parallel to the earths magnentic field.
GYPSUM
variety "rock gypsum" occurs in granular masses. Composition: CaSO4·2H2O Color: light colored or transparent Hardness: 2 (can be scratched with fingernail) Occurrence: commonly found in sedimentary rocks; formed under evaporitic conditions. Use: Plaster of Paris, gypsum lath, fertilizer, ornamental (variety called alabaster).
What causes explosive volcanoes?
viscus lava, the runnier it is the less explosive
vander waals bonding
weakest type of bonding a weak electrostatic attraction arises because certain atoms and ions are distorted
LIMONITE
yellow ocher Composition: Fe2O3·nH2O Streak: yellow-brown (Other properties vary widely.) Occurrence:formed by alteration of previously existing iron minerals. Use: pigment, minor source of iron
Oxygen comprises about what % of the earth's crust by volume?
94%
Why are convergent plate boundary volcanoes more explosive?
Because they have more viscous lava
What is the tendency for minerals to break along flat planes called?
Cleavage
CALCITE
Composition: CaCO3 Color: usually colorless to white, but other colors occur. Hardness: 3 Cleavage: good along three inclined planes. Chemical test: effervesces freely in cold, dilute hydrochloric acid. Occurrence: chief constituent of limestone, chalk, and marble. Use: chiefly in manufacture of cement, also decorative, and in optical instruments.
CHALCOPYRITE
Composition: CuFeS2 Color: brass yellow, but often tarnished to bronze or iridescent. Hardness: 3.5 to 4 (less than pyrite). Streak: greenish-black Crystal form: usually massive, crystals not observed. Occurrence: usually found in veins in igneous rocks. Use:the most widely occurring copper mineral and one of the most important sources of copper.
ORTHOCLASE FELDSPAR
Composition: KAlSi3O8 Hardness: 6 Color: usually pink or white Luster: vitreous Cleavage: two good at 90° Occurrence:orthoclase and the other feldspars are the most abundant minerals in the Earth's crust; found in all three kinds of rocks but most commonly in igneous rocks. Use: in manufacture of porcelain.
HALITE
Composition: NaCl Hardness: 2.5 Cleavage: cubic Taste: salty Feel: "damp" Soluble in water Occurrence:precipitated from sea water under evaporitic conditions and found in sedimentary rocks. Use: common table salt; source of sodium. Name: from the Greek word meaning salt. Effervescence: Fizzing of calcite in hydrochloric acid.
Nucleus
Dense area in the center of the atom
HEMATITE
Earthy variety called "red ocher" Composition: Fe2O3 Streak: reddish-brown Luster: earthy
T/F A mineral with chemical composition of CaSO4.2H2O and hardness of 2 is called corundum.
False
T/F Orthoclase is a rock-forming nonsilicate mineral.
False
T/F The mineral halite is composed of equal numbers of sodium and olivine atoms.
False
T/F rift valleys are asscoaited with converging plates
False
T/F A specific gravity of 7 means that a substance has the same hardness as quartz.
False Hardness does not relate to specific gravity
T/F Diamond and quartz are both minerals composed of a single element.
False Quartz is made of 2 Diamond only one
T/F Biotite is dark and muscovite is colorless. Both belong to a group of silicate minerals called mica.
False, Biotite belongs to the ferromagnesian mineral group
T/F In ions, the number of electrons are usually equal to the number of protons.
False, In ion is when there is an imbalance in electrons and protons, if there is the same number it is an atom
Basaltic magma
Mafic, exists through partial melting of the athenosphere, mid ocean ridges and hot spits creates rocks basalt and gabbro
Is oil a mineral?
No!, Neither is coal
granitic magma
felsiic, exists through melting of sedimentary rocks and lower portion of the continental crust. Creates granite and rhyolite.
T/F The process of partial melting produces most, if not all, magma.
true
When did pangea start to drift?
200 million years ago
Silica tetrahedron a. contains 4 oxygen atoms and one silicon atom b. contains 1 oxygen atom and 4 silicon atoms c. has the shape of a cube d. usually contains as much calcium as silicon
A
What is a possible driving force for plate movement?
A possible driving force for plate motion is convection in the asthenosphere.
dike
A tabular body of igneous rock that cuts across the structure of adjacent rock or cute massive rocks.
Who came up with the theory of continental drift?
Alfred Wegener
Where are andesitic volcanoes found?
Along converging zones
Where are basaltic volcanoes found?
Along spreading centers
What is a corundum?
An extremely hard mineral, a form of aluminum oxide with the chemical formula Al2O3, that occurs in the form of the gemstones sapphire and ruby; with a hardness of 9
How does an ion form?
An ion is an atom or group of atoms that have a net electrical charge. An ion is formed when electrons or protons are gained or lost by an atom.
Which group below lists only members of the ferromagnesian silicate minerals? a. magnesium, iron, fertilizer b. olivine, biotite, augite c. muscovite, quartz, orthoclase d. limestone, dolomite, olivine
B
Which group of minerals below lists only silicate minerals a. hematite, sphalerite, limonite b. orthoclase, muscovite, plagioclase c. quartz. gypsum, pyrite d. augite, hornblende, galena
B
OLIVINE
Composition: (Mg, Fe)2SiO4 Color: olive green to black Hardness: (of individual, separate grains) 6.5 to 7. Luster: vitreous Occurrence: found mainly in igneous rocks. Use: as the gem peridot.
GALENA
Composition: PbS (almost always contains silver. Color: lead gray Hardness: 2.5 Specific gravity: 7.5 (heavy) Luster: metallic Cleavage: cubic Occurrence:in igneous rocks and in veins in limestone, associated with sphalerite and fluorite. Use: practically the only source of lead and an important ore of silver.
QUARTZ
Composition: SiO2 Hardness: 7 Luster: glassy Conchoidal fracture (no cleavage) (May or may not occur as crystals.) Occurrence:next to feldspar, the most abundant mineral of the Earth's crust; found in all three kinds of rocks. Use:radio and radar "crystals", ornamental, manufacture of glass and many other uses.
GARNET
Composition: Silicate with variable amounts of Fe, Mg, Mn, Ca, Al, and Cr X3Y2(SiO4) 3 (XàCa, Mg, Fe++,Mn++; YàAl,Fe+++,Cr+++) Cleavage: None Color: variable; dark red and reddish-brown are common Hardness: 7 to 7.5 Streak: white or pale shade of the body color Luster: vitreous Occurrence: common in metamorphic rocks and in some igneous rocks. Use: clear crystals are cut and polished as semi-precious gems (January Birthstone) Garnet is also used as an abrasive, for instance in sandpaper, because of its hardness and lack of cleavage.
KAOLINITE
Composition: hydrous aluminum silicate. Color: white Feel: greasy Smell: earthy Found in small masses. Note: does not react to acid, as does the rock chalk. Occurrence:results from the alteration of other aluminum silicates, particularly feldspar. Use:paper, china, brick.
Which is thicker, continental or oceanic crust?
Continental
Which of the following groups contains only nonsilicate minerals? a. olivine, biotite, muscovite b. muscovite, biotite, calcite c. augite, hornblende, olivine d. magnetite, calcite, galena
D
T/F To form an ion, an atom becomes electrically neutral.
False
Pyrite
FeS2 fools gold
what are Silicates rich in iron and magnesium called
Ferromagnesians.
Explain Covalent bonding
In covalent bonding adjacent atoms share electrons (diamond).
Metallic bonding
In metallic bonding the atoms are closely packed together and electrons move freely throughout the crystal (iron and gold).
Ionic bonding
Ions are fixed in place by their electrical attraction to one another
Ionic bonding
Ions are fixed in place by their electrical attraction to one another (halite).
What is the way that minerals reflect light called?
Luster
What is the core of the earth mostly made of?
Nickel and Iron
HORNBLENDE
One of a number of similar minerals collectively referred to as the amphibole group. Composition: complex hydrous calcium magnesium iron aluminum silicate. Color: dark green to black Hardness: 5 to 6 Cleavage: two at angles of 56° and 124° Crystals: frequently prismatic Occurrence: in igneous rocks and metamorphic rocks.
AUGITE
One of a number of similar minerals collectively referred to as the pyroxene group. Composition: complex calcium magnesium iron silicate. Hardness: 5 to 6 Cleavage: two at angles of 87° and 93°. Crystals: short, prismatic Occurrence: in igneous and metamorphic rocks.
The two most common silicate minerals in the crust are
Oxygen and Silicone (by weight) but quartz and feldspar
Proton, neutron and electron
Proton = positive Neutron = neutral Electron= negative
What are the most ommon minerals in the crust?
Silicates, specifically quartz
What are geologists who study the composition and origin of rocks called?
Structural Geologist
What is the Atomic mass?
The number of protons in each atom of that element.
Where are most deep ocean trenches located?
The pacific ocean
PLAGIOCLASE FELDSPAR
The term "plagioclase feldspar" refers to a continuous gradational series of minerals which range in chemical composition from pure sodic plagioclase, called albite, to pure calcic plagioclase, called anorthite. Composition: NaAlSi3O8 to CaAl2Si2O8 Color: white to gray Hardness: 6 Luster: vitreous Cleavage: two good at approximately 94°. Occurrence: found in igneous, metamorphic, and more rarely in sedimentary rocks. Use: in ceramics, semi-precious stones.
T/F A crater is a steep-walled funnel-shaped depression at the top of volcanoes formed by explosive eruptions.
True
T/F An electron is opposite in electrical charge to a proton.
True
T/F Ferromagnesian minerals are generally dark in color.
True
T/F Fluid lava (basaltic magma) allows dissolved gas to escape and produces mild eruptions of lava flows. This kind of eruption is associated with diverging plate boundaries.
True
T/F In the silicate minerals, the silica tetrahedra are combined with the non-silicate elements such as iron, magnesium, sodium, and aluminum.
True
T/F The viscosity of a lava determines how easily the gas can escape.
True
T/F The volcanoes of Hawaii are localized above a mantle hot spot (plume); they are not part of the East Pacific oceanic ridge.
True
The island of Hawaii is the youngest of the Hawaiian Islands.
True
True or False? At a convergent plate boundary, high mountains may be built during continent-continent collision.
True
True or False? Oceanic lithosphere records magnetic "stripes" of normally and reversely magnetized rocks.
True
True or False? Part of western California is attached to the Pacific Plate, while most of North America belongs to a separate plate.
True
True or False? Sea floor is created at spreading ridges and destroyed in subduction zones.
True
True or False? With increasing distance from an oceanic ridge, the rocks become older.
True
True or False? The asthenosphere is a weak, plastic layer over which lithospheric plates can move.
True, the athenosphere is a weak layer and the lithosphere moves over it.
What are typical rates of continental movement per year?
Typical rates of plate movement are 2 to 3 centimeters per year.
Which of the following groups of minerals is more likely abundant in the oceanic crust? a. quartz, orthoclase, plagioclase b. quartz, muscovite, halite c. augite, olivine, biotite d. hematite, gypsum, fluorite
a
Which of the following minerals belongs to the feldspar group? a. orthoclase b. olivine c. muscovite d. hornblende
a
batholith
a large bod of intrusive igneous rock exposed over an area of at least 100 km
stock
a small somewhat circular batholith
Crater
a steep walled funnel shaped depression at the top of volcanoes formed by explosive eruptions
Caldera
a very large crater which is sort of circular
smallest unit of an element is..
an atom
What is the name given to electrically charged atoms?
an ion
cation
an ion that has a positive charge
Any ion that has a negative electric charge is called
anion
Where does oceanic crust sink into the earth?
at deep ocean trenches and subduction zones
ferromagnesian minerals (silicate)
augite biotite chloirite hornblende olivine, usually darker
Silicate minerals a. are generally deficient in silicon and quartz b. contain relatively high amounts of calcium, magnesium, and iron oxides c. tend to be dark in color d. all of the above e. none of the above
b
A subduction zone is a feature of what kind of boundary?
converging plate boundaries.
What are the two tops of volcanoes?
crater and a caldera
sill
cuts straight across, parrellel to bedding
give examples of polymorphs
diamond and graphite
East african rift valley is what kind of boundary?
divergent
Carbonites (non silicates)
dolomite and calcite
isotopes
elements with same number ofatoms but different number of neutrons
framework silicates
feldspar plagoclase and orthoclase
Shield volcano
formed by low viscosity lava
Cinder cone volcano
fragments of volcanic rock that make up cinder cones, pyroclasts (ash, bombs blocks)
sulfates (non silicates)
gypsum
Chlorides(non silicate)
halite, diamond, graphite
aa lava
high visocity and thick
What is the fundamental force that drives convection currents?
hot mantle rises, it hits the plate, and it drags on the bottom of the plates and causes movement.
What does A polar-wander curve show?
how continents have moved, or drifted, relative to the magnetic poles.
What causes melting
increase in temperature, decrease in pressure
Andesitic Magma
intermediate, exists through melting of oceanic lithosphere and marine sediments along the subduction zones. creates andesite and diorite
What 2 super continents did pangea split into?
laurasua and gondwanaland
What is the name of the rigid outer layer of the Earth composed of the crust and outermost mantle?
lithosphere
pahoehoe lave
low viscosity, flow rapidly and smoothly
What is the mantle of the earth mostly made of?
magnesium, silicon and oxygen
Oxides (non silicate)
megnetite hematite limonite
What kind of magma (lava) is associated with converging plate boundary?
metamorphic
sheet silicates
mica and clay groups
compostie or strato volcano
mostly andesite and mostly found behind subductions zones
Where are the oldest rocks found?
on continents
Sulfides (non silicate)
pyrite, galena, chalcopyrite
What mineral is used to help make glass?
quartz