Exam 1 Earth Science

Fracture zones

Is caused by linear breaks in the seafloor They are inactive Active faults occur between offset ridge segments

Minerals are divided into eight major groups based on their _____.

chemical composition

Due to the arrangement of weaker bonds in their crystal lattice, the tendency of certain minerals to break along smooth, parallel planes is known as ________.

cleavage

mineral's tendency to break along flat planes

cleavage

Biotite has which of the following types of cleavage?

cleavage in one direction

Granite is ________.

coarse-grained and dominated by quartz and feldspar crystals

Dark silicate mineral

Contain iron and magnesium Pyroxenes Amphiboles Olivine Biotite Gamet

Fine-grained texture

Cooled rapidly at the surface Small Mineral Extrusive

Examples of chemical sedimentary rocks

Coquina: loosely cemented shell fragments Chalk: hard parts of microscopic organism Chert, flint, jasper, and agate: microcrystalline quartz Salt and gypsum form in evaporite deposits Coal consists mostly of organic matter

Mafic

Dark in color Heavy Metals- magnesium/ iron Basaltic

Glassy texture

Lava + cold water = shock Cools instantaneously No mineral

Minerals containing just one element

Native elements

________ is formed when carbon dioxide dissolves in rainwater, and this mildly reactive substance aids chemical weathering.

carbonic acid

The longest topographic feature on Earth's surface is ________.

The oceanic ridge system

When in contact with hydrochloric acid, which mineral gives off bubbles of carbon dioxide gas?

calcite

Rocks that contain crystals that are roughly equal in size and can be identified with the unaided eye are said to exhibit a ________ texture.

coarse-grained

Which rock type is most likely to have been deposited in a high-energy environment (such as a very turbulent stream)?

conglomerate

Light silicates

contain greater amounts of potassium, sodium and calcium and are richer in silica

An igneous rock that shows a vesicular texture ________.

contains many small holes, like Swiss cheese

________ bonding is the sharing of valence atoms between a pair of atoms.

covalent

Solid in which the atoms are arranged in a regular repeating pattern

crystal

Which of the following is not an agent of metamorphism?

dissolution

New ocean crust is generated at ________.

divergent plate boundaries

If an atom has an equal number of electrons and protons, it would be considered ________.

electrically neutral

Obsidian is characterized by its ________ texture.

glassy

Which of the following has the highest specific gravity?

gold

Detrital sedimentary rocks are classified and named principally on the basis of ________.

grain size

Ridge push

gravity causes lithospheric slabs to slide down the ridge

minerals that form salts

halides

The resistance of a mineral to scratching or abrasion is known as ________.

hardness

In contact metamorphism, ________ is the dominant agent of change.

heat

Crystal shape or habitat

is the characteristic shape of individual mineral crystals or aggregates of crystals

Streak

is the color of a mineral in powdered form

Magma differentiation

is the formation of one or more secondary magmas from a single parent magma

Luster

is the quality of light reflected from the surface of a mineral

Cleavage

is the tendency of a mineral to break along planes of weak bonding

The ________ is Earth's outermost rocky layer that is broken into plates.

lithosphere

way that light reflects off a mineral's surface

luster

A ________ is a long-lived, stationary, magma source deep in the mantle, well below the base of the lithosphere.

mantle plume

Which of the following is a non-foliated metamorphic rock?

marble

Which one of the following mineral groups exhibits a sheet-like silicate structure?

micas

Regional metamorphism occurs during ________.

mountain building

Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.

normal and reversed magnetized strips roughly parallel to the ridge

All of the atoms making up any given element have the same number of ________.

protons in the nucleus

largest mineral groups

silicates

Which one of the following is a metamorphic rock?

slate

Continental rifting begins when plate motions produce ________ forces that pull and stretch the lithosphere.

tensional

Alaska's Aleutian Islands formed as part of a ________ along a ________ boundary.

volcanic island arc; convergent

Ultramafic

Green Iron Peridotite

Regional Metamorphism

Pressure and high temperature during mountain building

Limestone is dominated by the mineral ________.

calcite

Bowen's Reaction Series

1.Ultramafic( first to turn into solid/iron) 2. Mafic( metal) 3. Intermediate( metal & salt) 4. Felsic ( last to turn into solid/salt)

Oceanic lithosphere is approximately ________ thick in deep-ocean basins.

100 km

The age of the oldest sediments recovered from deep-ocean drilling was ________.

180 million years old

An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus?

7

Mantle Plume

A cylinder of upwelling hot rock Ex: Hawaii

Explain how the processes that create hot-spot volcanic chains differ from the processes that generate volcanic island arcs.

An island arc forms at a converging plate boundary where one oceanic plate sinks beneath another oceanic plate. A hot spot volcano forms in continental or oceanic crust where magma from the mantle erupts. Hot spot volcanoes often are far from plate boundaries. Both types are from subduction, but volcanic arcs are continent-oceanic interactions, while island arcs are oceanic-oceanic interactions.

Metamorphic rocks

Are produced when preexisting parent rock is transformed

Fossils

Are traces or remains of life found in some sedimentary rocks

Rock Cycle

Begins with magma that rises to the surface Cools at surface or within Earth's crust Cooling is called crystallization or solidification Igneous rocks are formed Igneous rocks exposed at the surface undergo weathering Loose materials(sediment) undrgoes erosion Sediment undergoes lithification either by compaction or cementation It then undergoes extreme heat and pressure to form a metamorphic rock It then starts again

Most common carbonate mineral

Clcite

Granite

Coarse-grained Uplift during mountain building Magma solidified slowly at depth

Diorite

Coarse-grained intrusive = andesite Few or no visible quartz crystals

Gabbro

Coarse-grained intrusive = basalt Not commonly exposed at Earth's surface Significant component of oceans crust

Slab pull

Cold, dense oceanic crust sinks because it is denser than the asthenosphere

Chemical Weathering(internal structure)

Elements are removed or added Oxygen dissolved in water causes oxidation Carbon dioxide dissolved in water is carbonic acid Changing surface(erodes) Decaying organisms

Magnetic reversal

Every 100,000 years magnetic field reverses

The Rock cycle

Explains the interaction between components of the Earth System

Rhyolite

Extrusive fine-grained Light-colored Cooled rapidly

Common light silicate minerals

Feldspar Quartz Muscovite Clay minerals

Porhyritic texture

First stage is slow cooling inside the crust Second stage is quick cooling at surface

Continental-Continental Convergance

Folding and deformation of rocks Mountain Building

Chemical

Form from ions carried in solution If keep on adding it will settle in solid Solid out of liquid Evaporation

Detrital

Form from solid particles weathered from rocks pre-existing weather(first) erosion(second) deposition(third) lithification= compaction(fourth)

Common Metamorphic rocks

From less pressure and heat to higher 1.Slate(characteristic rock cleavage) 2.Phylliate(larger mineral grains/ glossy sheen & wavy surface) 3.Shicst(formed by regional metamorphism of shale) 4.Gneiss(banded metamorphic rock) 5.Magma

Native element

Gold

Intermediate

Gray 50/50- color Light/dark Andesitic

Agents of Metamorphism

Heat(from intrusion of magma or burial), chemical reactions and recrystallization of new mineral Confining pressure( equal in all direction), compaction and recrystallization of new minerals, smaller(same shape) Differential stress(2 direction/mountain building), shape change, deformation and development of metamorphic textures Chemically active fluid(hydrothermal fluid rich in ions), can change chemical composition of surrounding rocks

The collision of the subcontinent of India and Asia started forming the ________ approximately 50 million years ago.

Himalayan Mountains

Which rock may form on Earth's surface

Igneous and Sedimentary Rocks

Types of Rocks

Igneous: lava/magma cooling+solidification Sedimentary: pre-existing rocks broken down glued together Metamorphic: extreme heat/ pressure

Mechanical Weathering

Increases surface area Physical Smaller pieces Frost wedging( Ice expands when it freezes) Sheeting occurs when concentric slabs of intrusive igneous rock breaks loose Root wedging Burrowing animals expose rock to increased weathering

Five Characteristics for Minerals

Inorganic Natural Occurring Solid Crystalline Structure Definite Chemical Composition

Rift Valley

Is a deep canyon along the crest of a ridge resulting from tensional forces

Hot Spot

Is an area of volcanism, high heat flow, and crystal uplift above a mantle plume Ex: Hawaii islands

Lithosphere

Is the crust and uppermost(coolest) mantle Mafic composition More dense than continental lithosphere Continetal lithosphere 150-200 km thick(felsic composition) Responds to forces by bending or breaking

Foliation

Is the development of a flat arrangement of mineral grains or structural features A lot of heat and pressure Differential stress Mineral line up(parallel) Bond of light and dark color Is a characteristics of regional metamorphism It is driven by compressional stress

Asthenosphere

Is the hotter, weaker mantle below the lithosphere Rocks are nearly melted at this temperature and pressure Responds to forces by flowing Moves independently form litosphere

Seafloor Spreading

Is the process by which new seafloor is created along the ocean ridge system Average spreading rate is 5cm/year

Felsic

Light color Light weight salts potassium, calcium, sodium Granitic

Deep ocean tenches

Long, linear depressions Results of subduction

Common non foliated rocks

Marble Quartzite

Andesite

Medium-gray extrusive Fine-grained or porphyritic Major constituent of volcanoes along Pacific Rim

Examples of Evidence(Fossils)

Mesosaurus: Found in eastern South America and Western Africa Glossopteris(plant): Africa, Australia, India, South America, and Antartica

Basalt

Most common extrusive Fine-grained(dark green to black) Contains pyroxene, olivine, and plagioclase feldspar Relatively common at Earth's surface

Obsidian

Natural volcanic glass Dark in color(metallic ions) Felsic Composition

Convection

Occurs as hot, less dense material rises and surface material cools and sinks Drag in the mantle affects plate motion

Continental Rifting

Occurs when divergent boundaries develop within continent Tensional forces stretch and thin the litosphere Brittle crust breaks into large blocks Eventually become ocean basins Example: East Africa Rift

Compaction

Occurs when grains are pressed closer together so that poor space is reduced

Metamorphism

Occurs when parent rock is subjected to a different physical or chemical environment

Cementation

Occurs when water containing dissolved mineral moves through pores

Oceanic-Oceanic Convergance

Older slab subjects to newer Generates volcanic island arcs

Which of the following is the largest lithospheric plates?

Pacific Plate

________ was a supercontinent that existed in the late Paleozoic era of geologic time.

Pangea

Pyroclastic(fragmental) texture

Pyro= fire/ clastic= broken Violent explosion Angular and jagged

Contact Metamorphism

Rock temperature increases because of intruding magma

Normal Polarity

Rock within the same magnetic field as today

Nonfoliated

Rocks occur when deformation is minimal and parent rocks is composed largely of stable mineral Low-grade Mineral are just compacted

Paleomagnetism

Rocks preserve a record of direction of magnetic poles at the time of formation

Silicates

Silica and oxygen combine to form the basic building block for the silicates(most common minerals)

Coarse-grained texture

Slow Cooling Big mineral Intrusive

Oceanic-Continental Convergence

Subduction of oceanic lithosphere Continental volcanic islands

The basic building block of all silicate minerals is called silica.

Tetrahedron

Three of the following are true for minerals. Which one of the following is not true for minerals?

They can be a liquid, solid, or gas.

Divergent Boundaries(constructive margins)

Two plates move apart Upwelling of hot material from mantle creates new seafloor

Convergent boundaries(destructive margins)

Two plates move together Oceanic lithosphere descends and is reabsorbed into mantle Two continental blocks create a mountain belt

Transform boundaries(conservative margins)

Two plates slide past each other No lithosphere is created or destroyed

Vesicular texture

Very rapid surface cooling Gas trapped(holes) Groundmass - phenocrysts

Pumice

Vesicular volcanic glass Floats in water due to vesicles

Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?

Volcanoes are fed by a long-lived hot spot below the Pacific lithospheric plate.

2 Models for Convection Flow

Whole-mantle convection Layer cake model(upper mantle)

A transform plate boundary is characterized by ________.

a deep, vertical fault along which two plates slide past one another in opposite directions

Imagine that you were given a ship equipped with a device that could measure how deep the water is. You are asked to use this ship to find a subduction zone. What would you look for as you sailed around the world's oceans?

a deep-ocean trench

Dark silicates

are rich in iron and/or magnesium and relatively low in silica

The ________ is weaker and less rigid than the overlying lithosphere.

asthenosphere

Layers in sedimentary rocks are called ________.

beds

Confining pressure results from the ________ of rocks.

burial

The area of crust directly above a rising mantle plume is a(n) ________.

hot spot

Chemical weathering would be most effective ________.

in a warm, wet climate

Atoms that have an electrical charge due to a gain or loss of electrons are called ________.

ions

Hardness

is a mineral's resistance to abrasion or scratching

Tenacity

is a mineral's resistance to breaking, bending, cutting, or deforming

Fracture

is a property resulting from chemical bonds that are approximately equal in strength

Texture

is described based on the size, shape, and arrangements of mineral grains

What element is the most abundant in Earth's crust by weight?

oxygen

Which igneous texture is characterized by two distinctively different crystal sizes?

porphyritic

Which the following are the positively charged particles in an atom's nucleus?

protons

Which common mineral is composed entirely of silicon and oxygen?

quartz

________ exhibits a conchoidal fracture.

quartz

Which one of the following is an igneous rock?

rhyolite

An aggregate of one or more minerals is called a(n) ________.

rock

Which kind of rocks may most likely contain fossils?

sedimentary

Mud cracks and ripple marks are common features of ________.

sedimentary rocks

________ is the powdered form of the mineral.

streak

color of mineral's powder

streak

A volcanic island arc is the result of ________.

subduction of oceanic crust underneath oceanic crust

Cooler, older, oceanic lithosphere sinks into the mantle at ________.

subduction zones along convergent plate boundaries

The San Andreas fault in California is a good example of a ________ plate boundary.

transform

The ability of a mineral to transmit both light and an image in the mineral is described as ________.

transparent

Metamorphism may change a rock's mineral composition

true

One type of rock can change to any other type of rock

true

Plants and animals can act to wear down rocks

true

Sedimentary rocks include sandstone and shale

true

Which of the following properties would be least useful for identifying a sample of calcite?

white color