PHY 105 Exam 1

When an atom loses two electrons during a chemical reaction, it will become

AN ION WITH A POSITIVE 2 CHARGE

An aphanitic rock containing about 50% plagioclase feldspar, 35% amphibole, 10% pyroxene, and minor amounts of other light-colored silicates

ANDESITE

Texture consists of crystals that are too small to be seen without a microscope.

APHANITIC

How does geology relate to people and the natural environment?

1. KNOWLEDGE OF GEOLOGICA PROCESSES HELPS PEOPLE LOCATE AND EXTRACT METALLIC AND NONMETALLIC RESOURCES 2. HUMAN ACTIVITES ALTER THE LANDSCAPE AND GEOLOGIC PROCESSES 3. MANY OF EARTH'S PHYSICAL PROCESSES BECOME HAZARDOUS WHEN PEOPLE IVE WHERE THE PROCESSES OCCUR

Rank from most abundant to least abundant elements in Earth's crust.

1. OXYGEN, 2. SILICON, 3. ALUMINUM, 4. IRON, 5. CALCIUM, 6. SODIUM, 7. POTASSIUM, 8. MAGNESIUM

What is a theory?

A WELL-TESTED AND WIDELY ACCEPTED VIEW THAT BEST EXPLAINS CERTAIN SCIENTIFIC OBSERVATIONS.

Place the following events related to the breakup if Pangea in the proper order.

1. THE SEPARATION OF NORTH AMERICAN AND AFRICA 2. THE SEPARATION OF AFRICA, INDIA AND ANTARCTICA 3. THE COLLISION OF INDIA AND EURASIA 4. THE SEPARATION OF ARABIA AND AFRICA

What is the currently accepted age of the Earth?

4.6 BILLION YEARS

Approximately how many people live in the vicinity of an active volcano?

500 MILLION

What percentage of lava erupted on Earth is of basaltic composition?

90%

What is a compound?

A CHEMICAL SUBSTANCE COMPOSED OF TWO OR MORE ELEMENTS.

Which type of rock type and environment has the highest concentration of rare elements?

A PEGMATITE CRYSTALLIZED FROM WATER-RICH, HIGHLY DIFFERENTIATED RESIDUAL MAGMA

The Aleutian Islands of Alaska are what type of tectonic feature?

A VOLCANIC ISLAND ARC

What type of lava has a rough, jagged and blocky texture?

AA LAVA

You come across a whitish mineral in the field. You think it might be calcite, but you aren't sure. Which of the following would be the best way to determine if your sample is calcite?

APPLY DILUTE HYDROCHLORIC ACID TO SEE IF IT FIZZES

What flows in response to convective heat from Earth's interior?

ASTHENOSPHERE

An aphanitic rock containing about 30% calcium-rich plagioclase feldspar, 55% pyroxene, and 15% olivine.

BASALT

Fine-grained mafic rock; most common extrusive igneous rock.

BASALT

Ferromagnesian silicate, belongs to mica family, sheet silicate with cleavage in one direction

BIOTITE

What type if volcano/volcanic region is Mount St. Helens (Cascade Range)?

CONVERGENT PLATE BOUNDARY

What type of volcano/volcanic region are the Aleutian Islands (Alaska)?

CONVERGENT PLATE BOUNDARY

Rudy and sapphire are two varieties of this same mineral

CORUNDUM

Aphanitic felsic rock that is often pinkish in color.

RHYOLITE

Primary constituent in limestone

CALCITE

____________, a popular natural philosophy of the seventeenth and early eighteenth centuries, was based on a firm belief in a very short geologic history of Earth.

CATASTROPHISM

Small, steep-sided volcano composed of vesicular, pyroclastic material that was mainly produced by a single, short-lived eruptive event.

CINDER CONE

Large, nearly symmetrical volcano with gently sloping flanks and a steep summit, composed of altering layers of pyroclastic material and lava flows of andestic composition.

COMPOSITE VOLCANO (STRATAVOLCANO)

Put these features of the ocean floor in order from shallowest to deepest.

CONTINENTAL SHELF, CONTINENTAL SLOPE, CONTINENTAL RISE, ABYSSAL PLAIN, DEEP-OCEAN TRENCH

________ refers to the removal and isolation of early-formed mineral grains that can cause the composition of the remaining magma to change.

CRYSTAL SETTLING

A vertical wall-like feature a few meters wide and hundreds of meters long.

DIKE

Phaneritic rock with the same mineral composition as andesite.

DIORITE

What type if volcano/volcanic region is Iceland?

DIVERGENT PLATE BOUNDARY

What type of volcano/volcanic region is Mount Kilimanjaro (East African Rift Zone)?

DIVERGENT PLATE BOUNDARY

What are the two energy sources that drive the Earth system?

EARTH'S INTERIOR AND THE SUN

What is the least massive of the fundamental atomic particles?

ELECTRONS

Are felsic magmas or mafic magmas more viscous?

FELSIC

What type of lava are violent eruptions associated with?

FELSIC

Which type of lava has the highest gas content?

FELSIC (RHYOLITIC)

Partial melting of intermediate rocks tends to yield what kind of magma?

FELSIC MAGMA

Rank the four major compositional groups of igneous rocks from highest silica content to lowest silica content.

FELSIC, INTERMEDIATE, MAFIC, ULTRAMAFIC

The Columbian Plateau in Washington and Oregan is _______

FLOOD BASALT PLATEAU

Coarse-grained rock dominated by pyroxene and plagioclase feldspar.

GABBRO

A sulfide that is an ore of lead

GALENA

Which of the Earth's spheres is the largest?

GEOSPHERE

What was found in 300 million year old rocks in South America, Africa, India, Antarctica and Australia that provided evidence for Wegener's hypothesis about continental drift?

GLACIAL STRIATIONS

Texture results when magma cools too fast for mineral crystals to form (texture of obsidian)?

GLASSY

A phaneritic rock containing about 20% quartz, 40% potassium feldspar, 20% sodium-rich plagioclase feldspar, a few percent muscovite, and the remainder dark silicate

GRANITE

Phaneritic rock containing less than 25% of dark minerals; most common intrusive igneous rock.

GRANITE

Both slab pull and ridge push are driven by what?

GRAVITY

Evaporite containing an anion (negative ion) of chlorine

HALITE

What happens as magma rises?

HEAT ACCUMULATES AT THE BASE OF THE CONTINENTAL CRUST LEADING TO PARTIAL MELTING OF THE CRUST.

What is convection in the mantle powered by?

HEAT ESCAPING FROM DEEP WITHIN EARTH'S INTERIOR

Important ore of iron sometimes used as red pigment

HEMATITE

Ferromagnesian, double chain silicate exhibiting two planes of cleavage at 60 degrees and 120 degrees, often forms elongated crystals

HORNBLENDE

What happens during decompression melting?

HOT MANTLE RISES, AND PRESSURE DECREASES ENABLING THE MANTLE ROCK TO MELT AND FORM MAGMA

Many major geologic features are attributed to what?

INTERACTIONS BETWEEN PLATES

What type of volcano/volcanic region are the Hawaiian Islands?

INTERPLATE VOLCANISM (HOT SPOTS)

What type of volcano/volcanic region is the Columbia Plateau?

INTRAPLATE VOLCANISM

Pockets of magma can be formed by the melting of deep continental crust heated by the intrusion of other magmas. Which of the following correctly describes this process?

INTRUSION OF BASALTIC MAGMA CAUSES DEEP CRUSTAL ROCKS TO MELT, PRODUCING ANDESTIC AND RHYOLITIC MAGMAS

What happens to plagioclase feldspar as magma cools (temperature decrease)?

IT BECOMES MORE SODIUM RICH AND LESS CALCIUM RICH.

What happens to the remaining melt as magma cools and crystallizes?

IT BECOMES RICH IN SILICA.

What is the main reason for the elevated position of the mid-ocean ride?

IT IS HOT, AND THEREFORE LESS DENSE THAN THE COOLER ROCKS SURROUNDING IT.

A dome-shaped mountainous structure flanked by upturned layers of sedimentary rock.

LACCOLITH

The ____________, which form Earth's rigid outer layer, consist of the entire crust and the uppermost part of the mantle.

LITHOSPHERE

Which type of lava is most likely to result in an effusive eruption?

MAFIC

What type of lava is the hottest and most viscous?

MAFIC (BASALTIC)

What type of minerals form mineral groups that exhibit a range of composition between two end members?

MANY SILICATE MINERALS

What fossils were found in Africa and South America providing evidence for continental drift?

MESOSAURUS, A FRESHWATER REPTILE

Which mineral family peels off in sheets/layers?

MICA

What broad elevated feature forms a continuous belt that winds around the Earth like the seam on a baseball?

MID-OCEAN RIDGE

What is the "melt" of a magma composed of?

MOBILE SILICON, OXYGEN, ALUMINUM, POTASSIUM, CALCIUM, SODIUM, IRON AND MAGNESIUM IONS

Nonferromagnesian silicate, belongs to mica family, sheet silicate with cleavage in one direction

MUSCOVITE

Texture contains a matrix of fine crystals surrounding phenocrysts.

PORPHYRITIC

Does an electrically neutral atom have to have equal numbers of protons and neutrons?

NO

Is Los Angeles moving southwest relative to the North American plate?

NO

Is a volcano a threat only when it is erupting?

NO

Which on is less dense and lighter in color: ferromagnesian or nonferromagnesian?

NONFEROMAGNESIAN

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

NORMAL AND REVERSED MAGNETIZED STRIPS ROUGHLY PARALLEL TO THE RIDGE.

What eventually subducts as it ages and becomes denser than the underlying asthenosphere?

OCEANIC LITHOSPHERE

Which type of oceanic lithosphere subducts at a steeper angle: older or younger?

OLDER

Ferromagnesian silicate made up of independent silicon tetrahedrons linked by iron or magnesium ions, does not exhibit cleavage, conchoidal fracture, glassy luster, typically found in basalt

OLIVINE

What mineral is the first to crystallize in a basaltic magma?

OLIVINE

What mineral would you expect to see as a phenocryst in a porphyritic basalt?

OLIVINE

Where are most transform faults found?

ON THE OCEAN FLOOR

Orthoclase and plagioclase feldspar are very similar. What is an effective way to distinguish between the two?

ONLY PLAGIOCLASE EXHIBITS STRITIONS ON CLEAVED SURFACES.

What type of texture suggests two stages of cooling: a early stage of slow cooling and a subsequent stage of faster cooling?

PORPHYRITIC

Which mineral gives some granites a pinkish color?

POTASSIUM FELDSPAR

The _________ division of the geologic time scale makes up over 88% of geologic time.

PRECAMBRIAN

Light-colored extrusive igneous rock with vesicular texture.

PUMICE

Texture characterized by rock fragments welded together.

PYROCLASTIC

What poses the greatest threat to humans who live in the vicinity of an active volcano?

PYROCLASTIC FLOWS

What type of lava resembles a twisted or ropey texture?

PAHOEHOE LAVA

What is the name of the late Paleozoic supercontinent?

PANGEA

A phaneritic rock made mainly of olivine and pyroxene, with lesser amounts of calcium-rich plagioclase feldspar

PERIDOTITE

What is the most constituent of the upper mantle?

PERIDOTITE

Texture that is coarse-grained with crystals of roughly equal size.

PHANERITIC

What is the eon, era, period and epoch in which we live?

PHANEROZOIC, CENOZOIC, QUATERNARY, HOLOCENE

What type of lava occurs along divergent plate boundaries on the ocean floor?

PILLOW LAVA

Nonferromagnesian silicate, second most abundant mineral in the continental crust, composed entirely of silicon and oxygen in a 3D framework, hard, does not exhibit cleavage, found in a variety of colors

QUARTZ

What is the last mineral to crystallize from a basaltic magma?

QUARTZ

What are some examples of minerals?

QUARTZ, GLACIAL ICE, GOLD NUGGET, RUBY

Very broad, slightly dome shaped volcano with gently sloping flanks, composed mainly of basaltic lava flows.

SHIELD VOLCANO

What is the fundamental building block of all silicate minerals?

SILICON-OXYGEN TETRAHEDRON

A relatively thin layer of basalt sandwiched between horizontal layers of sedimentary rocks exposed along the walls of river valleys.

SILL

Why did Wegener suspect the continents were once joined?

SIMILARITIES BETWEEN COASTLINES ON OPPOSITE SIDES OF THE ATLANTIC

A huge expanse of granitic rock forming a mountainous terrain tens of kilometers wide.

STOCK

What causes the lithosphere to break?

STRESS

What happens during dehydration?

SUBDUCTING PLATE IS SATURATED WITH WATER, AND WATER IS SQUEEZED OUT MIXING WITH THE MANTLE. MELTING POINTS LOWER ALLOWING FOR PARTIAL MELTING OF MANTLE MATERIAL.

What results in deep-ocean trenches?

SUBDUCTION

Cell phones are often recycled to collect gold and other metals from them. This is profitable because...

THE DEMAND FOR THE PRECIOUS METAL HAS INCREASED, AND TECHNOLOGICAL ADVANCES ALLOW THE METALS TO BE EXTRACTED MORE EFFICIENTLY.

What minerals from cooling magma have the lowest silica content and highest melting points?

THE FIRST MINERALS

Earth's geologic processes only involve...

THE GEOSPHERE

Oil residing in the tiny pore spaces of shale was once considered to have no economic value. Today, oil is commonly extracted from these shales. What changed?

TECHNOLOGICAL ADVANCES IN DRILLING AND FRACKING HAVE MADE THE EXRACTION OF THE OIL MORE EFFIECIENT AND PROFITABLE.

What two characteristics are used to classify igneous rock?

TEXTURE AND MATERIAL COMPOSITION

What is the ultimate goal of atomic bonding?

THE ATOMS' OUTER SHELLS AIM TO CONTAIN 8 VALENCE ELECTONS

The Atlantic ocean is relatively younger with its formation associated with...

THE BREAKUP OF PANGEA

What winds through all major ocean basins and is the longest topographic feature on Earth's surface?

THE MID-OCEAN RIDGE

Where does new oceanic crust and lithosphere form at divergent boundaries by submarine eruptions and intrusions of basaltic magma?

THE MID-OCEAN RIDGE

Earth's magnetic field is generated by

THE MOVEMENT OF LIQUID METALLIC IRON WITHIN THE OUTER CORE

What theory states that our Solar System evolved from a giant cloud of gas and dust in the Milky Way?

THE NEBULAR THEORY

What is an example of an active continental-continental collision?

THE NORTHWARD MOVEMENT OF INDIA INTO EURASIA

What determines the identity of an element?

THE NUMBER OF PROTONS IN THE NUCLEUS

What is the only liquid layer of Earth's interior structure?

THE OUTER CORE

How does the plate tectonic theory explain the Ring of Fire around the Pacific Ocean Basin?

THE PACIFIC PLATE IS SUBDUCTING UNDERNEATH OTHER LITHOSPHERIC PLATES AT CONVERGENT PLATE BOUNDARIES PRODUCING VOLCANIC ISLAND ARCS AND CONTINENTAL VOLCANIC ARCS.

What is the most common mineral group?

THE SILICATES

What are the two categories into which the largest features of the continents can be grouped?

THE STABLE INTERIOR AND MOUNTAIN BELTS

Most of our understanding of Earth's interior comes from ___________.

THE STUDY OF SEISMIC WAVES

How do transform fault provide information about the direction of the plate motion?

THEY ARE ALIGNED PERPENDICULAR TO THE DIRECTION OF SPREADING

What accurately describes the volcanoes of the Hawaiian Islands?

THEY ARE FED BY A LONG LIVED HOT SPOT BELOW THE PACIFIC LITHOSPHERE PLATE.

James Hutton was a proponent of _________ which is often paraphrased as "The present is the key to the past".

UNIFORMITARIANISM

Amythest is a mineral __________ of quartz, which is a mineral __________.

VARIETY, SPECIES

Texture has openings produced by escaping gases.

VESICULAR

What are the most abundant gases in most magmas?

WATER VAPOR AND CARBON DIOXIDE

How are most clays produced?

WEATHERING OF OTHER SILICATE MINERALS

Why was continental drift mainly rejected?

WEGENER COULD NOT IDENTIFY A MECHANISM.

Are covalent bonds between silicon and oxygen stronger than ionic bonds that hold together one silicate structure to the next?

YES

Is the modern-day Red Sea a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate?

YES