GEOL 1001 Exam 2

Which site has the lowest hazard for pyroclastic eruptions?

1, the suburbs of Tacoma

Which of the numbers on this figure indicates typical continental conditions (regional metamorphism)?

2

Which of the numbered features is a pyroclastic column?

3

Which location on this diagram would most likely record hot conditions deep within the continental crust?

4

On this figure of Bowen's Reaction Series, which mineral would crystallize last from magma?

4, K-feldspar

Which letter in this classification table indicates the position of granite?

A

In what site on this figure would you expect high pressure/low temperature metamorphism?

A and B

Which of the letters shown on this figure would most likely have mafic (basalt) magmas?

A and C

What is the difference between a joint and a fault?

A fault displaces the rocks on one side relative to another.

The angular clasts typical of breccia indicate what about the distance of transport?

A short distance transport.

Which of the following does NOT help define layers in some sedimentary rocks?

All of these are ways that can define layers in sedimentary rocks.

The main source of heat energy for the Earth's interior is a direct result of

Alpha decay, which is an unstable atom losing 2 protons and 2 neutrons

Which of the letters shown on this figure would most likely include some intermediate to felsic magmas?

B, D, and E

What type of rock is shown in this photograph?

Breccia

At which of the sites shown in this figure would melting probably be caused by introduction of water into hot rocks?

C

Changing conditions from points ____________ would result in decompression melting.

C to B

Changing conditions from points ______________ would result in decompression melting.

C to B

The igneous rocks shown in this photograph are forming

Columnar Joints

Melting in the mantle is a result of

Decompression

For the letters on this figure, choose the likely cause of melting for Site C.

Decompression melting as the mantle rises

Which of the following is NOT a factor that affects the viscosity of magma?

Depth

The igneous feature shown in this figure is a

Dike

If the view is looking north, in what direction were the rocks shortened to form the fold and the cleavage?

East-west

An igneous rock that solidifies on Earth's surface is called a(n)

Extrusive Rock

Which of the following causes magma to be less viscous?

Fewer silicate chains in the magma

Which of the following changes in conditions could represent melting of continental crust from the introduction of a mafic magma?

From A to B

Which of the following changes in conditions would cause melting of a solid rock?

From A to B

Which of the following changes in conditions would represent heating during burial?

From A to C

Based on the image and your knowledge of metamorphic minerals, which of the following is true?

Garnet is diagnostic of moderate- to high-grade metamorphic conditions.

Continental rifts have a diverse suite of igneous rocks associated with them because melting occurs

In the mantle and in the crust

An igneous rock that solidifies below the surface is called a(n)

Intrusive Rock

Which of the following igneous rocks has a texture consistent with a magma that cooled and solidified slowly at first, followed by more rapid cooling?

Large, early formed crystals surrounded by smaller, late formed crystals

Hot spots in oceanic settings typically produce

Lines or clusters of volcanic islands

Which of the magma systems shown is likely to contain mostly basalt?

Locations A and B only

For the letters on this figure, choose the likely cause of melting for Site D.

Melting by adding water

For the letters on this figure, choose the likely cause of melting for Site E.

Melting by adding water

Rocks of the continental crust contain different minerals and each mineral has its own melting point. If the minerals with the lowest melting temperatures are the only ones melted, this is referred to as

Partial Melting

Which of the following rock types requires dissolved gas in the magma?

Pumice

The main cause of melting along subduction zones is the

Release of water from the subducting plate

The igneous feature shown in this figure is a

Sill

Which of the following characteristics are NOT used to classify and name clastic sediments?

The climate in which the clasts are produced.

How would the force and stress on the wooden pillar in this figure change if the stone weight were the same size but the wooden pillar were narrower?

The force would remain the same, but the amount of stress would increase.

What does this texture indicate about the formation of this rock?

The magma formed some crystals before rising closer to the surface and solidifying

Coarsely crystalline igneous textures indicate that

The rock cooled slowly

What can you infer from this contact between an overlying conglomerate and underlying sandstone?

There was an abrupt event, such as a flood.

Which of the following is NOT true about shield volcanoes in the landscape?

They are large mountains with steep slopes

Which of the following is a common characteristic of carbonate rocks?

They commonly have a dissolved appearance.

The cross beds shown here indicate what about the environment the sandstone was deposited in?

Water/wind flowed from right to left.

A volcanic eruption occurring beneath an ice sheet is likely to cause

a hazardous flood

What type of volcanic eruption is shown in this photograph?

a pyroclastic column

If a rock is poorly sorted, this means the rock contains

a wide range in the size of clasts.

What is the typical setting for fold and thrust belts?

associated with convergent plate boundaries

The largest volcanic eruptions on Earth are floods of

basalt magma

What types of rocks would be most common in the volcano shown in this photograph?

basalt mostly formed in lava flows

Eruptions of scoria cones are commonly associated with

basaltic lava flows and lava fountains

Which of the rock layers in this figure was most likely deposited in a shoreline environment?

both of the tan sandstones

Huge, circular depressions from which volcanoes erupt are called

calderas

The most dangerous type of volcano is a

composite volcano

What type of rock is shown in this photograph?

conglomerate

The typical shape of most volcanoes, including the one shown here, is

conical

Which of the following environments would most likely form limestone?

coral reef at C

In ____________________________________, magma cools at a slow rate, allowing the formation of _______________________________.

deep magma chambers; coarse-grained rocks

A very well-sorted sandstone with large-scale cross-bedding indicates the sand was likely

deposited by the wind in dunes.

Which of the following features is probably the same age as fault 2?

deposits along the fault

Some volcanic ash rises vertically in an ________________________________, cools before accumulating on the surface, and forms deposits that are __________________.

eruption column; nonwelded

Which of the following best describes the temperature of materials typically erupted from volcanoes?

extremely hot

The most common clastic sedimentary rocks are made of the clasts that are

fine grained (smaller than sand).

What type of stress could form the fault in this figure?

horizontal compression

In what direction were the rocks in the center of this cross section shortened?

in a horizontal direction

In what environments does high pressure/low temperature metamorphism occur?

in a subduction zone or accretionary prism

What type of deformation is shown in this photograph?

internal strain of the rock

Steep and unstable slopes can produce _____________________________, forming ___________________________.

landslides and mudflows; volcanic breccia

Magma erupted on the surface can form a __________________________ that cools quickly, resulting in ______________________________.

lava flow; volcanic glass

Sedimentary clasts are

loose fragments of rocks and minerals.

Magma can partially crystallize at depth and then rise to shallow depths where the remaining magma solidifies. The early-formed crystals are _______________ and the texture is ________________.

phenocrysts; porphyritic

Some volcanic ash forms _________________________________ that accumulate while hot and can become ___________________ to some extent.

pyroclastic flows; welded

What type of metamorphism would occur in this setting?

regional metamorphism

What type of deformation is shown in this photograph?

rotation

Which of the following is the most used sedimentary resource?

sand and gravel

This volcano is relatively small and composed of volcanic cinders. What kind of volcano is it?

scoria cone

Which of the following lists the four types of volcanoes shaped like hills and mountains?

scoria cone, shield, composite, dome

Magma that cools in ______________________________ has a relatively short time to cool and so forms __________________________, but not volcanic glass.

shallow magma chambers; fine-grained rocks

Volcanic domes commonly are partially destroyed when

steep parts of the dome collapse and cause small pyroclastic flows

Which of the following situations would result in angular clasts?

steep slopes in a mountain

The typical form for a composite volcano is a

steep-sided cone

Sorting describes

the size range of clasts in sediment.

The advance of the sea across a region is known as a

transgression

Volcanic domes grow from lava being injected into the interior of mounds of cooled lava and from the breaking out and moving down the flanks of

viscous lava flows

In ___________________________________________very large crystals can grow, forming ________________.

water-rich parts of the magma; pegmatite