Chapter 9: Understanding Landscapes

Match the letter with the appropriate feature indicated on the image by the arrow. (a, b, c)

A - A bedding plane separating one bed of rock from another B - Vertical fracture in the rock C - Slope composed of loose rock material

Igneous

A volcano erupts lava, which then cools and solidifies.

Felsic

Abundant magnesium and iron; dark colored

Intermediate

Abundant quartz and feldspar; light colored

Gneiss

Alternating dark and light bands; a banded, compositional foliation

Horizontal lines can be followed around the cliff.

Bedding of sedimentary rock layers can be seen in the cliff.

Weathering

Breaking down of rocks either mechanically or chemically

______ are formed in landscapes when the parent material rocks are very hard and resist erosion. Multiple select question. Cliffs Peaks Steep slopes Gentle slopes Valleys

Cliffs Peaks Steep slopes

_______ are examples of features readily identifiable through simple visual observation in many landscapes. Multiple select question. Cliffs and slopes Sedimentary bedding planes Loose pieces of rock Numeric ages of rocks Rock colors Fractures

Cliffs and slopes Sedimentary bedding planes Loose pieces of rock Rock colors Fractures

Which of these approaches would be helpful strategies for observing landscapes? Multiple select question. Compare different parts of the landscape to each other. Spend most of your time describing the tiny details. Focus on one part of the landscape at a time. Focus on one geologic feature at a time. Ignore geologic features entirely. Draw a sketch to capture main features.

Compare different parts of the landscape to each other. Focus on one part of the landscape at a time. Focus on one geologic feature at a time. Draw a sketch to capture main features.

Which of these approaches would be helpful strategies for observing landscapes? Multiple select question. Draw a sketch to capture main features. Focus on one part of the landscape at a time. Compare different parts of the landscape to each other. Ignore geologic features entirely. Spend most of your time describing the tiny details. Focus on one geologic feature at a time.

Draw a sketch to capture main features. Focus on one part of the landscape at a time. Compare different parts of the landscape to each other. Focus on one geologic feature at a time.

Shale

Easily eroded, thinly bedded rock that forms soft slopes covered by small, loose chips derived from weathering

True or false: In sedimentary rocks, rock layers are deposited and always remain in horizontal layers. True false question. True False

False

Granite

Felsic

Marble

Fine-grained to coarse-grained calcite; metamorphosed limestone

Coal

Formed from buried and compacted wood and plant material

Iron Formation

Formed from precipitation of seawater early in Earth history; used in steel production

Gypsum

Formed through evaporation of seawater; used in wallboard

Chert

Formed when silica-rich plankton accumulates on the ocean floor

The vertical lines highlighted are what type of feature? Multiple choice question. Bedding Loose rock Slopes Fractures

Fractures

___ is a coarse-grained intrusive igneous rock composed predominantly of feldspar and quartz.

Granite

volcanic rock

Has layers, as well as fractures that are perpendicular to the layers; may be gray, green, brown, tan, or cream

______ rocks form from the cooling of magma or lava. Multiple choice question. Metamorphic Igneous Sedimentary

Igneous

Diorite

Intermediate

basaltic lava flow

Is the most common type of volcanic rock; spreads out easily and forms a dark rock; columnar joints common

granite

Is usually fractured and makes up most of the continental crust

Sandstone

Layers that differ in color, grain size, or composition because they were deposited during changing environmental conditions

Marble

Limestone

Sedimentary

Loose sediment on Earth's surface is deposited by moving water, air, or ice.

Basalt

Mafic

Which of the following rock cycle processes usually occurs at great depth, in the lower crust or the mantle? Multiple choice question. Melting Lithification Erosion Transportation

Melting

Which of the following rock cycle processes usually occurs at great depth, in the lower crust or the mantle? Multiple choice question. Melting Lithification Transportation Erosion

Melting

Which of the following type of rock is formed by the solid-state alteration of a previously existing rock by heating, pressure, and/or fluid chemistry? Multiple choice question. Igneous Metamorphic Sedimentary

Metamorphic

Which of the following type of rock is formed by the solid-state alteration of a previously existing rock by heating, pressure, and/or fluid chemistry? Multiple choice question. Sedimentary Igneous Metamorphic

Metamorphic

___ rocks are formed by changing previously existing rocks through increases in temperature or pressure, deformation, or chemical reactions.

Metamorphic or metamorphosed

Schist

Mica crystals that are large enough to see with the naked eye

Mafic/Ultramafic

Mineral content in between; color moderate

Transportation

Moving pieces of rock by wind, ice, or water

What type of sedimentary rocks commonly contains minerals precipitated from solution as water evaporates or materials formed through biological activity such as making shells or other hard parts? Multiple choice question. Clastic Nonclastic

Nonclastic

Deposition

Occurs when the energy of the transported materials decrease

Metamorphic

Previously existing rocks are changed by temperature, pressure, or deformation.

Lithification

Process of sediment turning into rock

Different interpretations may be made regarding the properties of rock units 2, 4, and 6. Match the rock unit with its appropriate interpretation.

Rock Unit 2 - The slope indicates that the rock is somewhat easily weathered. Rock Unit 4 - The rock forms a steep cliff because it is resistant to weathering. Rock Unit 6 - This is composed of loose rock that has weathered from the rock layers above.

Edges of some rock layers form cliffs, whereas others form slopes.

Rock layers have different resistances to weathering processes.

_____ are made up of _____. Multiple choice question. Rocks; minerals Minerals; rocks

Rocks; minerals

Quartzite

Sandstone

______ rocks can be metamorphosed by changes in temperature or pressure. Multiple select question. Sedimentary Igneous Metamorphic

Sedimentary Igneous Metamorphic

Slate and Gneiss

Shale

Phyllite

Sheen present due to microscopic mica minerals

_____ are the most common mineral group in Earth's crust. Multiple choice question. Salts Carbonates Oxides Sulfides Silicates

Silicates

A slope at the base of the cliff is composed of loose pieces of rock.

The main cliff has weathered, causing loose rock to fall to the bottom and accumulate.

Vertical cracks extend back into the rock.

The rock has fractured, and these breaks in the rock are cutting vertically across layers.

As sediment is buried by material above it, compaction starts to occur. Identify some of the effects of this compaction on the sediment. Multiple select question. The sediment becomes more dense packed. Clay particle alignment becomes randomized. Pore space is increased. Excess water is expelled. Clasts get pushed together.

The sediment becomes more dense packed. Excess water is expelled. Clasts get pushed together.

Quartzite

Tightly merged quartz crystals; metamorphosed sandstone

True or false: Metamorphism may occur without deformation. True false question.

True

Uplift

Upward movement of underground rocks to the surface

The three primary forces that deposit sediments, which may become sedimentary rocks, are water, ___ , and ___

air/wind; ice/glaciers

Layers within sedimentary rock are called ______. Multiple choice question. fractures sediment beds slopes

beds

All of the following are examples of nonclastic sedimentary rocks, except ______. Multiple choice question. breccia coal rock salt iron formation

breccia

Crystals in coarse-grained igneous rocks normally _____ be seen with the unaided eye. Multiple choice question. can cannot

can

Nonclastic sedimentary rocks are commonly formed by ______ processes. Multiple choice question. chemical and biological chemical biological

chemical and biolgical

The grain size of ______ igneous rocks is larger than 1 millimeter. More commonly, this grain size is described as being large enough to see with the unaided eye. Multiple choice question. vesicular fine-grained coarse-grained

coarse-grained

Metamorphism involves the processes of ______. Multiple select question. deformation erosion pressure heat weathering

deformation pressure heat

In rock subjected to heat and pressure, folding, faulting, and shearing may simply be called ______, but if mineralogical or rock texture changes take place, the process is called ______. Multiple choice question. rotation; fracture deformation; displacement metamorphism; melting deformation; metamorphism

deformation; metamorphism

True or false: Only one strategy is employed by geologists to observe a landscape. True false question. True False

false Reason: There are many helpful strategies to help a geologist make observations about a landscape, including focusing on individual features, noticing layers and colors of rocks, and sketching major components.

Layers in sedimentary rock can be _____. Multiple select question. invisible folded tilted horizontal

folded tilted horizontal

Physical geographers and geologists who study the spatial pattern, form, and evolution of landforms to understand landscapes are ______. Multiple choice question. landscapologists physicists geomorphologists

geomorphologists

A coarse-grained intrusive igneous rock composed mostly of feldspar and quartz is called ______. Multiple choice question. granite basalt gabbro andesite rhyolite

granite

The image shows the igneous rock ______, which makes up the bulk of the continental crust. Multiple choice question. sandstone granite basalt

granite

Besides liquid water, the other two transportation agents of sediments are ___ and ___. Gravity also plays a role in moving sediments.

ice/glaciers; wind/air

Rock that forms from magma, lava, or ash is ___ rock. This type of rock may form when volcanoes erupt ash and lava or when molten rock crystallizes in magma chambers at depth.

igneous

This image is a landscape of ______, a type of sedimentary rock. (image: Guadalupe Mtns, TX) Multiple choice question. limestone sandstone shale

limestone

Sedimentary rocks are formed when loose sediment undergoes the process of ___, which involves the compaction and cementation of materials.

lithification or diagenesis

Melting of rocks at great depth produces ___.

magma

If rock is exposed to enough heat after metamorphism, it will eventually ______ into magma. Multiple choice question. solidify crystallize weather melt

melt

If rock is exposed to enough heat after metamorphism, it will eventually ______ into magma. Multiple choice question. weather melt solidify crystallize

melt

All of the following describe processes involved in the formation of sedimentary rock, except ______. Multiple choice question. compaction cementation lithification melting

melting

All of the following describe processes involved in the formation of sedimentary rock, except ______. Multiple choice question. lithification melting compaction cementation

melting

Some ___ rocks form layers that are platy and jagged outcrops, as in the attached image.

metamorphic or foliated

Changing a rock by heat, pressure, or deformation is called

metamorphism

Changing a rock by heat, pressure, or deformation is called ___

metamorphism

Although a rock may appear homogeneous, most are composed of various

minerals or crystals

Compaction causes sediment to become ______. Multiple select question. more porous less dense more compact more dense

more compact more dense

Lava is molten rock that cools ______. Multiple choice question. on Earth's surface underground

on Earth's surface

Temperature and pressure changes can result in ______ weathering. Multiple choice question. physical chemical

physical

The two types of weathering are ______ and ______. Multiple select question. physical biological ecological chemical

physical chemical

Loose materials called ______ are formed by the breaking down and wearing away of rocks in the landscape. Multiple choice question. soil sludge dirt sediment

sediment

When rocks break down and wear away, the material that comes loose is called

sediment

The three agents of ______ that deposit their load when their energy decreases are ice, wind, and water. Multiple choice question. gravity lithification weathering sediment transportation

sediment transportation

Clastic sedimentary rocks are classified primarily based on the size and ______ of their clasts. Multiple choice question. color age shape

shape

Clastic sedimentary rocks are classified primarily based on the size and ______ of their clasts. Multiple choice question. color shape age

shape

Metamorphic rocks are recognized in the landscape by their ______.

shiny luster mineral-filled fractures (i.e., veins)

More than 90% of the minerals in Earth's crust belong to the ______ family. Multiple choice question. carbonate sulfide silicate

silicate

The ___ mineral group is based on the compound (SiO4)-4; the ___ minerals do not contain silicon.

silicate; nonsilicate

Distinguish silicate from nonsilicate minerals by matching each group to its description.

silicates <-- Based on (SiO4)^-4 nonsilicates <-- Does not contain silicon

Clastic sedimentary rocks are composed of rock and mineral pieces; we classify them according to the ___ and shape of the clasts.

size

Geomorphologists study ______. Multiple choice question. the evolution of landforms sedimentary rocks and processes fossils

the evolution of landforms

Parent rocks that are soft tend to erode more easily, forming ______ in landscapes. Multiple select question. cliffs steep slopes valleys peaks gentle slopes

valleys gentle slopes

The primary forces that act to deposit sediments, which may eventually become sedimentary rocks, are ______. Multiple select question. water elevation wind ice tides

water wind ice