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Ralph S. (Ralph Stockman) Tarr.

A laboratory manual for physical and commercial geography online

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perfectly developed. More recently there has* been a slight elevation of the region, reju-
venating the streams. Over the hard crystalline rock lies a thick mantle of residual soil,
giving opportunity for agricultural development. The region is one which was occupied and
settled very early in the history of the country. (Text-book, p. 307.)

On your contour map of the United States plot the outline of the Piedmont Area as shown
on the diagram map. Why is the Piedmont Area most important in the Southern States ?



What province does it adjoin on the east?

What line separates the two provinces?

What important crop is raised on both the Piedmont and the Coastal Plain provinces ?

By (approximately) how much do these two provinces differ in general

elevation?

What similarity of topography have they?

__. What is the rock structure which underlies each ?



Color in lightly and uniformly, using red pencil, the area of the Piedmont Province as you
have outlined it on your United States map. Fill in the proper legend square • and mark it
Appalachian Piedmont.



173



Study of a Locate the position of the Farmville (Va.) sheet on your United States map and outline

typical sec- its area with ink. Letter in the name of the sheet.

tion of the What is the nature of the topography shown on the Farmville sheet ?

Piedmont r r J

Area.



What regi on

previously studied does it most resemble?

How do you account for this similarity?

Why should this region, which is so like a plain, be called an old mountain region ?



The topography of the Farmville sheet was once as rugged as that of the Mt. Mitchell sheet.
What can you say regarding the amount of time which must have elapsed since it had such a

topography ?



State why the Piedmont Area is called a peneplain.



What is a monadnock ? (Text-book, p. 298.)



What example of a monadnock do you find on the Farmville sheet?

How many feet does the Appomattox River descend within the area

of the map ? .Why has it such a meandering course ?



174







: Why are the

small tributary streams eroding their valleys ?

Human What is the pattern of the roads in this region?

occupation.



Does it coincide with that of the drainage lines ? Does it coincide with the

divides? _._ Why?







What indication do the

number, size, and location of the towns (individual houses are not shown on this sheet) and

the number of the railroads give that this is a rich agricultural region?



Write a short paragraph describing the nature of the country, with respect to topography,
agriculture, and drainage conditions, that you would see looking from an elevated point, like
Willis Mountain.



175



t



Materials. For Each Student.

Colored pencils.



XLL— THE LAURENTIAN HIGHLANDS



The contour map of the United States. The Lake Placid (N.Y.) sheet.



Purpose. To study the topography of the old crystalline mountam areas known as the Laurentian High-

lands; and the utilization of the Adirondack portion of these as a vacation and resort country.



Introduc-
tory.



Location
and extent
of the
Laurentian
Highlands.



To the north of the eastern part of the United States is found a great area of crystalline
rock, known as the Laurentian Highlands, which is considered to be made up of some of the
oldest rocks of the earth's crust. The Lake Superior Highlands and the Adirondack Mountains
are outlying masses of these Laurentian Highlands, which at these points project into the
territory of the United States. (Text-book, pp. 107 and 302.)

Outline, on your contour map of the United States, the areas of the Laurentian Highlands,
as shown on the diagram map.

What is the relative importance of the Laurentian Highlands in the United States with

respect to the amount of territory they comprise ?



Why does their location further lessen their im-



portance ?



What well-known city is situated in the Lake Superior Highland region ?
To what conditions does this city owe its importance?



Why was Lake Champlain, in the

eastern part of the Adirondacks, so important in the early history of the United States ?



On your United States map color in with red pencil (using circles as indicated on the
legend square of the diagram map) the areas of the Laurentian Highlands in the United States
as you have outlined them. Fill in the proper legend square.



177



Study of a Locate the position of the Lake Placid (N.Y.) sheet on your United States map, and out-

section of jj ne jt s area with ink. Letter in the name of the sheet. What is the shape and arrangement



the Adiron
dacks.



of the mountain masses shown on this sheet ?



How do they differ in shape from the Folded

Appalachians ?



From the Crystalline Appalachians?

Which is the highest mountain

shown on this sheet, and what is its elevation?

What is the elevation of several other important peaks?

What do the contour lines show as

to the nature of the outline of the -mountains, — are they sharp and rugged or smooth and

flowing? What does this condition indicate

as to the age of the mountains ?

What is the evidence on this point of the number and

shape of the valleys on the mountain slopes?



How may differences in rock account for the

wide valleys between the mountains ?



What is the elevation of the mountains as

compared to the approximate general elevation of the wide valleys between them?



178



- Do the

mountains appear high or low ? How do you

explain the presence of so many lakes and swamps in a mature mountain region ?



If the swamps were formerly lakes, what must have happened to them since ?



Human What do you observe as to the density and distribution of the settlement of this region ?

occupation.



Why are the roads so comparatively numerous in this mountain region ?







Near what great

centers of population are the Adirondack Mountains ?



What is the bearing of this fact on

its development as a resort region?



What is the attraction of the mountains for city people ?



What recreation and sport do the lakes and rivers afford?

179



Why is there an especially large

settlement around Mirror Lake and Lake Placid ?



Write a short paragraph summarizing the attractions of the Adirondack Mountains as a
resort country.



180



Materials.



Purpose.



Introduc-
tory.



Location
and extent
of the
Rocky
Mountain
province.



XLIL — THE ROCKY MOUNTAINS

For Each Student. — The contour map of the United States. The Saw Tooth (Idaho) sheet. Colored
pencils.

For General Class Use. — A wall map of the United States showing railroads.

To gain an appreciation of the topographic features of the Rocky Mountains, and of the man-
ner in which the presence of ores and open valleys in the mountains has affected their settlement.

The Rocky Mountains constitute the most easterly member of the Western Cordillera, a
general term given to all the mountainous section of the United States which lies, for the most
part, west of the 105th meridian. Because of its physiography, the Western Cordillera, as a
whole, is a sparsely settled region ; but local conditions, in places, attract a comparatively
large population. (Text-book, pp. 106-107, and 314-315.)

On your United States map outline the area of the Rocky Mountain province as shown on
the diagram map.

What is the north-south length of the Rockies?



How do they compare in this respect to the Appalachians?



What other factors



make the Rockies a more complete barrier to travel than the Appalachians ?



By consult-
ing the wall map of the United States, locate and plot on your United States map the route
followed by the transcontinental railroads in crossing the Rockies. As shown by the topog-
raphy on your United States map, what factors determine the location of these routes?



How has the presence of the railroads affected settlement in the Rockies ?



What impor-



181



tant cities are located on these routes ?



Color in, with red pencil (using the angle symbol

shown in the legend square), the province of the Rocky Mountains as you have outlined it on

your map. Fill in the proper legend square and mark it Rocky Mountains.

Study of Locate the position of the Saw-Tooth (Idaho) sheet on your map of the United States,

an area in anc i outline its area with ink. Letter in the name of the sheet,
the Rocky

Mountains. What is the approximate general elevation of this area?



What are the elevations of some of the higher peaks!



What are the ele-
vations of the bottoms of the larger valleys?

As indicated by these conditions, do the indi-
vidual ranges and peaks constitute the mountain uplift, or does the region as a whole ?

By what processes are the lesser ranges and peaks

developed ?



Does the topography of this region indicate young, mature, or old conditions?

Describe the topography of the country as it

would appear to an observer stationed on the summit of Big Peak.



182



What evidence indicative of former glaciation of this region do you note?

.+ In what por-
tion of the map are lakes especially conspicuous?

Where else do very small lakes occur?

What is the significance of the occurrence and location of these smaller lakes?



How might

deposits from glacial streams account for the wide, level-floored valley in the northern part of



this area?



Human Locate the one road of the area which continues unbroken across one of the mountains.

occupation.

How many feet must one climb between Galena and the summit of the divide?

In how many miles? Why has the road in this section

several very sharp turns?

What two sections of the area have invited settlement?



What was the reason for the

settlement in each case?



183



Suggest a reason why the mines in the southeast section are closely
grouped.



What is the probable method of transportation between the Silver Star mine and
the King of the West mine?

About how many square miles of land are available for agriculture in the large valley to

the north? What is the nature and importance of Rocky Mountain

Parks? (See Text-book, p. 95.)



Write a short paragraph summarizing the significance of the Rocky Mountains as a bar-
rier to transportation and travel, and the reasons for their settlement in isolated areas.



184



Materials.
Purpose.

Introduc-
tory.



Location of
the area.



XLIII. — MOUNTAIN GLACIERS AND THE CONTINENTAL DIVIDE

For Each Student. — Contour map of the United States. Chief Mountain (Mont.) sheet.

To study the topography of a mountain region having existing glaciers, and the evidence it
presents of former more extensive glaciation.

The mountain region shown in this sheet has topographic characteristics of a stage
between youth and maturity. The normal topography of weathering and stream erosion has,
however, been modified very much by glacial erosion. The glaciers which exist to-day are
but remnants of former much greater ones, as is indicated by the topography. The region has
a further interest in that it is along the line of the Continental Divide. This map, and those
used in the exercises on the Colorado Plateau and Canyon, and the Yosemite, are commended
for their excellence of topographic expression; they illustrate the possibilities of contour
maps in expressing land forms. (Text-book, pp. 137-139, 141-142.)

Locate the position of the Chief Mountain (Mont.) sheet on your contour map of the United
States, and outline the area with ink. Letter in the name of the sheet.

In what physiographic province is the Chief Mountain region?

What is the latitude of the northern edge of the sheet?



What boundary line does it mark?

Continental Examine the Chief Mountain sheet. What determines the line of the Continental

Divide.

Divide? '_

What is the eventual destination of the precipitation that falls on the eastern side of the

divide? u

On the western side?

What is the effect of the presence of forests on the rate of the run off of rain and snow water
from a land surface?



Why has this area been made a " Forest Beserve" ?



185



Why is the pres-
ence of forests desirable at the headwaters of streams ?



Existing Name the larger glaciers mapped in this area,

glaciers.



What is their general distribution?



On which side of the divide are the greater number ?

What explanation can you offer to account for this fact ?



Which glacier is largest?

What is its length in miles and fractions of a mile ?

Its width? How does this compare with the

dimensions of Alpine glaciers? (See Text-book, p. 137.)



What is the lowest altitude to

which the glaciers descend? How many of the glaciers descend to

about the 7500 foot level ? What reasons can you suggest for this uni-
formity in the altitude of their melting ends?



186



Evidence What provinces of the United States, which you have previously studied, were character-

of former



# g f ea . te L r . ized by the presence of many lakes ?
glaciation. ' . r J



What is the significance of the many lakes in this

region ?

Describe the shape of the depressions occupied by the existing glaciers.



What is a cirque? (See Text-book, p. 142.) ..



Identify other cirques in this region besides those
occupied at present by glaciers.



Make a cross section of the valley of Swiftcurrent Creek (emptying into the Sherburne
Lakes) on a line (N.W.-S.E.) between Point Mt. and Appekunny Mt. Let one division of
the cross-section paper equal 200 feet in the vertical scale. What is the shape of this valley

cross section? ■_



How does it differ from the shape of the cross sections of valleys in the Appalachian Plateau?



What is the significance of a U-shaped valley ?



187



Locate and name other valleys on this sheet

which have similarly shaped valleys.



What are hanging valleys ? (Text-book, p. 142.)



Why are waterfalls present at the mouths of hanging valleys ?



Locate examples of hanging

valleys; for example, in St. Mary River valley.



What is the evidence of the presence of

lakes, cirques, the U-shape of the valley cross sections, and hanging valleys on the question

of the former greater extension of the glaciers ?



188



(



XLIV. — THE COLUMBIA LAVA PLATEAU

Materials. For Each Student. — The contour map of the United States. The Spokane (Wash.-Idaho) sheet.

The Denver (Colo) sheet. Colored pencils.

Purpose. To study the topography and settlement of the Columbia Lava Plateau.

Introduc- The region of the Columbia Lava Plateau is made up of great sheets of lava, which, in a

tory. comparatively recent geological period, welled up from fissures in the earth's crust, and spread

over the country as immense floods of molten rock. Since then the plateau surface has been
much dissected by denudation ; and a thick mantle of residual soil covers large portions of its
area. (Text-book, pp. 125-126.)

Location On your contour map of the United States plot the area of the Columbia Lava Plateau as

and extent

of the area, outlined on the diagram map. What states are partly included in this province ?

i What

range of altitude do you note?

What portion of the province is most plateau-like in its

topography?

• Why is the portion of the province which adjoins the course of the Colum-
bia River most dissected ? r



Color in, with brown pencil (using the symbol indicated in the legend square on the dia-
gram map), the province of the Columbia Lava Plateau. Fill in the proper legend square and
mark it Columbia Lava Plateau.

Study of a Locate the position of the Spokane (Wash.-Idaho) sheet on your map of the United States,

section of and outline its area with ink. Letter in the name of the sheet.

the Colum- What physiographic province borders the Columbia Lava Plateau on the east?

along its What portion of the area mapped on the Spokane

eastern «

margin. sheet is to be included in the Pocky Mountain Province ?

What was the approximate general altitude of this part of the Columbia Lava

Plateau before dissection, as shown on this sheet? What are the

physiographic characteristics of Five Mile Prairie?

189



What physiographic term would you

apply to it? Locate other similar areas.

Are mesas most com-
mon in a region of little or great rainfall ? In

regions of horizontal or of inclined strata?

What does this indicate regarding the position of the strata and the rainfall conditions on the

Columbia Lava Plateau?

Account for the

presence of so many permanent streams in this section of the Columbia Lava Plateau.



Human Is there more agricultural settlement on the level areas, such as the mesa tops, or on the

occupation.

valley slopes? The soil of the Columbia

Lava Plateau is residual, — that is, it is formed by the decay of the lava rocks, and rests
directly on them. Why should there be a greater depth of this soil on the uplands than on

the valley sides? 1



What is the significance of the location of Spokane with reference to.the Spokane Valley
as a highway?



Eemembering that the Great Northern is a transcontinental railroad, what
influence has the location of Spokane had on the course of railroads ? „



190



There is a waterfall

in the Spokane River where its course passes through Spokane. What is the bearing of this

fact on the exact location and growth of Spokane?



Write a short paragraph contrasting and comparing the sites and environs of the cities of
Denver and Spokane.



191







XLV. — THE GREAT BASIN REGION

Materials. For Each Student. — The contour map of the United States. The Granite Range (Nev.)

sheet. Colored pencils.

Purpose. To gain an appreciation of the physical geography of the Great Basin, Region.



Introduc-
tory.



Location
and extent
of the Great
Basin.



The Great Basin is a region of interior drainage. (Text-book, p. 324.) Its area is encom-
passed by more elevated mountain and plateau barriers, and the precipitation of the present
climate is not sufficient in amount to enable the basin to fill up and overflow at some point on
its rim. In recent geological times, however, the climate of the Great Basin Region was
more humid, and a large lake, Lake Bonneville (Text-book, pp. 163-164) occupied a great
extent of its area, the mountain ranges projecting as islands above its level.

A region to the southeast marked " Open Basins " has similar conditions to those of the
Great Basin, except that most of the drainage escapes to the sea.

On your contour map of the United States plot the outline of the area of the Great Basin
as indicated on the diagram map. What state and parts of states does it include within its

limits?

What is the general nature of its



topography ?



What is the most important stream within the Great Basin ?
Where is its source?



Its mouth?

In what respects are the courses of the smaller streams similar

to that of the Humboldt River ?



What is the general trend of the mountain ranges ?



Figure 301 of the Text-book is a map of the extent of the former Lake Bonneville.
Outline its extent, approximately, on your contour map of the United States, using a dotted
line. Mark the area, thus inclosed, Lake Bonneville.



193



Where was the probable region of outflow of former Lake Bonneville, as indicated by the
contour lines on your United States map ?
What approximate proportion of its area does the

present Great Salt Lake occupy ? What does

the location of Great Salt Lake indicate as to the deepest portion of the former Lake Bonne-
ville ? '

Suggest a reason why the main settlement of the Great Basin region centers
about the present lakes within its area.



Color in, with yellow pencil (using ruled lines as indicated in the legend square of the
diagram map), the area of the Great Basin region as you have outlined it on your United
States map. Fill in the proper legend square and mark it Great Basin.

Studv of a Locate the position of the Granite Range (Nev.) sheet on your map of the United States

typical area and outline its area in ink. Letter in the name of the sheet.

within the What three prominent features make up the physiography of this area ?

Great

Basin.

What is the

general trend of the mountain ranges?

The Selenite Range is typical of many of the Basin Ranges. What is the approximate

length of the Selenite Range ? Its elevation ?

How do these dimensions and its isolation compare with ranges of the Rocky Mountain region ?



Where are the sources of the small streams?

Why do they disappear when they reach
the level places?



What becomes of the dissolved material they are carrying ? (Text-book,

pp. 87 and 169.) .

191







Where are such deposits being formed in this area ?



What becomes of the
sediment they carry?

What suggestion does this give as to thexn-igin of the fiats between the
mountain ranges ?



What would be the bearing of the former greater extent of Pyramid

Lake on the question of the origin of these flats ?



Human Why are there no cities within this area ?

occupation.



* What one industry is indicated by a place

name? Why should salt be found in such

a situation? (Text-book, p. 163.)



195







XLVL— THE COLORADO CANYON AND PLATEAU

Materials. For Each Student. — Contour map of the United States. The Bright Angel (Ariz.) sheet. Col-

ored pencils.

Purpose. To study the erosional ivork of a great river, cutting through thick horizontal strata in an

arid plateau region.



Introduc-
tory.



Location
and extent
of the
province.



The Colorado Kiver has its source among, and is fed by, the melting snows of the moun-
tains of the lofty central Rocky Mountains, being formed by the junction of the Green and the
Grand rivers. The river waters are abundantly supplied with sediment by the weathering of
the mountain slopes, yet are not overloaded. Consequently, in flowing across the plateau to
the south and west, the river has been able, by means of its rock tools, to carve the remark-
able canyon which bears its name. The Colorado Plateau Province itself consists of a series
of rock platforms, level in topography and separated one from the other by fault and weather-
ing escarpments. (Text-book, pp. 81-82 and 322-323.)

On your contour map of the United States plot the outline of the area of the Colorado
Plateau as shown on the diagram map.

What states lie partly in this province ?



Colorado Plateau, excluding the Canyon ?



What is its approximate elevation ?

What is the nature of the topography of the



Approximately how many feet does the Colorado River descend between the point of junction
of the Green and Grand rivers and the point where it first touches the Nevada state

boundary line ? About how long is this portion of its course ?

\ How does its average descent per mile compare with that of the

Mississippi below Cairo? (See exercise on Mississippi Flood-plain and Delta Province.)



Why has the Colorado River such great erosive power ? .



197



On your contour map of the United States color in with green pencil (using the symbol

shown in the legend square) the area of the Colorado Plateau. Fill in the proper legend

square and mark it Colorado Plateau.

Study of Locate the position of the Bright Angel sheet and plot the outline of its area on your

the Grand United States map. Letter in the name of the sheet. What is the general direction of slope

Canyon and Q £ ^ e Colorado Plateau as shown by the areas named the Kaibab Plateau to the north of the
adjacent

areas Canyon, and the Coconino Plateau to the south?

. What effect has this had on the course of

small streams on the plateau surface? :

How may these conditions account for the longer slope of the north side of the Grand Canyon
at this point ?



What is the scale of the Bright Angel sheet?

What is the approximate width of the Grand Canyon on a line directly north from Grand

Canyon station? What is the greatest depth of the canyon

shown? How does this width and depth compare with the dimen-
sions of the Niagara Gorge?



What condition of slope is indicated where the contour lines are run together to form a

ribbon of solid brown? ___•_ 1

What kind of rock layers, hard or soft, would be marked by vertical

cliffs? L Account for the isolated monu-
ments, like the Isis Temple, left standing as outliers of the canyon wall.



198



Name various illustrations of stages in the process of formation of such buttes and mesas.



In what kind of rock is the river cutting at present, as indicated by the name of the

inner gorge ? Why is there no alternation


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Online LibraryRalph S. (Ralph Stockman) TarrA laboratory manual for physical and commercial geography → online text (page 9 of 16)