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Brit ish Columbia Forest Serviee . Research Note No. 6681974

, MANUAL .OF

.,LANDFORMS; AND THE1 R INTERPRETATION

..̂ __ FROM A E R I A L PHOTOGRAPHS

' iw~ "-

WITH EMPHASIS ON FOREST LAND MANAGEMENT APPLICATIONS

IN

BRITISH COLUMBIA

by N . Keser

PART I - LANDFORMS

PREFACE

A Landform In te rp re t a t ion Manual is being prepared by Dr. Nuret t in Keser as a r e su l t o f t he Geology-Landform Soi ls courses that he has organised and p resen ted i n s eve ra l Forest Districts throughout Brit ish Columbia s ince 1969.

This i s an advance copy of Part 1 of the proposed manual. Part 2 will follow later i n t h e y e a r and will be wri t ten i n co- operat ion with other resource users . I t will i l l u s t r a t e landform i n t e r p r e t a t i o n f o r forested land management p rac t i ce .

The purpose o f re leas ing a preliminary copy is t o s o l i c i t your ass is tance, as users during the 1974 f i e ld s eason , t o improve upon content and p resen ta t ion be fo re f i na l ed i t i ng and publ ica t ion .

I be l i eve t h i s p ionee r ing t ex t w i l l cont r ibu te much t o our understanding. I commend t h e p r o j e c t t o you and t r u s t t h a t t h e information will be o f va lue to you i n your work and will stimulate fu r the r sugges t ions fo r i t s improvement.

G . C . Warrack, Forester i / c , Research Division.

. .. .

INTRODUCTION

This landform handbook has been prepared primarily for B.C. Forest Service Inventory Division personnel as an a i d t o the i r field undertakings.

The handbook i s not i n i t s f i n a l form since there was an urgency to prepare the book so i t could be used i n the 1974 f i e ld season.

Texts are presently being prepared for the various sections although they may not be ready i n time to be included i n the book. Some tables and figures are enclosed. I t was t h o u g h t tha t , having recently completed the landforms - photo interpretation course, the user would easi ly be able to utilize the information.

Again, due to lack of time, critica-1 editing of the interpretations was n o t possible and some errors are anticipated.

The final version o f the landform handbook i s planned fo r the f a l l . I t i s hoped tha t persons w i n g i t d u r i n g the summer 1974 season will significantly contribute t o the final format. I t would be most appreciated if the .following information could be provided a t the end o f the f ield season:

1. Any errors i n the figures and tables.

2. Inconsistancies or errors i n interpretation. Where the user i s n o t sa t i s f ied w i t h the interpretation, this f a c t should be noted .

3. The general location when i t i s not given, so tha t i t may be added do airphoto descriptions.

4. Any suggestions as to how the handbook may be improved.

5. Photo numbers or examples t h a t the user may come across this sumrrcer, or may already know from prev.ious years which can be incorporated into the handbook. (See the out1 i ne).

Note: Corrections and comments should be made i n the user 's copy. A t the end o f the book a blank sheet i s provided for suggestions.

I t i s sincerely hoped t h a t the handbook - even i n i t s present form - will be o f some assistance to the Inventory Division personnel i n the i r work.

4.'.

Nuretti n Keser , May 3 , 1974

'4

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PART I

PART I1

TABLE OF CONTENTS

A. AERIAL PHOTO

B . LANDFORMS - . I

I1

I11

IV

4. D.

E.

F.

G .

H.

I .

INTERPRETATION Kinds and scale of photographs Elements of airphoto interpretation

Basic concepts

Bedrock types and landforms

Glaciated landforms Erosional Depositional

Non-glacial landforms Fluvial Col1 uvial Aeol i an Lacustrine Mar i ne Organic

Mass Movements

PRACT.f.CRLS ,,AND dEXERC-ISES

GLOSSARY

REFERENCES .

INTERPRETATION OF LANDFORMS FOR FOREST LAND MANAGEMENT IN BRITISH COLUMBIA

Forestry Engineering Watershed management Water qual i ty Ground water Recreation Wildlife Fisheries Mining Pollution Industrial Development Integrated resource management Impact Studies

PRACTICALS AND EXERCISES GLOSSARY REFERENCES

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DENORITIC

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PINNATE

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ANNULAR

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SWALLOW HOLE

DERANGED

RADIAL

RECTANGULAR

BRAIDED

BARBED

FIGURE 2, BASIC DRAINAGE PATTERNS (Pa.rvis, 7950)

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-.. . -. .

/- TABLE 2. GULLY ANALYSIS - SAND AND GRAVEL GULLIES ...

p.tcr' (Keser, 7974)

D e s c r i p t i o n

not a lways present shor t , ,

steep V-shaped "gash" or "nick"

LENGTH

WIDTH .

DEPTH

CROSS SECT I ON

PLAN

. .~

PROF I LE

M a t e r i a l

Sand, gravgl. a p p r e c i a b l e g r a i n s i z e non-cohesive h igh poros i t y

Common Landforms

ou twash p la in V a l l e y t r a i n f l u v i a l t e r r a c e f l u v i a l f a n s -

r a r e l y on eskers o r dunes

GULLY CHARACTER I ST I cs

s h o r t

narrow

shal l o w t o mdderate

1 V-shaped 'I sharp angles a t head f -c ends. a n g l e o f r e p o s e o f t h e mater ia l de termines t h e shape repose " 'Sharp angl e

L

A n g l e o f -

s h o r t s i m p l e a n d d i r e c t seldom has more than one t r i b u t a r y

Foot

Steep, short u n i f o r m g r a d i e n t s h a r p n i c k p o i n t a t head end .

. Foot ' A Head

References

TABLE 3. GULLY ANALYSIS - CLAY GULLIES (Keser, 1974)

D e s c r i p t i o n

"swa 1 e- 1 i ke"

Mar ine , g lac iomar ine c l a y Smooth ly curv ing

Common Landforms Mater ia l

. l a c u s t r i n e , g l a c i o - s m a l l g r a i n s i z e sha l l ow I I n o l I f r i c t i o n a l r e s i s t a n c e lacustrine clay loam t i l l

"L.vL, 1 ow po ros i t y plains shale bedrock.

\

I GULLY CHARACTERISTICS

LAN

smooth ly curv ing , or a t l e a s t n o n - i n t r i c a t e , w i t h a moderate number o f I s im i 1 a r branches. d e n d r i t i c d r a i n a g e w i t h mode r a t e dens i t y .

. .

g e n t l e , f a i r l y u n i f o r m ROF I L E g r a d i e n t mergi.nij impercep,

t i b l y i n t o t h e t e r r a i n a t the head end.

t " '

I

1 Foo t 4 Head

Ref e rences

w TABLE 4. GULLY ANALYSIS - S I L T G U L L I E S (Keser, 1974)

D e s c r i o t i o n

U-shape g u l l i e s " t rough- 1 i ke"

LENGTH

W 1 DTH

DEPTH

CROSS SECTION

P LAN

PROF I LE

M a t e r i a 1

s i l t , f i n e sand weakly cemented s i l t y t o sandy m a t e r i a l . ' .

~~ ~

Common Landforms

.1 oes s mar ine , g lac iomar ine l a c u s t r i n e , g l a c i o - I

lacustrine.

GULLY CHARACTERISTICS

1 ong

moderate

v a r i a b l e b u t t e n d i n g t o b e m o d e r a t e

- v a r i a b l y U shaped, t h e v a r i a t i o n occu r r i ng t oward t he b o t tom Sharp angles-at head end

I s i des

s imi l a r n a t u r e

d e n d r i t i c p a t t e r n ; w i t n 1 1 i gh dens i ty..

i n t r i c a t e , w i t h moderate t o many branches o f 9ead

Foot

g e n t l e , u n i f o r m g r a d i e n t w i th abrup t head end p i n n a c l e s and b u t t r e s s e s

-

Head

F o o t

I cferences

TABLE 5. GULLY ANALYSIS - GRADED (TILL) GULLIES *vJ (Keser, 1974)

O E S C R I PT I ON

V-shaped gullies but curved on p lan view ''grade gull i es "

LENGTH

W i DTH . DEPTH

CROSS SECT I ON

PLAN

PROF I L E

r

~ MATERIAL COMMON LANDFORMS 11

GULLY CHARACTERISTICS

moderate

wide on clay, narrower on sandy tiJ11

shallow on clay but deep in sandy tills

I Sharp anales similar to -granular gullies V-shaped with sharp angles at head ends V

curving w i t h moderate number o f tributaries (less than that of clay) dendritic drainage on old tills

t Foot

steep and short uniform gradient sharp nickpoint at head end A Head

Foot

References

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BEDROCK . GEOLOGY

PZate 2 C d

Sca1e:l inch = 7/2 mile

Photo No. Map r e f :

General location: Gari ba7di Park

. Flow marks )), leyees ttt

. Volcanic cones, C (3ab)

. Secondary cone, Ci (3b)

. _- . ,-.

w.

Secondary features: A fake resulted as a lava blockage; note the absence o f beaches.. Igneous intrusive rqck,G~@.(7,2, a,b). Snow sheets and talus. Radial drainage on cones. I >

a b C d

CENTER Photo NO* BC 7521 : 135436 Wap ref :

General loca t ion : Garibaldi Park - Rubble Cr. Primary features : BEDROCK

. ?rWlacial lava flow ie (entire photo)

. Flow mark ) ) ) (labcd, 2abcd)

. Levkes H-F (lab, 3abc) I

Scale: 1 inch = 1/4 mile

Secondary features: Sl ide, L (3 ,4 , bl,c). Less active pa r t of the slide has some vegetation (Zc, 3c). Note the stream (Rubble Cr.) coming through the debris ,

/ (4c). Lake, (3,a) is drained by them. (What is the cause of the sl ide?).

BOTTOM

Photo No* BC 51 12: 60-61 Map ref : General location: Terrace - Aiyansh - Nass R. Primary f ea tu res : BEDROCK

. P o s t gfac ia I . l ava . f i e ld , (bed ) , i b (123.,

. Coll apsed chambers e (1 bcd, 3 b )

bcd

Secondary features : F1uv-j a1 fan , Ff (2a , 3a) ; Aiyansh Indian V i 7 lage ( Id) ; Flood plain,

CO

f P

Scale:l inch = 1/2 mile Cc (4ab) ;

Plate 2

C d Ti) P -

Photo No. BC 2268: 26-27 Map ref: General location: Sayward forest - Campbell R . Primary features : BEDROCK

>&

. Volcanic (beds), ie (lab, Zabc, 3abc, 4abcd)


Secondary features: Glacial t i l l - shallow over the bedrock, Tb ( en t i r e photo) ; Sandy deposits, F (Kc, 2c); (note gully characterist ics); Young plantation, (1, 2 , cd); Old granite D. Fir stands, (3b, 4ab).

B b C d

CENTER Photo No. BC 4320: 68-69 Map ref : General location: Quadra Island - Open Bay Primary features: BEDROCK

. Limestone, sl (labc, 2abc, 3abc)

. Sinkholes ( l b , 2bs)

*/’ -


Secondary features : Beaches, Mb (3bc) ; Del t a developments Mt (3b) ; Old logging landing ( l a ) .

e d

UOTTOlll

Photo No. BC 1214: 84-85 Map re f : General location: Alice Arm Primary features : BEDROCK

. Volcanic outliers, ie ( I b , .2abc, 3abc, 4cd)

. Sedimentary rcck (Bowser sediments) -- ” ( res t of photo)

Scale: 1 inch = l / 2 m-i’le Secondary features: (Cour-besy of dr. K. f?ortL-ote)

Photo No. E& 443: 46-47 Map r e f : General locat ion: Terrace - Aiyansh Primary features: BEDROCK

. vol canic cone, c ( 3 4

. Cjnder cone \ e (3a)

Secondary features: Unstable slope, Q (Zab, 3ab, 4b); Colluvium, Cc (4ab); Lake developed by lava blockage, La< (46).

CENTER.

Secondary fea tures :

. Incorrect i l lust rat ion.

. VoJc.anic rock, ie. (3b, 4b)

Map ref:

Scale: l inch = 7/2 mile

Q b e d

1

2

3

b c d

I

2

3

Secondary features: Fluvial fans Ff (labc, Zabcd, 3abcd) ; Scale: 1 inch = 1/4 mile

Flood plain Fp (.3,4, abcd) ; Terracettes , t - - (1,2, bc) .

PZate 4

Photo No. BC 5178: 587-188 Map ref': General iocation: C l i n t o n - The Chasm Primary f ea tu res : BEDROCK

. Volcanic (lava beds) i s (entire photo)

C d

Secondary features: Me1 Water channel $$ (Zcd, 3bcd) Co l luv ium, Ct ( a t the bottom o f chasm); Railroad settlement . . (3a).

. Volcanic - post-glacial lava flow, ie;$s (labc, Zbc, 3abc, 4ab)

; Rotational slide Q.h (3d); *.tr (2,334, abcd); Hwnan

a e d

Scale : 1 inch = 1/2 mile

Secondary f ea tu res : Ti7 1 , Tb -- ( lab, 2ab , 3a, 4cd) ; Fluvial terrace, F t (3d , 4 d ) ; Flood plain, Fp (2d, 3d); Logging road +t; Parkjng area made by cats :: ( 3 ~ ) .

"

BOTTOM

Photo SO. BC 866: 33-34 Map r e f : General location: Garibaldi Park - Mamquam R. Primary f ea tu res : BEDROCK

Proglacial lava f low, fe. 39 ( l c d , Zcd, 3d, 4d)

. Levee H+ {lcd, 2cd, 3cd, 4d)

Scale: ? inch = 1/2 mile Secondary f ea tu res : Old logging OL (Zc , 3c, 4cd); Sub-alpine f o r e s t , SF (Za, 3a, 4a).

PZate 5

. Granitic r,ock ii (Enrire-Photo)

CENTER Photo NO. BC 5737: 187-188 Map ref:

Granl' t i c rock

.

Scafe:l inch .= 1/4 mile (Courtesy of Dr. K. Jorthcote)

Secondary features: T i l 1 shallow i n general, Tb ( en t i r e photo) ; Flood p ' i a in , Fp (4abc) ; Imperfectly drained up1 ands ' W (labcd , 2ab).

c d

BOTTOM

Photo No. BC 5053: 147-148 Map ref : I

General location: P r i m a r y f ea tu re s : BEDROCK 2

. Post-g?acial l a v a f l o w i.e?-(-Pab, .~ Zabc, 3bcd, 4abd) 3

. Vol can-ic cones xx

. Cinder cones - . kt - ,

4

. " Scale: 1 inch = 1/4 mile

Secondary features:

PZate 6

. Granjtje rock (en t i re photo)

Secondary f ea tu res : Fluvia l de l ta , Fd ( I d ) . . I

Map ref:

General location: liorseshoe Bay, near Vancouver Primary features : BE~ROCK

'. Granitic 1 bedrock ( en t i r e photo)

. Note texture pattern

Sca1e:I i n c h = 1/2 mile

Secondary f ea tu res : Marine benches or raised beaches, Mt (2abc, 3a) ; F l u v i a l fan, F f (3a) ; Fluvial de l t a , Fd .(3a) ; Ferry terminal and ferry (2d) . Note the land use on steep mountaa'n terrain.

c d ., ,

BOTTOM Photo ' 0 . BC 2318: 32-33 Map ref:

Genera l loca t ion : Gooseneck lake, Sayward fores t Primary features ; BEDROCK

. Granitic rock (en t i re photo)

'hJ.#' Scale: 3 inch = 1/2 mile

Secondary features : Outwash, Gd (3d, 4d) ; T-il I-kame compf ex, Ta-Gk ( I , 2 , 3 , cd) ; V shape stream channel on bedrock +++.

Photo No. tic 1034. 45-47 Map r e f : General l o c a t i o n : B i g White Mountain, Vernon Primary features: BEDROCK

. Granite rock (entire photo)

Scale:: 1 inch = 1 mile (Courtesy of 2&. 3. KouaZZ)

Secondary features : Cirque basin, I c ++f (Icd , 2cd) ; Tarn, I,it : : (2c) ; Col , I1 x (2d) ; Horri,@In (2d) .

General location: North Nest Territories Primary features: BEDROCK

. Granitic rock, xx ( I , 2 3 4 , abc)

. lineament $++ (fault?) l a , 2a)

Secondary features: Marine deposi.t, M -- (1;2,3, bcd); Active solifluction xx, ”

( lc , 2cd).

BOTTOM

Photo BC 5348: 233-234 Map ref : General locat ion: Salmo Primary features: BEDROCK

, 2- ”

PZa-te 8 C d

' I U ?

Photo No. BC 5136, '191-192 Map r e f : General location: t r i c Lake, Vancouver Is. Prima'ry f ea tu res : BEDROCK

- ,"- '

. Massive and thick bedded limestone, SI

e Thick-bedded tuffaceolts #roc1 a s t i c rocks s

> !

Scale: 1 inch = 1/4 mile (Courtesy of Dr, K. N o r t k o t d

Secondary features:

CENTER

. Sedimentary rock - moderately t o steeply t i p p i n g , s, (entire photo)

. Cirque, PC 899

Secondary features: Coalescing colluvial cone Cc (2b, 3bc, 4bcd) ; Rock s t i l l ' v i s i b l e a t t h e bottom o f the cirque, R - (3b, 4bc).

b c d

BOTTOM Photo N O . BC 4184: 66-67 Map re f : General location: Roc k i es

Primary features : BEDROCK

. Sedimentary rock - f la t - lying to gently d i p p i n g

Scaje: 1 inch = l /4 mile Secondary features : Cirques IC *; Tarn, I t (2d) ;

Rock glacier, I r (2c); TaTus, Ct :: (4ab) .

Secondary features: Glaciofluvial deposi ts (esker) Ge :: ( lab, Zbcd, 3bcd, 4a); $1 u t i ng on the bedrock (3bcd, 4abcd) ; Directton of ice movement 4a ts 4d.

General location: Wood Buffalo Park, Alta. Primary features : BEDROCK

. Limestone terrain - karst topography, S.1 , (enti re photo 1

. S i n k holes ( l a , 3abd, 4bcd)

. Col I apsed trough =;. ( l b s 2ab)

Secondary features : Sand dunes -I-++ ( 2 $3 *4, abcd) .

EOTTOM

'hot' BC 41 08: 174-1 75 /Map r e f : General location:

Primary fea tures : BEDROCK

. Moderately steep lying sedimentary rock, s , (en t i re photo)

b C d

D

2

4

Scale: 1 inch = 1 mile (Courtesy of Dr. D. Lacate)

cl b C d

'"le: 1 inch = 1/4 mile

Plate 20 c d

Phbto K O . BC 7288: 229-230 vifi I ap r e f :

General l oca t ion : “ W

Primary f ea tu res : BEDROCK

. Limestone t e r r a i n . - Karst topograph), s I, (enti re photo)

. Sink hole e ( I d , Zc, 4b)

Scale: 1 finch = 1/2 mile (Courtesy of Dr. K. Northcote)

Secondary features: Extensive erosfsn on limestone, E , xx ( labc, 3b, 4b) ; F l u t i n g , xx

(2ab); Direction,of ice movehent, 2a - 2d).

C

CE~TER Photo No. BC 5374: 78-79 Flap ref: General location: North Pender Is . , Gulf Islands Primary features: BEDROCK ~

. Sandstone - steeply d i p p i n g , s c ( e n t i r e photo) *- s

Scale3 inch = 7/2 r i l e

b c d

BOTTObl

Photo No. BC 5374: Map ref: General location: A c t i v e passP Maine fs.,’Gulf I s lands Primary f ea tu res : BEDROCK

. Steeply bedded sandstone. s c (entire photo)

“b ..&- Sca1e:l inch = 1 Fi l e

Secondary features : 2 Ferries entering t i le Active Pass from opposite directions (2ab).

PZate 22 d 7i.C p -

Photo No. BC 5309, 243-242 Nap ref : ’

General loca t ion : Corein area, Rockies Primary fea tures : BEDBOCK -4

b, i

. Moderately d i p p i n g sedimentary rock - sandstone/ shale sequenc& (entit-e photb)

. Para1 1 el ridges o f , resi stance beds (sandstone)

. Tonal differences between beds ..

Scale:l i n c h = 1/2 mile

(Courtsoy of Dr. x. r jor thwtd

Secondary features : Cirques +b+ (234, abcd) ; Tarn i r . (3b) ; ’ A7 i g n e d trees a7 sng beds, (3,4$ bcd) .

CENTER Photo No. Map ref:

General location: Primary fea tures : BEDROCK

. Steeply ti I t & metam kic rocks tt (1,2,3,4, abcd)

Secondary features : Deeply cut l a t e ra l moraines, ## ( 2 , cd) ; Lateral moraine TI (3,4, cd); Outwash, 0 (3.,4, cd); Fluvial fan, Ff’(3d); All.uvia7, A, ( M ) .

a b C d

BOTTOM Photo NO. BC 5374: 78-79 Map r e f : 1

General location: Worth Pender Is., Gulf Islands Primary fea tures : BEDBOCK 2

. See p la te 1 0 3 centre, for comments.

4

49 Scale:l inch = 7 mile

Secondary features:

'TOP

Photo N O . BC 7117: 58-59 Map ref,: General locatiori: Kocltenay Lake Primary features: BEDROCK

. Metamorphic rock - fo l ia ted , m t f ( en t i re photo)

. Fol i ation exaggerated by the, ice moving in the same direction. as the fol ia t ion.

. Ice movement from l a to 4c.

Secondary features:

CENTER Photo No- A 15159 41-42 Map ref: General locat ion: Mood Buffalo Park, Alta. Primary features : BEDROCK

(enti r e photo) . E i mestone temain - karst topography, $1

. S i n k holes 0 . (3a, 4abd)

. Dry stream channels - col lapsed channel /// - underground streams (4bc, Zbc, 3ac, 4c).

Secondary features :

BOTTOM

Photo No- BC 1251 : 102-103 Map r e f : General location: Round Mtn. , Telegraph Cr. Primary features: BEDROCK

3abc, 4abcd) . Sandstone - gently d i p p i n g sc1 -- ( l a , Zab,

"

$8 ndstone - steeply dipp ing and folded, Sc2, (Ibcd, 2bcd, 3cd)

U b e d


PZate 22 Q C d 'TO 2 -

Photo NO. BC 7127: 58-59 Map ref.: iI

General locatioa: KoOtenay Lake Primary f ea tu res : BEDROCK 2

. Metamorphic rock - fo l i a t ed , m,f (en t i re photo)

. Fo7 i a t i o n exaggerated by the, i c e moving i n 3 the same di rectjon. as the fo7 i ation.

. Ice movement from l a to 4c. 4

Scale: I inch = 1/4 mile

Secondary features :

C d

CENTER Photo No- A 151 59 : 41-42 Map ref: General location: Mood Buffalo Bark, Alta. Primary features : BEDROCK

(ent i re photo) . Limestone terrain - karst topography, Sl

. Sink holes 8 . (3ag 4abd)

. Dry stream channels - collapsed channel /// - underground streams (4bc, 2bc, 3ac , 4c),

Secondary f ea tu res :

U b e d BOTTOM

Photo No- BC 1251 : 102-103 Map ref : General location: Round Mtn., Telegraph Cr. Primary features : BEDROCK

3abc, 4abcd) . Sandstone - gent ly d ipp ing , S C ~ -- ( l a , 2ab,

ndstone - steeply d ipping and folded S C ~ ,

"

( Ibcd, ilbcd, 3cd9

Scale: 1 inch = 1/2 mile Secondary f ea tu res : Cirque, $.,+I+ (3cd., 4abcd) Col luvium;c&-

(4abcd); Rock g1a,cier,i',,,(4c).

PZate 34 b c d

Photo '0. 6C 5069: 107-108 Map ref: General location: Salmon R . , near Salmon & Fraser junct. Primary features : FLUVIAL

. Flood p l a i n Fp, ( l a s Zabcd, 3cd)

. Oxbow lakes, Fo /// (Zbc, 2d)

. F1 u v i a1 -terrace underlai n by 1 acustri ne Ft/Lg (labc, 2bcd)

. Fluvial terrace, F t (3bcd)

. Old meander scars (Courke& of Mr. G. Runku)

Secondary features: . tacustri ne deposit, Lg @ (1 cd Zacd, 3ab, 4abcd) ; Eroded lacustrine Lg (Eg) : (3cd , Mic) -

". ! i '2

CENTER Photo 30. BC 1134: 98-99 Map ref: General location: Bonaparte R. - Caribou Hwy. Primary features : FLWJAL

" . Fan. Ff -- (labch, Zabcd)

. Flood p la in , Fp (Zabcd, 3abcd, 4abcd)

. Old meander (2ac, 3d, 4cd)


BOTTOM


Photo NO. BC 7231: 26-21 Map ref : General location: Golden area (Blaeberry R . ) Primary features : FLUVIAL

, Flood plain - braided stream, Fp ( labs, 2abcd , 3d)

. Flyvia l ' terrace, F t (1 bcd, 2b, 3c)

. Recent fluvial deposits, Fr : (2abd) 4

Scale: 1 inch = 1 / 4 mi le

Photo NO. 6C 37 1 : 56-57 Mag r e f : General l oca t ion : Vanderhoof P r i m r y f ea tu res : FLUVIAL

. Flood p la in , Fp ( labcd, Zabcd, 3abcd)

. Fluvial - recent, Fr @- ( lcd , 2cd)

b C d

General location: 6owron R.

Primary features : FLUVIAL . Flood p la in - Fp :: (vertical accre t ions)

(lad, 2ad, 3a, 4abd)

i Flood p l a in - Fm ( l a t e r a l accreti’ons bar meander type) 1 bc, ‘Zbc, 3bcd 4b)

. Ox-bow lake, Fiv (3cd, 4cd)

. Plug ( i n oxbow lake) /// ( 3 d , 4d)

. PJote meander migration Secondary f e a t u r e s : Log jay ‘1 (43) .

BOTTOM

Photo No. BC 1134: 87-88 Map re f : General P O C ~ ~ ~ O R : Bonaparte 1. *- Caribou HWY.

Primary features : FLWIAL . Fan, F f (labcd, 2abcd, 3abcd , 4ab)

. F1 ood plai n ,FX: : (complex)-- (;2d, 3cd, 4ab) I I

. Old meander deposits /// (3d, 4cd)

PZate 36

TO P - Photo NO. BC 113% 102-902 Map r e f : General loca t ion : Bonaparte 1. area Primary f ea tu res : FLUVIAL

. F l u v i a l fan, pf -'- ( lcd, 2cd, 3bcd)

. Flood plain, Fp (primarily vertical accretion)

-.-

(3abd , 4abcd)

. Drainage channels on fan __

. Old channel scars

0 b C d

C

Secondary f ea tu res : T i 1 1 , Tb : : ( 1 abCd 9 2abc).

b C d

CENTER

Photo NO- 8C 5063, 42-43 Map ref: General loca t ion : Fraser River, near Richmond Primary features : FLUVIAL

. .Flood plain, Fp (vertical accretions) (labcd, 2abcd, 3ab)

. Flood pla in , Fm (bar meander type} (3bcd, 4th)

. Levee, F l /// ( k d 9 3ab, 4a)

. Old sand bar, Fs : (3cd, 4bc)

. Old channel scars Secondary features: organic, 0 (labcd)

Scale: 1 inch = 7/4 mile (Courtesy of Mr. G. Rur,kal

BOTTOlLl

Photo NO, BC 1683: 17-18 Map ref : General location: Fraser River, near Chilliwack Primary features: FLUVIAL

. Flood plain, Fm (bar meander type - this is an i n the Fraser) : (1 23, abcd, 4cd)

. Abandoned channels Fo /// (1 234, abcd)

. Flood plain, Fb (vertical accretions)(lcd)

Se'corl Jan$ ir) f a t b r e ~ : b-?r F.b_ " (4a) Clearing by man xxx (2bc, "

i s l a

Scale: 1 inch = 1/4 mile 3cd).

Plate 37

"

Photo N O . 5C 5275: 303-]04 Map ref: General location: Okanagan E. near Ke'lowna Primary features : FLYVIAL

. Fan d e l t a , Fd (1 bc)

Secondary features: T i 7 1, Td (2abc 3abcd 4abcd) ; Kame terrace, G k -- " ( l a b , 2ab); Kame terrace rhnants. /// (3abcd); Outwash delta (kettled) (lcd, 2cd) ; Kettle

CENTER "

Pl10~0 Nod BC 5065: 7 76-177 Map ref: General loca t ion : Fraser Val1 ey, near White Rock Primary features : FLUVXALj 2

I

. Flood plain, Fp (vertical accretion) (enti re photo) 3

. Old channel scars 4

Secondary features:

d

I

BOTTOM "

Photo No. BC 5097: 75-76 Map ref: General. location: Oyster River delta, Vancouver Is. Primary features: FLUVIAL

. Del ta , Fd (labc, Zabcd)

Fluvial terraces :: (various levels) (3b, 4ab)

Scale: 1 inch = 1 / 2 mi le Secondary f ea tu res : Outwash terrace, G t (marine washed a t h i n veneer Of

marine/ outwash) $t (Zc, 3ac, 4b).

Plate 38

Photo NO. BC 613: 35-36 Nap r e f : General location: Meri tt Primary features : FLUVIAL

. Flodd plain, Fp -- ( lab , 2ab, 3 b , 4b)

. Fan, Ff . (lcd, 2cd)

-L

I

Secondary features: T i l 9 Td ( I d , 2d, 3cd, 4d) ; Lacustrine, Lg (Za, 3abc, 4abc) .

CENTER Photo 140. BC 1734: 104-105 Map ref: General location: Bonaparte R. Cariboo Hwy. Primary features: FLUVIAL I

i . Fluvial fan Ff #: (2abcd, 3$bcd, 4bcd)

. Flood plain, Fp z: (3a, 4ab)

Secondary features : Ti 11 , T g l ahd , 4ad) ; Ta

BOTTOPI

Photo No- BC 2620: 82-83 Map r e f : General loca t ion : Kamloops area Primary f ea tu res : FLUVIAL I

. Flood plain, Fp -- (verticdl, accretions) (

. Flood plain Fm ) ) ) ) (laterai accretions)

. Fluvial terrace, Ft ( l a , 2a, 3a, 4a)

. Old meander sc ro l l s G?

“

3bcd, 4cd)

lus, Ct ( l c

lcd, Zbcd,

F l u v i a l fans , Ff : : (3d , 44) Scale: 1 inch = l / 4 mile S6condary features: Til 1, Tb -k (lad, Zad, 3ad, 4ad)/

~

- 1

j

PZate 39

-TQp ; __ P ~ O ~ O SO. A 15297: 44-45 Map re€: I

General location: Peace River Valley Primary features : FLUVIAL 2

. Flood plain, Fx (complex type - lateral accretion i s dominant) (Iabc, Zabc, 3a, 4a) 3

. Meander scar X2 (1 abc, 2abc, 3a, 4a)

. Fluvial terrace, F t : : (sa, 4a) 4

. C u t banks "+ ( lcd, 2bc, 3a, 4a)

...

Scale: 1 "inch = 1 m i l e (Courtesy of Dr. D. Laeate)

Secondary features : Lacustrine sands L -- (lcd, 2cd ' 3bcd, 4abcd). "

General location: Primary features : FLUVIAL

. F1 ood plain 1) Fp : : (verti caFaccretions on o ld clay bed) (lcd, 2bcd, 3bcd, 4cd)

. Flood plain Fp :: (lateral accretions) ( l a , 2a)

. Lateral planations by the rfver on old jake bed Note the terrace remnants and slump features, Fp zT (2cd, 3bcd, 4cd)

Sca1e:l inch = 1/4 mile

. An island made primarily by l a t e ra l acc re t ions $3 (4ab.) Secondary features : Slump scarps w on lacustrine bed Lg (2cd; 3d, 4d).

BOTTOM

Photo Noi BC 7211: 31-32 Map r e f : General location: Golden(B1aeberiry R.) area Primary features : FLUVIAL

. F1 ood plain = presently active (braided stream)

. Flood " plain, older i n age, 'Fp $2 (3abcd);

. Bar deposit : : ( l c )

Fp , ( lcd, Zabcd)

Fp2 -- (3abcd, 4ab)

Secondary f ea tu res : T i 11, Tb (labcd, 3cd, 4abcd).

'

I 1


PZate 40

'i'L1 i' ".

Photo No. 6C 5065: 40-41 Map r e f : General location: Lower Fraser Valley Primary features : PLUVIAL

. Flood p l a i n - lateral accretions, Fp (entire photo)

. Old channels ///

R C d

3-

Scale: 1 inch = 1/4 mile (Courtesy of Mr. G. Runka)


a b C d 1 1

CENTER Photo A 14970: '109-110 Map ref : General location: Golden area. Primary features : FLUVIAL

. Flood plains - braided stream, Fp -- " ( Id , 2cd, 3bc, 4a)

* Fluv ia l fan deltas, Fd :: (2c, 3bc)

. Fluvial fans FF, @ (lcd) Scale: 1 inch = 1 mile

. . .

Secondary features : Colluvial /// ( lc 2bc) ; Bedrock - ti 11 complex, B-Tb (la,bc, Zabc); Ti l l - bedrock - ti 11 complex (2d, 3cd, 4abcd); Outwash terraces , G t (Za, 3cd, 4bc)

BOTTOM

Photo No. A 15173: 23 General location: Peace River Primary f ea tu res : FLUVIAL

. Flood plain mixed type, Fx, accretions are dominant

. Oxbow lakes, FW ( I d , 2d)


Map r e f :

however, 1 ateral

Photo NO. EX 5070: 1 O5-107 Nap ref: General loca t ion : Prince George area Primary features : FLUVIAL

. Flood plain - braided, Fb: (lcd, 2bcd3,3ab, 4a)

. bote

Secondary 3bc, 3 4 ;

CENTER Photo No.

many meander cut-offs and oxbow lakes

fea tures : Glaciofltivial delta, Gt' (3ab, 4a); Til l-ablation, Ta (Zcd, 4b); Til l-ablation w i t h some outwash del ta remnants, Ta(G) (labcd, Zab, Lacustrine deposit, Lg (2d, 3cd, 4bcd).

BC 1784: 44-45 Map ref: General location: Fraser R. - lower Fraser Valley Primary features : F L U V I B

. Flood plain - mixed type, ( l a t e ra l and ver t ical accretions) FX, (enti re photo)

\

. 07d channels /// ( l a , 2b, 3abd, 4bc) Levee fl BP (Za, 3a, 4ab)

Secondary features : Drainage d i tch ++++ .

BOTTOM Photo N O . A 13247: 29-30 Map ref : General location: Fraser River Primary features: FLUVIAL

" . Flood plain, Fp -? (mainly la teral accret ions)

. Fan, F f :: ( I d ) . Meander cu t -o f f (oxbow lake) $! ( l a b , 2ab)

. Is lan 2 /// ( lab, 2abd, 3d) . P l u g It x (Zab, 3ab) . F7uv ia l de l t a , Fd ( lab)

( 1 bed, Zbcd, 3abc, 4a)

"

Secondary features : T i l 7 , Tb/B ( l abcd , 3cd, 4bcd) ; Outwash terrace (or kame) G t (2a) .

Plate 42

TOP - Photo No.

'L General location: Primary fea tures f


CENTER

Photo No.

General location:

Primary features :

ICs


BOTTOM Photo No.

General location:

Primary features:

Secondary features:

Map r e f :

Scale :

~ Map ref:

Scale :

0.

Map r e f :

Scale :

TOP - P'noto No.

e, General location:

Primary features:

Secondary features:

CENTER

Photo No. General location:

Primary features :

L


BOTTOM Photo No, General location:

Primary features:

Secondary features:

Ma$ ref:

2

3

4

Scale :

Map r e f :

Scale :

r.

Map r e f :

Scale :

PZa-te 46

Photo Yo. 6C 623: General locat ion: Primary f ea tu res :

53- 54 Map ref: Fraser River AEOLIAN

. Sand dunes on old outwash terraces As, A I (,2bc, 3bcd, 4b)

Plate 47

Secondary features- Outwash . terrace, G t (labc, Zbc, 3bcd, 4d) ; Kame terrace - remnants, Gk $+ (2a, 3a, 4a); Alluvial terrace, Ft 2; ( lab , 3bc). +”

General location: Wood Buffalo Park, Alta. Primary features : AEOLIAN

. Sand dunes 3 primarily U-shaped As ( l a b , Zab, 3abcd, 4abcd)

. Di rec t ion o f wind from l a to 4d

Secondary features : Kettl es , : : (lcd , 2d) .

BOTTOM

Photo NO. A 15166: 102-103 Map ref: General location: Wood Buffalo Park, A1 t a . Primary features : AEOLIAN

. Sand dunes 3 longitudinal - some barchanes (labc, 2cd, 3ad, 4bd)

Scale: 7 inch = 1/2 mi le (Courtesy of Dr. D. Lacate) Secordary features : S i n k holes o (2c, 3abc).

PZate 48

4 I

CENTER Photo No.

General location: Primary fea tures :

Secondary features:

Map ref:

Scale:

BOTTOM

Photo No.

General location:

Primary f ea tu res :

Map ref:

Scale : Secondary features :

GLOSSARY

ABLATION MORAINE: Where the rate of glacier ablation i s relat ively h i g h , englacial dkbr i s i s exposed a t the ice surface. The resulting cover o f , bou,lders and rock debris i s called ablat'l" on t i l l and the feature i s cal'led ab1 ation morai ne. In the process the presence of dark- coloured material on the ice surface reduces the albedo and greatly raises, the rate o f heat absorption. The ice becomes stagnant and the accumulation of ablation moraine on i t s surface becomes increas- ingly rapid, and ablation t i l l i s lowered i n situ from the melting ice surface onto the top of lodgement till. (Ref. .#2)

ABLATION TILL: I Nonstratified and nonsorted t o f a in t ly s t r a t i f i ed and poorly sorted glacial drift deposited from a superglacial posi.tion through

*w melting of underlying stagnant glacier jce. Most abla t ion t i l l i s 'L. loose and characterized by partial loss of fine constituents (si1 t ,

clay) and by random orientation o f i t s c las t s whereas lodgement t i l l i s generally more compact, having retained most o f i t s f ine consti t- uents. Both the fine materials and boulders may preserve a preferred orientation, indicative of former ice movement. The term includes both melt-out t i l l and flow t i l l , as suggested by the classification be4 ow: TYPE ORIGIN CLASSTFICATION FLOW TILL (FLOWTILL) Supraglacial, also Ablation T i 11

EX I ST1 NG

Superglacial

Superglacial MELT-OUT TILL Supragl aci a1 , a1 so Ab1 a t i on T i 1 1

LODGEMENT ' (BASAL) Subgl aci a9 Lodgement T i 11 TILL (Ref. #2)

" AEOLIAN (EoTian) : Applied to deposits arranged by the wind, as the sands and other

loose materials along shores, etc. (From Eolus, the god of winds). Sub- ae r ia l i s o f ten used i n much the same sense. 2. Applied to the erosive action of the wind , and t o deposits which are due to the transporting action of the wind . (Ref. # l ) '

AGGRADATION: The deposition or building-up of sediments by stream, wave or wind action. An aggrading r ive r i s one which .actively elevates i t s bed,by deposition of sediments. (Ref. #2)

ALLUVIAL (See A1 1 u v i u m )

ALLUVIAL FAN: A fan-shaped deposit with i t s apex pointing upstream and formed by a stream a t a p o i n t where i t abruptly leaves a narrow valley or ravine and enters a larger valley or an open plain. Fans form where a constricted Val 1 ey ceases abruptly , n o t solely where there i s a change in gradient of the streambed. T h u s fans form where streams issue from mountains and steep-gradient tributaries. Alluvial fans a r e f l a t t e r t h a n alluvial cones and d i f f e r from deltas by being deposited mainly i n a land environment rather than i n a body of s t a n d i n g water. Alluvial fans reveal great diversity of size, slope, grain-size distribution of sediments and i n characterist ics of their source terrane. A great deal of useful information a b o u t alluvial fans can be derived from an airphoto study of their source and deposition areas, slopes, environments and histories of sediment deposition. Among the complexly i nteracti.ng factors to be assessed are the kinds o f so i l s and rocks i n the source areas (watersheds) ; topography, vegetative cover and hydrology of the drainage basin contributing sediment; slope of the stream channel ; stream-discharge pattern; climatic and tectonic environment; c lear! water vs viscous mudflow deposition; and geometry of the fans:. Alluvial fans are charac- t e r i s t i c of tectonically active regions. Many factors affect the slopes of fans. Fans produced by lower discharge$ have steeper slopes. Fans composed largely o f mudflows or h i g h l y permeable openwork (sieve) deposits are steeper than fans composed of finer f luvial deposits. Generally the coarser grained t h $ f an deposit , the steepqr i t s slope. Fans formed from large volumes of sedtment per unit 'drainage-basin area tend to be steeper t h a n fans formed from small volumes per u n i t drainage basin area. Clayey source rocks (shales , s i l ts tones, mudstones) form larger fans having f la t te r s lopes than coarse source rocks (sandstones and conglomerates). Most alluvial fans i n Canada, however, are derived from eroded glacial and glaciofluvial deposits rather than bedrock. (Ref. # 2 )

ALLUVIAL FILL: A body of alluvium occupying a stream valley bottom and conspic- uously thicker than the depth of stream channel i n i t . (Ref. #2)

ALLUVIAL FLOODPLAIN SEDIMENTS: Among the chief morphological elements t h a t may make u p floodplain sediments are p o i n t bars, channel bars and a l l u v i a l islands, cut-off channels (oxbows) and channel f i l l s , crevasse splays , natural levees, and flood basins or backswamps. In the i r manner of construction and i n the natpre of their constituent deposits, these elements form two fundamentally d i s t inc t groups. P o i n t bars, channel bars and alluvial islands result from lateral accretion of streambed

3

W load dur% ng the sideways migration of channels, and these sediments are common t o a71 floodplains. After overbank f low, vertical accretion o f suspended load leads t@ the construction of a topstratum of natural levees, crevasse splays and flood. basins and backswamps on top of the substratum of genkrally coau'ser lateral-accretion deposits. Channel f i l l s a r e not easfly placed : i n either category because they consist p a r t l y , and sometimes wholly, of bed-load material. Grain-size avail- a b i l i t y and volume of load, stream gradien t , mean annual discharge, mean annual fiood discharge,and bankful discharge, and braided vs meandering habit are useful guides t o estimating the l i keiy type and stratigraphy of sediments below alluvial floodplains. (Ref. #2)

ALLUVIAL RIVER:; A'rivGr tha t has formed i t s channel out o f i t s own transported sed-iment. The sediment i t car r ies , ,except for the wash load, l's s-imi 7ir t o t h a t i n the r iver bed. (Ref. #2)

ALLUVIAL TERRACE: Terraces composed of Val ley- f i l l sediments that were originally deposited by stream actSon i n former geologic time and la te r cu t through by the stream, 1 eaving the former floodplain surface some distance -above the bed o f the present stream. , (Ref. #2)

ALLUVIUM: (1 ) : A general term fo.r all .detri tal . deposits result ing from the operations d f modern r ivers , thus including the sediments laid down i n r iver beds, flood plains, lakes, fans a t the f o o t of mountain slopes, and estuaries. (2) : The rather consistent usage of the term throughout i t s .h i s . to ry makes i t quite clear t h a t a l luv ium i s intended to apply to

o f seas and lakes are not intended to be included, and t ha t permanent submergence i s n o t a cr i ter ion. Alluvium may become l i t h i f i e d , as has happened frequently i n the pas t , and then may be termed ancient alluvium.

k w + stream deposits of comparatively recent time, that the subaqueous deposits

> '

(Ref. # l )

All so known as a comb ridge. (Ref. #5) A<hE: A jagged, narrow mountain-ridge crest result ing from glacial erosion.

AVALANCHE: A mass o f sriow which becomes detached and s l ides down a mountain side. Sometimes foosely used i n relation t o masses o f rock and soi l which should more properly be called landslides. (Ref. #3)

BANK: (1 1 The rising ground bordering a lake, river, or sea; on a r iver , designated as r i g h t or l e f t as i t would appear facing downstream. ( 2 ) An elevation of the sea f loor of large area , surrounded by deeper water , b u t safe for surface navigation; a submerged plateau or she l f , a shoal , or shallow. (Ref. #1)

BANK, EROSION: The wearing! away of a bank of a stream by flowing water. (Ref. #2)

w

BAR : An elongate ridge commonly composed o f sand or gravel sediment and b u i l t offshore by waves and currents. I ts c r e s t i s usually submerged b u t may be exposed d u r i n g low tide. T'n r ivers an ovoid streamlined deposit of sand and gravel having a steep drop-off side downstream, which i s bu i 1 t by currents, and may be exposed during low r iver stages. (Ref. # Z )

4

BARCHAN: (1 1 A dune h a v i n g crescentl’c ground plan, w i t h the convex side facing u the wind; the .prof i le i s asymmetric, w i t h the gentler slope on the convex s ide, and the ’ steeper slope on the concave or leeward side. ( 2 ) The crescent or barchan type i s most character is t ic of the inland desert regions. I t presents a gently convex surface to the wind , while the lee side is steep and abrupt. The horns of the crescent mark the lateral advance of the sand. I t s wide distribution and a l l b u t universal presence i n the sandy deserts of a l l con then t s make th i s type the normal one fo r sand h i 1 1 s formed on, an open area. (Ref. #1)

BASAL CONGLOMERATE: A coarse, usually well-sorted and lighologically homogeneous sedimentaty deposit which i s found just abovC an erosional break. The i n i t i a l stratigraphic u n i t overlyihg an unconformity, formed by a rising sea 1 eve1 or an encroaching sea.

BASIC ROCK: Ingenous rock that contains a relatively low percentage (below 50 to 55 per cent) of s i l i c a and a h i g h percentage of metal 1 i c bases ( i ron, calcium, magnesium, etc. 1 (Ref. #5)

BEACH: A body o f wave-washed sediment extending along a coast between the landward limit of wave action and the outermost breakers. On ocean beaches the upper beach r i ses to a height corresponding to the maximum storm swash 1 imi t of recent history (berm c res t ) and includes the beach face, various berms, and the backshore. The beach face i s usually separated by an abrupt break i n slope from the lower foreshore step or low-tide terrace ( i n the order of 1 : 100) to the beach face ( i n the order of 1 :IO). The upper beach i s generally marked by one or more berms separated by abrupt beach scarps, which represe%nt the limits o f recent storms and resulting wave building. Fairly constant relationships of slope t o median grain size of sandy ocean beaches exist: a fine sand o f 0.57 mm median diameter m i g h t correspond to a beach’having a 1 :40 slope, for example whereas a coarse sand o f 0.65 mm mean size often corresponds to a 1 :8 beach slope. Eroding beaches f l a t t en whereas accumulating .beaches steepen. Thus protected beaches a re steeper for any given sand s ize khan exposed beaches. (Ref. #2)

BEACH LINES: See Beach Ridges.

BEACH MIGRATION: Movement of beach out from original location such as through longshore current action.

BEACH RIDGES: An essentially continuous, mound of beach material that has been heaped u p by wave or other action. Ridges may occur singly or as a set-tes of approximately parallel deposits behind the beach. Each ridge marks the position o f a preexisting strandline and is a feature of prograding. (constructional) shores. Beach ridges are b u i l t where the beach face angle appropriate to the beach material and most s ignif icant wave type is s teeper than the overall shore profile. Steeper beach faces are associated w i t h coarser material and lower waves. Multiple ridges arise through continued shall owing of the offshore profile owing to abundant sediment supply, commonly associated w i t h a f a l l i n sea level’ or r i s e i n the land surface. Some sand beach ridges contain a h i g h porportion o f ’ w i nd-blown material . (Ref. #2)

5

BEACH WIDTH ( Z O N E ) : The horizontal d-lmension- o f a beach measured normal t o the shore 1 i ne. (Ref. #2)

BEACH ZONES: See beach wid th .

BEADED ESKER: An esker w i t h numerous bead1 i ke expansions and contractions i n w i d t h , strung out along i t s length. Eskers may be beaded a t s t i l l - stand positions (pauses i n g lacier re t reat) or where esker streams discharge into temporary lakes or pools o f standing water.(Ref. # 2 )

BEDDING PLANE: Tn sedimentary.or stratified rocks, the division planes which separate the individual layers, beds, or s t r a t a . (Ref. #l )

BEDROCK: The in-place materfal older than Quaterharj underlying the regolith i n depths ranging from zero, where the bedrock is exposed by erosion, to several hundred fee t . While commonly taken to imply hard rock, bedrock can actually refer t o any l i thological characteristic.

(Ref. #2)

BERGSHRUND: The crevasse whi,ch occurs a t the head of a cirque or valley glacier and which separates t h e moving glacier ice from ice attached to the rock wall. When no ice if attached t o the rock wall the gap between the wall and the glacier ice is : called the randkluft (German). (Ref. #3)

BIFURCATION: Fork-1.ike:separation of a water course i n t o two arms. (Ref. #Z)

BIRDFOOT DELTA: A del ta formed by the outgrowth of f ingers or pairs of natural levees a t the mouths of r iver d i s t r ibu tar ies making the d ig i t a t e or '"birdfoot" form typified by the Mississippi delta. (Ref. #7')

BOULDER CLAY: A term much used i n Britain t o denote ground moraine l e f t a f t e r the r e t r ea t of ice. The term ' t i l l I i s much bet ter , as many d,rift deposits called boulder clay contain no boulders nor are they always composed of clay. T h e i r composition depends upon their o r ig in .

(Ref. #3)

BOULDER TRAIN: Boulder trains take their origin from knobs or prominences of rock which lay i n the path of glacial adyance and gave off boulders readily and .abundantly to.'the overridikng l i ce . Such t r a i n s l i e i n the l ine 'of glacial movement, b u t the baulders are not carried forward i n s t r i c t l y para1 le1 'lines .. They may therefore appropriately be cal led boulder fans. The boulders are of a single k i n d , or a t l e a s t of the few kinds represented by the parent knob. They usually grow smaller and more worn as traced away from i t . They mingle . w i t h the underlying d r i f t and i n this respect di f fer from the boulder belts. (Ref. #1)

BRAIDED FLOODPLAIN: Floodplain which has had fluvial braided action a t some time e (See braided stream).

BRAIDED MELTWATER CHANNEL 'SCARS: Remnants of me1 twater channels forming a braided stream pattern. (See braided stream).

BRAIDED OUTWASH CHANNEL: Outwash channels forming a braided stream pattern. ‘UPJ (See braided stream) .

BRAIDED STREAM: A braided stream i s one t h a t flows in severdl dividing and reuniting, relatively wide and shallow channels resembling the strands of .a braid. The cause of such dividing is the continual obstruction and sh i f t ing of channels by coarse-grained sediment deposited by the stream. Where more sediment i s being brought to any p a r t of a stream t h a n i t can remove, the building of sand and gravel (and sometimes s i 1 t ) bars becomes excessive. The resu l t i s tha t the stream develops an i n t r i ca t e network o f interlacing channels. Braided streams commonly occur a ) i n senliarid regions having relat ively low re l ie f , where streams receive most of their discharge from higher mountain areas; b) i n areas o f active glacial outwash-plain and valley-train b u i l d i n g , where the sediment-laden meltwater i s derived from a melting glacier; and c) in the widened beds of mature streams i n mountain, piednlont and foothi l l areas i n arid, temperate, and periglacial regions. Stream gradients may be remarkably steep. The landscape of watersheds contributing surface runoff and sediment i s usually bare of vegetation or is only lightly vegetated. High surface runoff coupled w i t h easily available and abundant material causes entrainment of a large sediment load . Thus the production of a large volume of sediment i n drainage basins contri- b u t i n g sediment i s an important factor and any stream will braid i f the bed-material load exceeds a certain amount. There is also a close b u t contrasting relationship between braiding and meandering, w i t h the

j . gradient/discharge ratio being higher for braided streams. Aggradation of the channel bed and the lack of lateral control (ease of bank erosion) are factors t h a t induce braiding. With i t s higher gradient/ discharge ratio, the transported sediment tends t o be appreciably coarser (gravel, sand) i n braided streams t h a n i t i s i n meandering stream (sand, si1 t ) . Moreover, the upstream ends of longitudinal bars generally contain coarser , more poorly-sorted sediment. Discontinuous horizontal s t r a t i f i c a t i o n i s common. Forest beds and trough-fill cross- s t ra t i f icat ion character ize braided stream deposits. (Ref. $2)

w

CALVING: Breaking o f f and floating away as icebergs of l a r g e masses of a glacier that reaches the sea. (Ref. F 1 )

CARTOGRAPHY: (1 ) The science and art of expressing graphically, by means of maps and charts, the visible physical features of the earth’s surface, both natural and man-made. ( 2 ) The sc,ience and a r t of map construction.

(Ref. #1)

CHANNEL: (1) The deepest po r t ion of a stream, bay, or s t r a i t through which the main volume or current of water flows. ( 2 ) The par t of a body of water deep enough t o be used for navigation through an area otherwise

Channel. (4 ) Metal : A sow or runner. ( 5 ) A cut along the 1 ine where rock or stone i s t o be s p l i t . (6 ) Paleontol : A groove, such as the groove t h a t winds down the co?umella war i t s base i t 1 some shel ls arid ternlinates in the siphonal notch or in the cana l . (Ref. ;:1)

’ too shallow for navigation. ( 3 ) A l a rge s t r a i t , a s the..English

_ .

CHANNELLED TILL: T i l l a t t h k end of a receding glacier ( i .e . Lat . Morraine), tha t has been chanbeled i n stages by meltwater or streams r u n n i n g a1 ongside of glacikr and then a t the end of the ice r u n n i n g along the end face of the ice t o create channels perpendicular t o the ice movement.

CIRQUE: Tl:le amphitheatre shaped hollow a t the head of a valley, or edge of an upland, formed by nivation and glacial scour. Cirque i s French in origin b u t has generally superseded other terms such as cwm and corrie. (Ref. # 3 )

CLASTIC SEDIMENTS: Fragmentkd materials such as sand and gravel that are produced by the mechanical disintegration of a l l types o f preexisting rocks. ~ (Ref. #4)

CLAY: Soil fragmental material w i t h a particle size below 0.002 mm in ,diameter. Also, a group of crystalline minerals, colloidal i n s ize and composed.large1y of iron and aluminum s i l i ca t e s . ' . ' (Ref. #5)

COL : Pass formed where two cirques converge, cutting into the same wall and thus lowering i t below the level of , the, remainder of thebsummit area. (Ref. #4)

COLLUVIUM: A body o f sediment deposited by any process of mass-wasting or non- channel f low of wa,ter. Colluvium mainly consists of heterogeneous

"w' materials of any $ar t ic le s ize tha t accumulate on the lower par t s , a t the base of steep slopes. The sediment i s transported there by gravity, soil creep, sheet erosion, rai~wash, mudflow, or so l i f luc Along the margins of stream valleys, colluvium is l ike ly to in te r - finger w i t h alluvium and i t i s not always easy to distinguish between the two. ;Although colluvium i s characterized by nonsorted some sorting and poorly developed s t r a t i f i ca t ion may be seen.

(Ref. #2

or

i o n .

debris,

COMPOUND ESKER; As a resul4 of braided glacial stream action - one esker having

CUfOFF (SPUR): When along {he course of an entrenched r iver l a te ra l ero.sion becomes predominaqt, a spur projecting into a loop may ultimately be worn away a t ttie root, so that the r iver breaks th rough a t t h i s p o i n t and, abandoning i t s curved course, leaves an elevation isolated from the h i g h ground on efther bank which i s known as a cu off s u .

many i ntertwi n i ng larms . i

[Ref. !l!

COLLAPSED SUPERGLACIAL TILL: The topography created by collapsed superglacial or englacial t i l l may be. referred t o as dead-ice moraine, stagnation moraine, ice-disintegration features or moraine, or as collapse moraine. I t formed when englacial t i l l o r , more commonly, superglaciaj t i l l was l e t down enevenly as the underlying dead ice me1 ted, 'Such ablation t i l 1 is generally, though not necessarily, less compact, .coarser and more

w

'1 i

U washed and sorted than lodgement (basal) t i l l . Dominant depositional processes were slumping, mudflow (flow of t i l l and, possibly, some fine- grained s t r a t i f i ed d r i f t ) and other k i n d s of mass movement down ice slopes. The glacier topography was continuously changing as a r e su l t of different ia l me1 ting caused by the continually changing thickness of the superglacial' t i l l cover. The term also refers to the blanket of glacial materials i n s u l a t i n g stagnant ice. Where this blanket happened to be thinner, the ice melted more rapidly, forming a depression. Subsequently, some o f the adjacent t i l l slumped or flowed i n t o the resulting hollow, thickehing the blanket there and a t the same time t h i n n i n g i t on the surrounding ice. Accordingly, around the depression the ice then melted fas te r t h a n i t d i d i n the hollow. As a resul t , repet i t ious inversion of topography on the stagnant glacier ice surface resulted. This k ind of melting process gave r i s e t o the distinctive compositional and structural appearance of collapsed t i 11 sediment. (See ablation t i l l ) . (Ref. #2)

DEAD ICE MORRAINE: Collapsed superglacial and englacial t i l l (ab la t ion t i l l ) including subglacial drift thrust u p i n t o the glacier along compressive- flow sheer planes. Also called collapsed ablation t i l l , stagnation moraine, ice-disintegration moraine, stagnant-ice moraine, collapsed moraine, collapsed superglacial t i l l , collapsed superglacial mudflow, hummocky moraine, knob-and-kettle nlorain. The outstanding character- i s t i c of dead-ice moraine i s hummocky relief consisting of closely- spaced knobs alternating w i t h marshy kettle-hole depressions called sloughs or prairie potholes i n Western Canada. There is an almost complete lack o f streams and stream-cut Val 1 eys. The hummocky d r i f t , which may be several hundred feet thick i n some areas, generally obscures preexisting relief features. I n some areas the thickness of the d r i f t has been found t o be roughly f ive times the local available re l ief - - . t h a t i s , the height of hummocky knobs. Characterist ic- landforms associated w i t h dead-ice morraine include ice-walled lake plains; collapsed lake-sediment plains, collapsed glaciofluvial landforms and ice disintegration ridges and trenches. The ablation t i l l was responsive to slight changes i n superglacial topography and was continually slumping and flowing t o lower areas on the r o t t i n g ice . Ice i n these low! areas, insulated w i t h a thick layer of t i l l , me1 ted more slowly whilb the higher, newly-exposed ice melted more r ap id ly . T h u s , several inversions of topography may have taken place d u r i n g glacier melting. The f ina l resu l t was the hummocky topography character is t ic of dead-ice morraine. Domipant depositiona1,process were flowage and s l i d i n g . Contortion and disruption oT bedding i n collapsed- lake sediment indicate this. Flowage and s l i d i n g of ablation t i l l i s less obyious than i t i s i n collapsed stratified sediments. Only where the melt-out t i l l o r flow t i l l has been interbedded w i t h s t r a t i f i e d , washed d r i f t i s this or igin obvious. Mudflows were common along the sides of superglacial lakes. Where slope angles on hummocky moraine a re low (4 degrees or less), the ablation drift i s re la t ively t h i n .

' Where the slopes on hummocky dead-ice moraine are steep and the knobs are h i g h , a b l a t i o n d r i f t tends to be relatively thick. F l u i d i t y and p las t ic i ty o f the drift also controlled slopes on the sides of knobs and 'knolls. Higher moisture content and higher plast ic i ty resul ted iri lower maximum angles of slope a t which the d r i f t . could remain s table without s l i d i n g . See Abla t ion Moraine.and ablation Till.(Ref. #2)

.- .

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i h

DELTA: A'body,of sediment deposited by a stream f lowing into the standing water of ,a lake or the sea. The name i s derived from the sirni lar i ty of a de l t a ' s plan view to the triangular outline of the Greek cap i t a l l e t t e r del ta . As sediment i s deposited i n a de l ta ic environment , i t becomes easier for the river t o divide and flow to each side. Each new branch forms new banks, and these eventually divide and subdivide. I n th i s way, the 'main delta , as we1 1 as subdel tas , grow outward , and are characterized by a branching nework of main passes and smaller distributary channels. Small del tas may be formed where meltwaters discharge into a temporary glacial lake, where modern rivers enter a lake, or a t the confluence o f two r ivers -- especailly where a swift stream heavily laden w i t h sediment joins a much slower and more sluggish larger river. According to detai ls of their shape and origin, various types .of del tas can be recognized , such as arcuate, bayhead , birdfoot, cuspate , d ig i t a t e , esker, estuarine, fan, glacial , inwash, kame, lobate, outwash, t i d a l and washover deltas. Changes in the configuration and surface morphology of de l tas fa l l i n t q three categories: 1 ) those associated w i t h continuing deposition o f fl'uvial sediment, 2 ) those related to shore processes on the delta margin, 3) those affecting the surface of the delta generally. Fluvial deposition takes place a t the mouths of r ivers where horizontal accretion tends to prograde na tu ra l levees offshore as sedimentary j e t t i e s . Shoals flanking deeper outflow distributary channels indicate, the possible pattern of future growth of sedimentary j e t t i e s a s subaerial forms. Once established, they develop as natural levees and are bu i l t up and broadened by deposition from flgoduateys. Modern deltas display great variety i n size, shape, structure, composition ( c l a y , s i l t , sand , or gravel) , and genesis. The coarsest par t ic les set t le o u t f i rs t i n shallow-water channel beds and on levees, and the f inest sediments s e t t l e farther out i n slackwater and deep offshore waters. The m i n g l i n g of s a l t and fresh daters causes individual clay particles t o cluster i n t o larger aggregates. Some of the major factors that influence the character o f deltas include 1 ) geologic setting and sediment sources i n the drainage bas in , 2 ) climatic conditions i n bo th the drainage and depositional basin, 3 ) tectonic s tabi l i ty of the sedimentary basin, 4 ) gradient and reiime of the stream carrying sediment t o the delta, 5 ) depositional and erosional processes and the i r in tens i t ies w i ' t h i n the de l ta , and 6 ) t i d a l range and 0ffshor.e hydrologic cond i t ions . Many large

environments, yielding different textural and stratigraphic patterns. Among these a re l the environments of channels, including main passes; subaqueous and subaerjal levees, interdistributary troughs and mudflats ; marshes and swamps, freshwater lakes .and ponds; and crevasse splays.

I de l tas i n lakesland the sea show several distinguishable depositional

(Ref. #2)

DENDRITIC DRAINAGE: The pattern formed by insequent streams resembling the branch pattern of a tree. Usually formed on homogeneous rocks.

(Ref. #3)

DEPOSIT: Anything laid down. Formerly applied to suspended matter l e f t by the agency of water, b u t now made t o include a1 so mineral matter i n any fornl, and precipitated by chemical or other agencies, a s the ores, etc. , i n veins. ( 2 ) The tenn mineral deposit or o.re deposi t i s a r b i t r d r i l y used t o desiclnate a na tura l occurrence of a useful mineral or ore i n suff ic ient &tent and degree o f concentration to invite exploitation.

(Ref. i l )

w DIKE ( D Y K E ) : (1) A tabular body of ingenous rock that cuts across the structure o f adjacent rocks or cuts massive rocks. Although most dikes resul t from the intrusion o f magma, some are the result of metasomatic replace- ment. ( 2 ) A wall or mound bui 1 t around a Tow-lying, area t o prevent flooding. I (Ref. # l )

DRAINAGE CHARACTERISTICS: The hydrology and related features of streams,' lakes, swamps, marshes, and canals within an hrea. Includes consideration, in the i r seasonal aspects, of depths, widths, banks, bottom conditions, velocities, gradients, turbidity, sedimentation, temperatures, ice conditions and otqer pertinent related items. (Ref. # l )

DRAINAGE PATTERN: Geometric arrangement of stream segments i n a drainage system, generally related t o inequalit ies of slope, soil or rock type, s t ructure , and t o geological history. Among the many drainage patterns are the following: dendritic, trellis, parallel, radial, rectangular, annular, kettlehole, sinkhole or swallow-hole or kars t ic , thermokarst, lacunate, pinnate, phantom, barbed, assymetrical , colinear, beaded, distributory or dichotomous, braided, anastomosing, oriented lake, yazoo, contorted, meandering, deranged,reticular, ditch and t i l e . (Ref. #2)

. , .

DRIFT (GLACIAL): A collective term for a l l detr i ta l mater ia l der ived from a glacier. Includes . . both t i l l and stratif ied f luvioglacial material . '.

(Ref. $5)

" DRUMLIN: Stream1 ined , oval to elongated h i 11 composed largely of compact t i 11 formed beneath flowing ice and w i t h i t s long axes para1 1 e l t o the direction of ice movement. The end facing the direction of the ice f ront i s blunter and steeper than the downstream t a i l end, which tapers in plan and profile. Drumline vary i n height from 20 t o 200 f e e t (6 t o 60 meters) commonly 50 t o 80 f ee t (15 to 24 meters) , and in length from a few hundred f ee t t o several miles (100 meters to several k i 1 ometers) . (Ref. #2)

level of the sur&ounding ground. (Ref. #2) DRUMLINIZED TILL PLAIN: Low drumlinoid ridges w i t h ' ridge t ~ p s above the general

R U N E : ( 1 ) Geol: A low h i l l , o r bank, of drifted sabd. ( 2 ) Mounds and ridges of wind-blown or eolian sand are dunes. Once s ta r ted , a dune becomes an obstacle t o blowing sand, and the lodgement $of more sand causes the dune t o grow. In this way,.mounds and ridges of sand, c res

'. and sometimes even hundreds of f ee t high a re bu i l t by the wind. ?37 A mound , ridge , or hi 11 of w i nd-blown sand , e i ther bare or Covered W i t h vegetation. The term has been applied also to subaqueous features , b u t unless a suitable modifier is used w i t h the term, an 'eolian '

denotation i s assumed. (Ref. #1)

D U N E , LONGITUDINAL: See Longitudinal dune. \

. . I

DUNE TRANSVERSE : See 'traqsverse dune.

kdJ END MORAINE: Ridgelike accumulation of drift constructed a t the margin of an active glacier, u,sually around an individual ,lobe during a period o f re la t ive standsti'L11. I t i s a comprehensive term used t o designate elongate transverse, commonly gently curved, ridges or groups of sub- parallel ridges of d r i f t , 10 to 200 f ee t ( 3 t o 70 meters) h i g h t h a t mark the marg'ln'bf former valley glacier or ice sheet frontal positions. Typically, the ridges are long and narrow, often reveal an irregular surface, and may be locally discontinubus. Also called marginal morai ne, recessional moraine, or terminal moraine (end moraine a t the maximum advance of an ice sheet) . (Refs. f 2 )

EOLIAN :

ESKER:

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EXTRUSIVE

See Aeolian

A l o n g , narrow, commonly sinuous ridge composed of we1 1 - and partly- washed ice-contact granular d r i f t -- chiefly sand and gravel w i t h minor si1 t , ' cobbles , boulders, and ti 11 inclusions. Eskers may a1 so be composed almost wholly o f sand and s i l t w i t h and without a cover of boulders or ab la t ion t i l l . Because eskers are ice-contact deposits l e t down a f t e r melting of the supporting ice walls, they usually show complex irregular bedding and col lapse structures. Eskers may be depo- s i ied between ice walls by a stream flowing on (superglacial ) , within (englacial) , or beneath (subglacial) stagnant glaciers; b u t mostly they are deposited by sub glacial meltwaters flowing i n tunnels near the bottom of the glacier ice. Eskers may reveal every transition from an origin in an ice tunnel t o a lake delta. Some can be seen to go u p h i 11 and downhi 11 over minor features of the landscape. Eskers may exhibit reticulate, braided, branching, and dendritic patterns; b u t most commonly they occur as a single serpentine ridge. The higher and wider parts of eskers are often attended by el ongate troughs , kettleholes, associated kames, esker-delta beads, and localized o u t - wash expansions w i t h and without pitted (kettled) surfaces. Their sky1 ine may be nearly level or bumpy, passing oyer hi 11 s and through hollows. Strandlines on their f1anks"suggest temporary ice-margin or englacial ponding of meltwaters against the esker. Eskers vary i n height from seferal feet t o well over 100 fee t and from a hundred f e e t u p to many, miles i n length. They resemble abandoned winding railway grades. Because eskers commonly r i s e above the level of the surround- i n g land surface and normally contain sections of moderately we1 1 - sorted granular materials, they are frequently used as a source of construction material. The mean grain size of esker sediments increases progressively upstream. Sorting and s t r a t i f i ca t ion of these deposits can vary greatly over short distances from very good to very poor. (Ref. # 2 )

IGjYENOUS ROCK: Applied t o those .ig?enous rocks derived from magmas or magmatic materials ppured out qr ejected a t the earth 's surface, as d i s t inc t from the intrusive'or plutonic igneous rocks which have sol idif ied from magmas t h a t have been injected into older rocks a t depth without reaching the surface. Syn: Effusive rocks, volcanic rocks. (Re f . = I )

W

FAULT: ' A P l

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fracture i n the & u t of the earth along which there has been dis- acement of the two s ides re la t ive to one another. (Ref. # l )

FLOODPLAIN: 1 ) Flat land bordering a stream and subject t o periodic flooding by the'stream. Two o r more levels of flooding may be present. 2 ) T h a t f l a t - l a n d bordering a stream which is being constructed by the deposit- i onal proqesses ofi the present stream, and i s not therefore a terrace ( q . v . ) . In this sense, a floodplain may be re la t ive ly 'ac t ive -- say, flooded once every: one or two years; or virtually inactive -- say, f1ool;led only once /?very ten or twenty years -- in ' which case it may be referred to 'as a lbw terrace, inactive high-level floodplain b r , less commonly, a fossil! f loodplain. Frequency of flooding suggests an inter- relationship among, the height of a floodplain, the thickness of overbank sediments, and the!,geometric and hydraulic characteristics of the stream that b u i l t the floodplain. In most places, local relief of the inactive floodplain consists of widely spaced channels of tributary streams and vestigal channel-like landforms. Relatively flat interchannel areas are formed by repeated flooding and overbank deposition, the increments of which commonly tend t o be thin (small fractions of an inch), patchy i n d i s t r i b u t i o n , and re la t ively f ine ( f ine sand, s i l t , c lay) i n texture. The role of vegetation in floodplain deposition and the resulting surface configuration may also be important. In general, the texture of surface materials composing floodplains decreases with increasing distance from the stream channel. Somewhat coarser-textured materials tend to occur more extensively nearer the stream channel. The proportionate extent, however, depends importantly on local conditions of f l o o d i n g and the character of the sediment load. Thick floodplain deposits show rough s t r a t i fd . ication of soil textures, w i t h the coarsest materials usually i n the base ,of the sediments (substratum) , including coarse sand and gravel and possibly even quite large boulders and progressing to finer soi 1 textures a t and near the ground surface (topstratum) , .where clay, s i 1 t , and f ine sand predominate. Floodplain sediments are commonly s t r a t i f i e d i n more or less horizontal layers of similar textural comptis8tion. Also,-however, the?( may appear as a ser ies of overlapping and i nterf i ngering 1 enses h a v i n g different textural characterist ics. These materials may show ei ther poor or good sorting. There i s a general relationship.between meandering and braided patterns o f stream channels i n floodplains and t h e i r s t r a t - i f ied and lenticular structures. Braided channel deposits are generally coarser (sand, gravel , cobbles) than the deposits of freely meandering streams, b u t . t h i s a l s o depends on stream gradient and s ize of sediment available for transport. Coarser textures tend to concentrate toward the base of r i ve r ' ba r s and a l l u v i a l f i l l s , w i t h f iner sediments occurring toward the top and toward the outer edges of the active channel and i t s floodplain. The r a t e o f channel movement i s related to bank s t a b i l i t y , which i s partly a function of the texture of the underlying a l l u v i u m . Cohesionless granular alluvium, for example, i s easi ly eroded and gener- a l l y forms more unstable banks t h a n uniform, cohesive, s i l t y and clayey alluvium having a higher shear strength. Stream banks and beds w i t h a large proportion o f s i l t and c l ay , a re cohesive and so tend to r e s i s t erosion. Streams w i t h cohesive banks have qarrower widths and higher banks t h a n streams flowing i n cohesionless sediments of clean sand and gravel. In other words, where the a l luv ium i n the beds and banks of floodplains is sandy, or composed of sand and gravel w i t h a low content of s i 1 t and clay, stream .channels tend t o forin wide and shallow cross

.A, . :

sections and t o have relatively steep gradients. Sediment accumulation from overbank flooding and deposition seems t o be a re la t ively minor component that adds t o the height of a floodplain -- probably seldoul accounting for more than 102% of i t s thickness , w i t h 90% or more being contributed by the bedload i n the bottoms of sideways-shifting stream channels. The overbank flood deposits are found mainly i n the topstratulll of floodplains and are referred t o as vertical-accretion deposits.. They are usually finer i n grain-size than any associated lateral-accretion deposits -- for instance, p o i n t bars. The coarser fraction of the load in , t r ans i , t produces braided elongate river bars and consists chiefly of bedload deposits occurring below the active floodplain and beneat'h the f ine r topstratum deposits of inactive floodplains. Where the channel has s table banks, la teral channel movement is re la t ively slow and repeated additions of the overbank deposits are responsible for the development of natural levees whose textures vary from sand to clay, depending on regional geomorphic and hydrologic set t ings, b u t generally becoming f iner i n a downstream direction. Another source o f sediment$in the.more remote I

areas of wide vertical-accretion floodplains comes from tributary flooding ( l a t e ra l ly away from the stream). In many places this source of sediment may be a f a r more important factor i n modifying the floodplain surface than floods from the parent, or main, stream. The finer texture of surface deposits (topstratum) of the inactive floodplain, especially the more

.remote locations of extensive floodplains, means that th is zone has rela- t ively poor surface and subsurface drainage. These regions are variously called backswamps, slackwater flood basins, ponded backlands, and marshy lacustrine basins. (Ref. $2)

FLOODPLAIN MEANDER SCAR: A c lass of scars which includes any and a l l features on a floodplain t h a t mark the former course of a stream meander. They may be very fa in t ly t o very strongly expressed in the microrelief.

(Ref. #2) . .

,r. . . ,',,-. ..,,x r, , .: , . *%,A .. .

FLUTED TILL PLAIN: or Fluted Surface of a T i l 1 Sheet: S t r a i g h t , closely .spaced, - , > . ,:

narrow parallel ridges, 5 to 30 f e e t (1.5 to 9 meters) h i g h alternating w i t h f l a t , evenly-bottomed furrows. The ridges have accordant tops and are mainly developed i n t i l l , b u t may be found less commonly on other glacial d r i f t sediments, called fluted d r i f t . (Ref. #2)

FLUVIAL: O f , or pertaining t o , rivers; growing or l i v i n g i n streams or ponds; produced by river action , as a f l u v i a l plain. (Ref. #1)

FLUVIOGLACIAL: See Glaciofluvial. I

FLUVIOMARINE: Pertaining to the combined actions of r ivers and the sea. For example, deposits formed a t the mouths o f rivers entering the ocean.

(Ref. #2)

GLACIAL DEPOSITS: A mass of generally unconsolidated earth materials deposited -

di rec t ly by a glacier or indirectly reworked by i t s meltwaters. Such material was originally picked up and carried along i t s p a t h by the glacier. Generally, glacial deposits decrease progressively i n thickness far ther back from the edge of the ice. The term i s used t o designate bo th t i l l and stratif ied druft . Therefore, i t i s commonly used as a synonym for g lac ia l d r i f t . (Ref. #2)

1 4

GLACIAL GROOVE: A large furrow cut by the abrading action of rock fragments contained 3 n a glacier. (Ref. #1)

GLACIAL TROUGH: U-shaped valley shaped by glacial erosion. (Ref .. #2)

GLACIER: A mass of ice w i t h def in i te i la te ra l l imi t s , w i t h motion i n a def ini te direction, and originating from the compacting of snow by pressure. Moraines are not diagnostic, and the definition should not include those masses of a rc t ic i ce which, by reason of the i r low temperature, are fixed i n position. In Alaska, flood-plain icing or masses of ground ice.

(Ref. #l )

GLACIOFLUVIAL DEPOSITS: Deposits formed from water on, i n , or under a ,g l ac i e r as we1 1 a s . beyond the glacier terminus by me1 t-water .' (Ref. #4)

GLACIAL TILL: See ti7 1.

GLACIAL OUTWASH: See outwash.

I

GLACIAL LAKE: A lake fed predominantly by glacial !meltwater or a lake i n a depression i n par t cliosed by glacial ice. Includes proglacial lakes not directly adjacent ' t o the glacier and lakes lying against or on a glacier and fed mainly by waters derived from melting of a glacier. Depending on . the i r posit ion w i t h respect to the glacier, glacial lakes may be classified 'as proglacial, extra-morainic, ice-dammed, glacier- margin, or superglacial (supraglacial). (Ref. #2)

GRANITE: 1 ) A plutonic rock consisting essentially of alkalic feldspar and quartz. Sodic plagioclase, usually oligoclase is commonly present i n small amounts and muscovite, b io t i t e , hornblende , or rarely pyroxene may be mafic constituents. 2 ) Seismol : A rock i n which velocity of the compressional wave l ies somewhat between 5.5 and 6.2 km/sec. 3 ) Loosely used for any light-coloured, coarse-grained igneous rock. (Ref. #1)

GRANITE GNEISS: 1 ) a coarsely crystalline, banded metamorphic rock of granite composition. 2) A primary igneous gneiss o f granite composition.

GROUND MORAINE: A f l a t t o undu:lating moraine o f low re1 ief w i t h cl osed depressions and without pronounced transverse elements b u t w h i c h may show 1 ongi tud- i nal ly arranged stream1 i ned flow features oriented i n the direction of glacier advance. This definition distinguishes ground moraine from end moraine and from high-relief hummocky disintegration moraine. Ground moraine is thought t o have been accumulated largely a t the bottom o f a glacier , consisting of nonsorted and nonstratif ied drift materials frozen i n the bottom of the ice and pushed along i ts bed -- i.e.;accumulated

' beneath the glacier. When the glacier melts, such t i l l material is commonly dep.osited i n a re la t ively t h i n , irregular sheet over the area formerly occupied by the glacier. Ground morai ne i s a general term for any nearly f l a t o r undulating accumulaticm of chiefly subglacially- deposited lodgement t i l l . However, i n many places ' the lodgement t i l l may be overlain by a continuous to discontinuous surficial layer o f ab la t ion t i l l , commonly up t o 20 feet thick. Ground moraine therefore connotes a certain topographic aspect as wellras primarily subglacial accumulation o f t i l l sediment. I t shold not be used as a synonym for glacial t i 11 . (Ref. #2)

GULLYING: The erosion of soi 1 resulting from the excavation of trenches greater than 2 to 3 f ee t i n depth. (Ref. #5)

HANGING VALLEY: A valley having a floor higher than'the valley or shore i n t o which i t leads. Hanging valleys are usually formed by glaciation.

I (Ref. #4)

HUMMOCKY MORAINE: Area of glacial knob and ke t t le topography; may have been produced by ei ther live or dtagnant ice. (Ref. #1)

IGNEOUS ROCK: Formed by sol idif icat ion of hot mobile material termed magma. (Ref. #1)

INTRUSIVE ROCK: A rock t h a t consolidated from magma beneath the surface of the earth. (Ref. #1)

KAME : T ) A conical h i l l or short irregular ridge of gravel or sand deposited i n contact w i t h glacier ice. 2 ) Kames i s a Scotch term applied to assemblages of short , conical, often steep hils , b u i l t of s t r a t i f i ed materials and interlocking and blending'in the most diversified manner. 3) A mound composed bhiefly of gravel or sand, whose form i s the r e su l t o f original deposition modified by se t t l ing d u r i n g the melting of glacier ice against or upon which the sediment accumulated. 4) A h i l l of s t ra t i f ied dr i f t deposi ted, usual ly as a steep alluvial fan, against the edge o f an ice sheet by debo ching streams of sediment- 'laden nieltwater. 5 ) A low, steep-sided Y hi l l of s t r a t i f i e d d r i f t , formed i n co.ntact w i t h glacier ice. (Ref. #1) w I

KARST TOPOGRAPHY: In Karst, on the eastern side o f the Adriatic Sea, the lime- .stone rocks are so honeycombed by tunnels and openings dissolved out by 'ground waters, that much of the drainage i s underground. Large sinks abound, some of them f ive or six hundred f e e t deep. Streamless Val1 eys are common, and val leys containing streams often end abruptly where the l a t t e r plunge into underground tunnels and caverns, sometimes to reappear as great springs el sewhere. Irregular topography o f . this k i n d , developed by the s o l u t i o n of surface and ground waters, is known as karst topography, a f t e r the type region i n Yugoslavia and north- eastern I taly . (Ref. #1)

melting out of a mass ov underlying ice. Many kettles are steep-sided bowl-shaped depressions resembling a ke t t le drum i n form. Commonly 10 to 100 f e e t deep and 100 to 500 feet across , they tend to be more classical ly developed and thus better expressed i n deep and extensive ice-contact and outwash sediments than i n t i l l , i n which they commonly

' 'Occur. Kettles may be formed from projecting ice masses, from wholly buried small or extensive bodies of ice , and from floated-in or dropped- i n chunks of ice. Kettleholes may be drained or undrained, and the larger ket t les may be occupied by lakes, ponds marshes or swamps. Coalescing ket t les and kettle chains are quite common i n some areas. Extensive outwash-plains dot ted w s ' t h ket t les are called p i t ted outwash plains. In many places i t appears t h a t the pitted, or kett led, outwash, sediments were deposited on top of a more or less continuous sheet of stagnant i-ce o f variable thickness. Isolated blocks of ice persist longest i n

KETTLE: A sharply outlined closed depression i n glacial d r i f t created by the

16

pre-existing depressions, as buried preglacial , interglacial , and inter- stadial valleys. The occurrence of elongated valley-like kettles and long l ines of ket t les may be the reflection of buried drainage features -- valleys i n which the ice lasted longer than elsewhere: (Ref; #2)

on the bed of a lake. (Ref. #2) LACUSTRINE: Pertaining to lakes. The sedimentary deposits laid down under water

LACUSTRINE PLAIN: Many former lakes hive become extinct. Extinct lakes are recognized by various features. If a lake basin became ext inct by having i t s basin f i l l e d , the former area of the lake is marked by a f ? a t covered w i t h deposits such as are formed i n lakes. These deposits may be of gravel or sand along the shores, b u t the materials deposited f a r from shore are f ine. Such a f l a t is a lacustrine plain. A lacustrine p l a i n is a minor type of p l a i n , and may 1 i e in mountains, on plateaus or on plains of a larger type. (Ref. #1)

LATERAL ACCRETION: Wherever a stream meanders, i t d i g s away i t s outer bank while the inner i s bu i ld ing up the water level by the-deposition of material b r o u g h t there by rol l ing or pushing along the bottom. This is la te ra l accretion. If the stream i s subject to overflow, sediment must s e t t l e from suspension i n beds conforming to the surface. This i s vertical accretion. (Ref. #1)

LATERAL MORAINE: 1 ) Certain aggre ations o f d r i f t which a r e l e f t by a valley glacier after melting. 2 3 An elongate body of d r i f t , commonly t h i n ,

margin of the glacier. 3 ) An end moraine bui l t along the la teral margin of a glacier lobe occupying a valley. First used by Louis Agassiz.

(Ref. # 7 )

LAVA : Fluid rock such as that which issues from a volcano or a f i ssure i n

~ d A lying on the surface of a glacier i n a valley, a t or near the lateral

the earth's surface; also the same material solidified by cooling. I (Ref #1)

LAVA FLOW: 1 ) A stream or r iver of f l u i d or viscous or solidified fragmented lava which issues from an individual volcanic cone'or from a f i ssure i n relatively quiet fashion, w i t h l i t t l e o r PO explosive activity. 2 ) The sol idif ied, s ta t ionary mass o f rock formed when the lava stream congeals. Lava flows, are generally tabular igneous bodies, t h i n comp- ared t o their horizontal extent, and elongated i n the main direction of flow., Their form and internal structure depends chiefly on the f luidi ty of the lava, which , i n turn, i-s a function of composition. . Thus basic lava flows, such as basalt, are usually highly mobile, and flow for great distances, whereas s i l i c ic l avas , such as rhyolite and trachyte, are ordinarily sluggish i n their flow, commonly fragmented, and remain heaped u p , often i n steep-sided volcanic domes or i n short , steep- sided flows known as coulees. ! (Ref. #1)

17

L E V E E : I ) The raised banks b u i l t by a r iver i n time of flood. 2 ) Ar t i f ic ia l ly b u i 1 t or rai sed stop banks . , (Ref. #3)

LIMESTONE: A sedimentary rock composed predominantly of calcium carbonate (CaC03). If dolomite (CaC03. MgC03) is present i n appreciable quantities, i t i s called dolomitic 1imes.tone. I t may have an organic, chem-ical, biochemical , or mechanical origin. (Ref. #2)

LOESS: A homogeneous , nonstratified, unindurated, ye1 lowish to buff-coloured windborne deposit consisting predominantIy o f si1 t-sized particles w i t h subordinatte amounts of f ine sand and clad, porous and permeable, w i t h a rude vertical parting common i n many places. Typically this uniform, s i l ty eo l ian material has an open s t ructqre , re la t ively h i g h cohesion due to cementation w i t h clay or calcareous material a t grain contacts, and stands i n near ly ver t ical c l i f fs or bluffs owing t o numerous t iny, vertical tubes" 1 ined w i t h calcium carbonqte, thought t o be the casts of grass stems and root le ts . Loess is commo;nly derived from the s i l ts of deserts, glacial outwash or glacial-lake ;deposits, and extensive floodplains i n proglacial arid environmeFts. ,Three facies of. true loess may be observed: 1 ) upland loess of eolian qrigin (d i rec t wind. deposition), 2 ) slope loess i n which the original loess has been washed down slopes and therefore has been reworked by col1 udial processes , and 3 ) 1 akebed swamp or Val ley-floor 1 oess i n which the ~wi ndborne si1 t has been depo- s i ted i n lakes .or swamps. Thick loess p4ckets are composed of a cyclic succession of members. The loess layers'ithemsleves are from 1 to 5 meters thick, nonstratified or very f ine ly s t ra t i f ied , a l te rna t ing w i t h layers of fossil soil (paleosols), slopedash or solifluction materials, and even minor sand or gravel. In typical loess , moderately well -sorted , loosely coherent grains between 0.01 to .05 mm i n diameter form the dom- inaqt grain-size fraction. Between 40 a d 50% by weight represents the mean abundance of this size. fraction. T 3 ,pica1 loess contains some 5 t o 30% clay-sized particles below 0.005 mm and 5 to 10% of sand-sited par t ic les above 0.25 mm. Many loess deposits contain 80% grain sizes between 0.01 mm and 0.1 mm. Typical loess is distinguished from loess- 1 i ke deposits such as sandy loess , 1 oess ,loam or adobe , and clayey loess. Loess and loess-l ike deposits ard fairly often classified accord- i n g to their genesis i n combination w i t h 'a c lass i f icat ion according to grain size. i (Ref. #2)

l MARGINAL MORAINE: Generally appl ied t o present-dad glaciers and t o mountain

Val 1 eys occupied by a1 pine, or Val ley, gliaciers Marginal morai ne are formed a t the margin of g1acier.s and incl'ude cross-Val ley, 1 ateral , and. end moraines. . , (Ref. #2) !

MASS MOVEMENT: (Mass wasting) Involves the bul k tqansfer of rock debris and soi 1 down slopes under the influence of gravity. I , (Ref. #3-)

MASS WASTING: See mass movement.

MATURE ( O L D ) STREAM: A c lass of streams that have bstablished f lat gradients and that are subject t o l i t t l e i f any further; downcutting. (Ref. #2)

\.

28

,-

bid

U

MEANDER: 1 ) One of a ser ies of somewhat regular and loop1 i ke bends i n the course o f a stream, developed when the stream is flowing a t grade , t h rough 1 ateral shif t i ng of i t s course toward the convex sides of the original curves. 2) A land-survey traverse. a1 ong the bank of a permanent natural body of water. (Ref. #1)

MEANDER SCAR: Usually shaliow, crescentic stream-made cuts i n the inactive floodplain bordering a stream. (Ref. #2)

MEDIAL MORAINE: 1 ) Whenever two mountain glaciers bearing la teral moraines unite the lateral morai nes belonging to the two margins which coalesce give r ise to medial moraine. 2 ) An elongate body of d r i f t formed by the joining 'of adjacent lateral moraines below the juncture of two valley glaciers. First used by Louis Agassiz. (Ref. #1)

MELTWATER: Water result ing from the melting of snow and glacier ice. (Ref. #2)

MELTWATER CHANNELS: Flow channels as a r e su l t of meltwater action.

METAMORPHIC ROCK: Includes a l l those rocks which have formed i n the s o l i d s t a t e i n responsd to' pronounced changes o f temperature, pressure, and chemical environment, which take place, i n general , below the she1 1s of weathering and cementation. (Ref. #1)

MORAINE: 1) An accumulation o f drift o f initial constructional topography, b u i l t w i t h i n a glaciated region, chiefly :by the direct action of glacier ice along i ts margin, and usually having an uneven surface topogyaphy w$th closed depressions. 2 ) Also used for accumulations of glacial d r i f t , i n transport on a glacier 's surface i n la teral and medial morai ne .posit ions on a Val ley or rnountai n glacier, or i p a general marginal position on an ice sheet, and i t s out le t g laciers . There are several kinds of moraine whose pattern and character of mounds, ridges, and depressions as well as their ' inferred posit ion relative to the ice provide a means for classifying and naming them. Sometimes erroneously used as a synonym fo r t i 11 a (Ref. #2)

cover o f det r j tus 'and so i l . (Ref. #1) OUTCROP: The exposure o f bedrock or strata projecting through the overlying

. .

OUTWASH DELTA: A mass of .outwash depo'sited into a body of s t i l l waterg as a pond, lake, or the ocean. Opposite-to inwash de l ta , which is non- glacial i n . o r i g i n . (Ref. #2)

OUTWASH PLAIN: A body o.f outwash tha t forms a broad plain a t and beyond the margin or former margin of a shrinking glacier and commonly consisting o f a number of coalescing outwas h fans. 'Varieties .are call ed ou twash terraces, fans, aprons, trains, or. sandur. Outwash sediments usually show cross-bedded units composed of sharply a1 ternating sand and/or gravel grain sizes a Typically gravel i s deposited closest t o the glacier margin and. grades downstream' into more extensive areas of sand.

. ! . Nonpittqd.., , (.nonkettl,,ed,)* .outwash plains are nearly level , have gentle gradients, and may or may not be channel-scarred. Blocks of ground ice, f loated-in ice, and, buried sta:gnant ice masses eventually melt out to produce a pitted outwash plain. Extreme p i t t i n g (kett lehole

19

depressions) suggests deposition over stagnant ice havi,ng an irregular thickness. Many outwash plains are also terraced. Called outwash- deltas when b u i l t into lakes. (Ref. #2) 3

OUTWASH TERRACE: Sirhilar to r iver terrace only developed- through glacial outwash material and actions. (See r iver terrace)

OVERBURDEN: Material of any nature, consolidated or unconsolidated, that overlies a deposit of useful materials, ores, or coal, especially those deposits tha t a re mined from the surface by open cuts. (Ref. # 1 )

OXBOW: 1 ) A crescent-shaped lake formed in an abandoned r iver bend tha t has become separated from the main stream by a change i n the course of the river, usually by the stream:.cutting through a narrow neck. 2 ) Any curved lake occupying a cut-off meander loop. Overbank f loods add clay, s i l t , and f,ine sand to stagnant waters i n the oxbow lake, f i r s t i n the limbs next to the flooding river, ultimately filling the lake and converting i t t o a marsh and then into a clay plug; a tough and res i s tan t body composed chiefly of organic fPne-grained sediment i n t o which any future channel of the stream commonly erodes w i t h d i f f icu l ty .

(Ref. # 2 )

' PARENT MATERIAL: The horizbn of unconsolidated and weathered rock material from

PATTERNED GROUND: A term for minor and microrelief land' features, as circles ,

which soil is made, (Ref. #5)

polygons, nets, steps and s t r ipes , charac te r i s t ic of b u t not confined to,areas now o r a t sohe previous time subject to intense frost action. In some of these 'features, the finer and coarser materials are sorted into various polygonal forms of varying dimensions w i t h angular stones around the perimeter and finer materials i n the centre. This action also applies to sorted or stone circles, nets, steps and s t r ipes . Patterned ground also includes nonsorted forms, as polygons out1 ined by vegetation zones, and s tep- l i ke forms on 'slopes. Such features have several possible origins. Some investigators include earth hummocks, tussocks, a variety of solifluction lobes,, terraces and s t r ipes and patterned fen i n the term patterned ground, w h i c h i s a l so used as a general term for polygonal f issures caused by desiccation i n an arid or semi-arid climate, Patterned ground has! thus become a general term, and i s n o t confined t o landform features: i n areas of permafrost or the periglacial environment. (Ref. #2)

PERIGLACIAL: Refers to areas, conditions , processes, and deposits adjacent to the margin of a glacier. (Ref. #1)

PITTED (SALT) PLAIN: An outwash plain of gravel a.nd sand or chiefly sand w i t h . . many kettleholes. Also, a limestone plain w i t h numerous small or large

closely spaced sinkholes. (Ref. #2)

PLUCKING: 1) Monoliths up t o many f e e t i n diameter, bounded by structural surfaces , are l i f ted .from the rock by the flowing ice and removed. This process has been termed plucking , and a l so quarrying. 2 ) The process o f erosion, by glaciers and streams whereby blocks are removed bedrock,along joints and s t ra t i f icat ion surfaces . Quarrying.

(Ref. ,

from

20

RADIAL DRAINAGE: A drainage pattern i n which the streams diverge from a central e'ievated tpact. (Ref. #3)

w RAISED BEACH: Sand and gravel ridges elevated above the present level of the lake

or sea i n khich i t was formed and indicating a change in the relative level of land and water surface. Raised beaches also mark the former shoreline of extinct lakes, many of them o f Pleistocene age. Also referred to as an abandoned beach. This term is preferred because i t does no t imply a raising of the land surface, which is not necessarily the cause o f a beach having been abandoned. (Ref. #2)

REGOLITH: The mantle of loose material consisting of soils, sediments, brocken rock and weathered debris overlying the s o l i d rock of the earth.

(Ref. #3)

'RIVER-CUT bANK: Material cut by fluvial action t o create steep-sided banks.

RIVER TERRACE:, A river terrace consists of a plain and an accompanying escarpment. The 'teri-ace plain is approximately horizontal and usual ly slopes b o t h w i t h the grade of the stream and away from the river bed which i t faces. On the side toward the stream the plain i s bounded by an escarpment, the two together making the terrace; the opposite side of the plain i s usually bounded by more elevated land, either an older and higher terrace or the true Val ley wall. (Ref.. #1)

ROCHES MOUTONNEE: A g lacial ly molded rock outcrop having a smooth, gently sloping, /

rounded upstream side, the resu l t of abrasion, and a steep rough ' irregular downstream s i de, the result of pl ucki ng . . Roches mou tonn6e may be distinguished from crag-and-tail hills by the lack of a tapering, stream1 i ned t a i 1 composed of 1 odgement t i 11 or of sof te r bedrock.

w

( R E f .. #2)

ROCK GLACIER: 1 ) A lobate steep-fronted mass of coarse angular rock debris extending from the front of c1,iffs i n a mountainous area. Down.slope movement of the mass i s aided by i n t e r s t i t i a l water and ice. 2) A tongue1 i ke body of boulders resembling the appearance of a small Val ley g l a c i e r , which moves slowly down-valley under the influence of ice between the soil and rock papticles. (Ref. #2)

SAND DUNE: See dune.

SANDSTONE: A cemented or otherwise compacted de t r i t a l sediment composed Predominantly of W r t z grains, the grades of the latter being those of sand. Mineralogical varieties such as feldspathic and glauconitic sandstones are recognized , and al so argi 11 aceous , si 1 iceous , calcareous, ferruginous, and other varieties according to the nature of the b i n d i n g

. or cemenking material. (Ref. #1)

SCHIST: 1) A well-foliated metamorphic rock in which the component needlelike or flaky minerals, as mica, a re d i s t inc t ly v i s ib le . 2 ) A metamorphic crystal l ine ' rock having a closely foliated structure t h a t can be d iv ided along, approximately parallel 'planes of weakness and differing from gnei sses i n containing no essential feldspar and usually hav ing ; f iner lamination. Biotite and hornblende a re c mmon minerals of schistose rocks . 0 (Ref. #2) w

21

w

SCREE: A p i le of rock waste a t the base of a c l i f f , usually, a sheet of coarse angular rock debris m a n t l i n g the steep sides of a mountain slope or the base of an. escarpment. Normally the coarsest material is found a t or near the bottom of scree-forming slopes. All sizes of debris may be present. Scree deposits commonly r e s t a t an angle of about 35O, and may be remarkable uniform i n s ize of mateu'ial. Synonymous w i t h talus.

(Ref. #2)

SEDIMENT: 1 ) Solid material settled from suspension i n a liquid. 2 ) So l id material , both mineral and, organic, t h a t i s in suspension, i s being transported, or has been moved from i t s s i t e of o r i g i n by air , water, or ice , and has come t o r e s t on the earth's surface either above or below sea level. (Ref. # 2 )

SEIF DUNE: 1) The individual seif dune has a form very l ike t h a t of a sand dr i f t behind a rock. Its length or axis lies in the direction o f the prevailing wind, and i t s long c re s t i s a knife-edge ridge, one side o f which i s rounded and the other falls abruptly as a collapsing front which faces a direction a t r i g h t angles to , the l ine of the dune and t o the prevailing wind. The side on whichkithe front occurs depends on the s i d e . t o which the w'ind has temporarily veered o u t of i t s prevailing direction. The whole aspect of a seif( dune may therefore change w i t h i n a few. days. 2 ) Longitudinal dunes, oriented i n the direction of wind movement, and of great height and length. I (Ref. #1)

'SHALE: ' 2 ) A laminated sediment in which the constituent particles are pre- dominintly o f the clay grade. 2 ) Shale includes the indurated, laminated, or f i s s i l e clay-stones and s i l ts tones. The cleavage i s t h a t of bedding and.such other secondary cleavage or f i s s i l i t y t h a t i s approximately para1 le1 t o bedding. The secondary cleavage has been produced by the pressure of overlying sediments and p l a s t i c flow.' (Ref. #1)

SILT: A soi 1 textural class having par t ic le s i Tes between 0.002 and 0.05 mm in diameter. (Ref. #5).

waters escape t o the underground. The saucer-shaped t o funnel-shaped depressions are created by solution of ,soluble rocks, as limestone, dolomite, gypsum, and hal i te . ' Sinks are usually connected w i t h underground solution cavities, caverns, and channels and may resu l t from subsidence following underground solution. (Ref. #2)

SINK HOLE: A surface depression i n karstic limestone terrane th rough which surface

SLIDE: A relatively deep-seated failure of a slope. Three main types can be identified. A block flow sl ide resul ts from internal deformation leading to fa i lure of a hard jointed rock mass, g i v i n g r i s e t o the

I sliding of blocks and pulverized material t o the bottom o f the slope. A plane shear slide results from the presence of a plane of weakness, as a f au l t , j o i n t , f o l i a t f m , bedding or soft layer in a cr i t ical or ient- ation withiwthe slope causing the faulted materials t o move down slope or shear along this plane. A .rotational shear slide results from the yjelding and redistribution o f shear stresses in a soil or sof t rock mater.ia1, causing a more or less rotational movement or shear and a

22

circular surface of failure. Slides are landslides for which significant shearing resistance exists along a shear surface. Slides may involve few or many ind-ividual units or blocks , either bedrock or soil materials, rotational or planar types of fa i lure , and very l i t t l e or considerable break up a f t e r movement develops. Ref. #2)

saturated w i t h ' water. 2) The slow downhi 11 flow o f surface deposits saturated; w i t h water re,leased by thawing. Mostly 1 imi ted in usage t o such movements i n permafrost or periglacial regions. (Ref. # 2 )

SOLIFLUCTION: 1 ) The process o f slow downslope flowage of unconsolidated material

SPILLWAY: An overflow'channel for flood water, particularly over a dam. (Ref. #2 )

STEPPER BANK CUTTING: Downward cutting of single bank a t different stages, yielding 'a stepped characterist ic.

STRATIFICATION: A structure produced by deposition of sediments in beds or layers ( s t r a t a ) , laminae, lenses, wedges, and other essentially tabular units. The layered arrangement of constituent particles in a soil or rock body.

(Ref. #2)

TALUS: 1 ) Coarse, .angular fragments o f rock and subordinate soil material dislodged by weathqring (temperature and moisture changes) and collected a t the foot of c l i f f s and other steep slopes and moved downslope primarily by the pull of gravi ty , 2 ) The apron of :coarse rock waste sloping outward from the c l i f f t h a t supplies i t . ;Thus, the term may refer

landform containing the accumulated gravity debris. Synonymous with scree. (Ref. 62)

w ei ther t o a type of material (coarse, angdlar pieces of rock) or t o the

TARN : A small mountain lake or pool , especial ly one occupying an i ce-gouged basin on the floor o f an abandoned cirque. (Ref. #2)

TERRACE: Beaches and terraces are relatively f lat , horizontal , or genkly inclined surfaces, sometimes long and narrow, which a r e bounded by a s teeper ascending slope on one side and by a steeper descending slope o n the opposite side. Both forms, when typicallydeveloped, are steplike in character. (Ref.#l)

THERMOKARST: A1 1 re l ie f forms -- as lakes, ponds, p i t s and other depressions w i t h and without peat and water -- produceg by se t t l ing or caving of the ground surface as a resu l t of the melting of ground ice i n the upper part of a permafrost. Thermokarst mkans thermal solution or, more precisely , thermal me1 t i ng . (Ref. #2)

TILL PLAIN: An extensive, more or less featureless, low-relief sag-and-swell morai nal deposi t. (Ref. #2)

23

i

TRANSVERSE D U N E : A strongly asymmetrical dune ridge extending transverse t o the e direction of dominant sand-moving winds; the leeward slope stands a t or near the angle of repose of sand i f the dune i s active, while the windward slope i s comparatively gentle. (Ref. #1)

TRELLIS DRAINAGE: A. drainage pattern i n inclined stratif ied rocks in which the streams trend para1 le1 t o the s t r ike fo r long distances and then turn sharply to cut transversely through intervening ridges, resembling a garden t r e l l is. See drainage pattern. (Ref. #2)

TRUNCATED SPUR: The widening of a stream Val 1 ey by a glacier resul ts i n the

! (Ref .#1) truncation of the spurs which extend i n t o i t from the two sides.

UNCONSOLIDATED SOIL DEPOSIT: A deposit that i s no& fully consolidated under i t s exis t i ng overburden pressure.

gradient bottom resulting from the abrasfve and plucking action of the glacier i t once contained. I (Ref. #2)

1 (Ref. # 2 )

"U" SHAPED VALLEY: A Val ley having a dis t inct ive ounded prof i t e and a gentle

VALLEY GLACIER: A glacier occupying a valley. Mountain glacier ; Alpine glacier. I (Ref. #1)

VALLEY TRAIN: 1.) The depos i t o f rock material carried down,by a stream originating from the me1 t i n g ice of a glacier , and thus formed i n a similar way to

wide area, b u t is confined w i t h i n the walls of a valley. 2 ) A long, ' narrow body of outwash confi,ned w i t h i n and p a r t l y f i 11 i ng a val 1 ey consisting.mainly o f s t r a t i f j e d sand and gravel carried and deposited by me1 twater , s treams .

4 an outwash,plain. Unlike the l a t te r , however, i t i s not spread over a

VERTICAL ACCRETION: .Deposits b u i l t up ver t ical ly where a stream i s subject to overbank flow and sediment i n suspension s e t t l e s on the floodplain and conforms to that surface. Compare Lateral Accretion. (Ref. #2)

VOLCANIC CONE: A cone-shaped eminence formed by volcanic discharges. (Ref. #1)

YAZOO RIVER: A tributary stream that flows for some distance parallel to the main channel because natural levees prevent i t from entering the main stream.

(Ref. #2)

24

GLOSSARY REFERENC,ES

1. American Geological In s t i t u t e , 1962; Dict<onary of GeoZogicaZ Terms, Doubleday & Co. Inc., Golden City, New York.

2. Mol lard , J . D.,, 1973 , A i r p h o t o Interpretation Manual, Commercial Printers Ltd. , Regina, Sask.

w Toronto. r 3. Selby, M. J . , 1967, The Surface of the Earth, 02. I , Cassell & Co. Ltd. ,

i

5. Wan Riper , J. E. , 1962', Man's PhysicaZ WorZd, McGraw, - Hi 11 Book Co. Inc . , Toronto.

PHOTOGRAPHS RELATED TO LANDFORMS AND VARIOUS LAND USES

Photo No. Features Mao Ref.

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7

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.OF AND · 2002-04-08 · shal low to mdderate 1 V-shaped 'I sharp angles at head f -c ends. angle...

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Transcript of .OF AND · 2002-04-08 · shal low to mdderate 1 V-shaped 'I sharp angles at head f -c ends. angle...