Overarching controls

Question 1

What are the 4 overarching controls?

Answer 1

Geology, Glacial History, Physiography, Climate/Regime Control/Land use

Question 2

System linkage- what is the importance?

Answer 2

• Hillslope coupling will have a direct impact on channel morphology and thus, biota
• knowledge of underlying material and its interactions with water which can help us understand system disturbances

Question 3

What is the Western Cordillera geology?

Answer 3

-Landform in the west of Canada
-formed 200 mya
-ocean sediment and older rocks pushed east and
folded and faulted as they formed
-some rocks intruded by magma
-resulted in variability of mineral composition of rocks

Question 4

What is hillslope coupling?

Answer 4

the interactions between a slope and a river

Question 5

Coastal mountains

Answer 5

• interlocking igneous intrusions and metamorphic rock
• result of plate tectonics
• contains Canada highest peaks

Question 6

Interior Plateau

Answer 6

• underlain by folded and faulted sedimentary and volcanic rock layers
• Fraser River Valley

Question 7

Eastern mountains

Answer 7

• Sedimentary rocks that have been tilted, folded and faulted
• Columbia mountains and rocky mountains

Question 8

How are physiographic regions classified?

Answer 8

• erosion
• deposition
• bedrock response to erosion
• orogenic history (event that leads to both structural deformation and compositional differentiation of the Earth’s lithosphere)

Question 9

4 features of the B.C. Physiographic Region

Answer 9

1) 4 parallel mountain ranges
2) arranged by ascending order young –> old
3) Extending along N-S axis
4) Drained by several river (Fraser and Columbia)

Question 10

How did glaciation impact the surficial geology of BC?

Answer 10

-created a thick sedimentary package overlaying bedrock

Question 11

What is surficial material?

Answer 11

• deposits which lie on top of bedrock (not soil)

- deeper earth materials that lay beneath soil zone and bedrock

Question 12

When did the Wisconsin glaciation occur? What was it?

Answer 12

approx 25,000 ya

ice sheet >2km that repeatedly advanced and receded

Question 13

When did the rapid glacial melting to deglaciation occur?

What was the result of it?

Answer 13

Between 18000-11000 ya

Surficial geology of the lower Fraser lands

Question 14

What is a U shape valley?

Answer 14

deep glacial trough through mountains formed from glaciers

Question 15

What is drift?

Answer 15

any deposit of glacial origin

Question 16

what is till?

Answer 16

unsorted/unstratified material left behind by glaciers (not water)

Question 17

what is outwash?

Answer 17

sorted/stratified deposits made by glacial melt streams

Question 18

What are some Glacial Surficial features?

Answer 18

Drumlins, Ground and end moraines, kame, kame terrace, outwash plain

Question 19

What is a ground moraine?

Answer 19

blanket of till covering bedrock. Also called Lodgement till, a compact, dense, clay rich mound formed under the glacier.

Question 20

what is an end/terminal moraine?

Answer 20

long, irregularly rounded, narrow ridge of till formed at the retreating edge of a glacier. Also called an Ablation till, made up of sand and silt, unstable and loose.

Question 21

What is a Drumlin?

Answer 21

streamlined hill of till; tear dropped shaped with point in the direction of glacial retreat. more common in groups

Question 22

Kame terrace?

Answer 22

a platform of till deposited who’s surface is higher than that of the valley floor.

Question 23

outwash plain

Answer 23

• fairly flat, well drained plain
• formed by large quantities of meltwater
• commonly found infront of end morraines

Question 24

kame

Answer 24

irregular shaped hill or mound formed in a depression on retreating glacier, deposited by melt water
-sand, gravel and till

Question 25

Braided outwash plain

Answer 25

flat wide, unpredictable

• tons of sediment
• very unstable

Question 26

Supra-glacial melt out till

Answer 26

made up of angular clasts with coarse unimodal grain size. Material eroded from the upper parts of valleys.

Question 27

Sub-glacial melt out till

Answer 27

rounded, spherical clasts with bimodal distribution (silt/clay).

Question 28

Ablation till

Answer 28

• Colluvial depoited onto glacier and then deposited into glacier, melt out of ice
• usually sand and silt
• ontop of lodgement till
• much looser than lodgement till

Question 29

Lodgement till

Answer 29

deposited by a moving glacier; underneath glacier, compressed and compacted
-dense and clay rich

Question 30

Glaciofluvial sediment

Answer 30

• materials transported by glacial river/melt water
• usually sands and gravels- more coarse, high flow
• worked beyond glaciers extent
  (i. e GF outwash- well sorted, stratified and generally round clasts)

Question 31

Glaciolacustrine sediment

Answer 31

formed in a lake where material was deposited by glacier meltwater(underneath glacier)
-v. fine material (silt and clay)
-settles perfectly level in a platy structure
-very erodible
-

Question 32

till veneer vs. till blanket

Answer 32

veneer thin

blanket thick

Question 33

What system classifies terrain?

Answer 33

BC terrain classification system

Question 34

sgFGt-FI classify this terrain

Answer 34

Composed of  sg-sand and gravel
Parent material - Glaciofluvial
Landform - terrace
- means modified by
Geomorphic process - slow down slope failure that are no longer active