Unit 4: Surface Processes

1
Unit 4 Surface Processes

• Topics
• 1. Review of the Erosional-Depositional System
• 2. Landscape formations by streams
• 3. Other erosional processes

2
Review of stream erosion/deposition

• What is a bend in the stream called?
• Meander
• On which part of the meander does erosion take
  place? Deposition
• Erosion outside meander
• Depositioninside
• What are the factors that determines the amount
  of stream erosion?

3
Slope, Velocity, amount of water, soil type and
vegetation

• Discharge the total volume of the stream, amt.
  Of water and the velocity of the stream
• Slope- increase slope more velocity more
  erosion
• More water more erosion
• Soil type- smaller particles faster erosion
• vegetation more plants more roots to hold down
  soil less erosion

4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
Types of depostion

• Sorting versus unsorted and horizontal versus
  vertical (graded)
• Sorting depositing the sediments according to
  size, shape or density
• Horizontal the deposition as a stream/river
  enters a lake
• Vertical (graded) stacked vertical from quiet
  waters

8
Types of sorting

• Size the larger sediments will fall first and
  the smallest will fall last
• Shape The rounder sediments will fall faster
  (less surface area) and the flatter sediments
  will fall last (more surface area)
• Density the more dense objects will fall faster

9
Horizontal Sorting
STREAM
LAKE
Fine grained silt / clay
Large rocks medium sediments
10
Graded Bedding
11
Landscapes

• Mountains formed by tectonic activity the
  strata will be bent
• Plateaus formed by erosion agents (wind, water,
  glaciers) and the strata is still horizontal
• Plains flat lands
• What type of region do we live in?

12
Stream Patterns Landscapes

• Dendritic occurs in flat areas (plains), and
  branches off into many directions
• Trellis occurs in plateaus and areas with
  rolling hills
• Radial occurs in mountainous regions that allow
  the water to flow down the hill in all directions

13
(No Transcript)
14
Other forms of Erosion

• Wind- transports small particles and will sort
  out the sediments in deposition
• Ocean waves- removes beach sediments
• Gravity- landslides/mudflows
• Human activity- construction
• Glaciers- transports large amounts of soil and
  rock at one time (unsorted deposits)

15
Glacial Activity

• Glaciers cause a lot of erosion at one time,
  carrying tons of soil and dropping tons at the
  same time
• Therefore glaciers form many features on the
  landscape
• Many of these features can be seen in New York,
  because we were shaped by glaciers as well

16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
Glacial Features

• Glacial Till the unsorted sediment deposited by
  a glacier
• typical the rock is also scratched and polished
  with parallel grooves
• Glacial Outwash- fine grain sediment that comes
  from the top of a glacier when it begins to melt
  from the sun

24
Features cont.

• Striations parallel grooves left in the rock
  after the glacier moves over the top of it
• Moraines and Drumlins- glacial deposits that
  build up enough to make a small hill
• Cirques- bowl shape features left on the face of
  a cliff
• U-SHAPED VALLEYS!!!!

25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)