What goes on four legs at dawn, two at noon, and three at dusk?
I. Landscapes are the physical features of the earth’s surface.
•Result from weathering, erosion, deposition and uplift.
Mountains, Plateaus and Plains
•Are the 3 major landscape classifications.
defined by three
2. Type of Bedrock
3. Stream Drainage
II. Forces resulting in Landscapes
1. Uplifting Constructive Forces
- Mountain Building & Deposition
2. Leveling Destructive Forces
- Weathering & Erosion
Landscapes are in a constant cycle of erosion, deposition, & uplift.
A dynamic equilibrium can be reached when…..
• a balance between erosion and uplift is equal.
If uplifting is greater than erosion a mountain will grow.
If erosion is greater then uplift a valley will result.
mountain ranges have
angular features and are
Old mountain Ranges have
more erosional features and
the fault line
features of the old
III. Landscapes are Separated by Boundaries
1. Two adjoining massive structures with different elevations
2. Each having different bedrock compositions
ESRT page 2 & 3
Allegany Plateau @ Helderburg Escarpment in Albany
Valley Floor Of Post Glacial Lake Albany
Allegany Plateau @ Letchworth State Park in Western
New York 300 miles away from Albany
Resistant Bedrock With Same Composition and Fossils As
the Helderburg Escarpment
IV. Effects of Climates On Landscapes
1 Climate factors such as temperature & moisture greatly effect
a) Moist climates create rounded hill slopes…
· With well-developed soils
· Permanent stream patterns
b) Arid climates produce steep angular cliff faces.
· Have poorly developed soils
· Seasonal streams
V. Bedrock composition will influences the type of Landscape
(Competent Rocks) are hard and resistant bedrock layers which
protect underlying stones from weathering and erosion.
-Due to their strong chemical composition.
(Incompetent Rocks) are weak & least resistant to weathering.
- Softer layers tend to have been cut into & have debris piles.
Due to their weak chemical compositions.
End Stage of a Plateau:
With an arid climate and resistant bedrock mesa’s are
produced in Arizona's Valley of the Gods
The meandering Goose Necks of the Green River.
• Note the arid bedrock features & poor soil development.
The Grand Canyon opens on the Colorado Plateau.
Arches National Park
Hoodoo’s and Arches carved by differential weathering of wind
abrasion and rare rainfall events in the southwestern desert
Ship Rock a volcanic plug known as a kimberlitic pipe is
the remnants of a weathered volcano
Indian Dwellings Carved
into Volcanic Tuff
VI. Drainage Patterns & Basins
A drainage basin is a geographic area in which water will collect:
1. all streams flow from high to low elevations
2. water eventually reaches the ocean
3. drainage basin are delineated by mountain divides
· A pattern of stream development formed on plateaus.
· The composition and hardness of the bedrock is consistent .
Dendritic Stream Pattern.
B. Annular (Rings):
Drainage occurs around a dome.
A Dome Showing
· Drainage occurs around a volcano.
D. Trellis Drainage
Water flows straight along the fault lines
VII. Human Activities Influence the Landscape
· Excavations for city development, road construction, field
cultivation, and deforesting practices can increase erosion .
Which can result in
-Negative economic impacts
-Reducing ground water supplies
-Increases subsurface pollution
Landscape destruction can be prevented
- Tilling and contour farming
- Natural Pesticides
- Zoning land masses for forest preserves
- Rebuilding waste water treatment facilities
- Recycling to reduce landfills and dumps.