1. Chapter 23 Tectonics and Landforms

3. Climate

5. Differential Erosion

6. Evolution of Shields
Early Stage – maximum relief, thrust faults, folds dominate, Andes Mountains
Erosion, isostatic rebound, folds exposed at surface, Appalachian Mountains
Continued erosion and isostatic adjustment, deep folded rocks exposed at surface, Scotland, Norway
Isostatic equilibrium is established, Canadian Shield

8. Rates of Erosion of Mtn. Belt

10. Differential Erosion of Flat Strata

11. Stable Platform of N. America
Consist of 3 parts
Area underlain by Paleozoic strata in east
Great Plains region underlain by Mesozoic and Cenozoic strata in the west
Atlantic and Gulf coastal plains

12. Evolution of Columns by Differential Erosion
1. Intersecting joints separate rocks into columns.
2. Weathering and erosion along joints accentuate columns.
As weathering and erosion proceed, the cliff retreats. Old columns completely destroyed. New columns being created.

17. The Atlantic and Gulf Costal Plains
Consist of Tertiary and Cretaceous rocks
Inclined toward the sea

19. Appalachian Ridge and Valley Province
Anticlines form ridges
Synclines form valleys
Erosion soon attacks the crests
Later stages – tops of folds are eroded away. Hogback ridges are left forming a zigzag pattern.

21. Erosion of Fault Block Mountains
The original dissected upland before faulting consists mostly of valley slopes
Faulting is accompanied by accelerated stream erosion
Recurrent movement along the fault produce fresh scarps and are dissected by stream erosion.

24. Basin and Range Province
Faulting produces maximum relief, playa lakes may develop.
Mountain range is completely dissected. Alluvial fans spread out into the valley.
Basins become filled with sediment. Erosion wears down the mountain ranges to small remnants. Alluvial fans merge to form Bajadas.

26. Landscape from Basaltic Volcanism
Lava extruded, blocks drainage.
Cinder cones are worn down. Volcanic necks left. Lava flows form sinuous ridges or inverted valleys.
Inverted valleys are eroded to mesas and buttes. Volcanic necks and dikes commonly form peaks and isolated ridges.