1. What is geomorphology? Definitions geo = earth morph = form -ology = study of 1

2. What is geomorphology? Definitions Surface features Surface processes Surface materials 2

3. What is geomorphology? Definitions Study of landforms and landscapes –Types of landforms Hills, valleys, floodplains, sinkholes, moraines, etc. –Types of landscapes Karst, Fluvial, Glacial 3

4. What is geomorphology? Definitions Study of surface processes responsible for landforms / landscapes –A sub-discipline is process geomorphology –Current processes –Past processes Relict landscapes/landforms ( = paleoforms). Relic is something that has survived decay or deterioration. Example of a relict landscape? 4

5. What past processes created this relict landscape? What modern processes are modifying it? 5

6. Were the processes that created the relict landforms destructional or constructional? Are the modern processes modifying this landscape destructional or constructional? 6

7. What past processes created this relict landscape? What modern processes are modifying it? 7

8. Were the processes that created the relict landforms destructional or constructional? Are the modern processes modifying this landscape destructional or constructional? 8

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10. What is geomorphology? Scale Consider scale of earth’s surface features How does scale of features relate to age? 10

11. The Earth: the ultimate landform 11

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14. Scale of landforms varies over 15 (!) orders of magnitude. continents (10 7 km 2 ) to microscale features like ripples, glacial striations (10 -8 km 2 ). Age of landforms varies over 7-8 orders of magnitude. continents (10 9 years) to microscale features like pools and riffles (10 2 years). Larger landforms most durable (longer-lasting). Smaller landforms created/destroyed faster than larger ones. Rates of geomorphic / geologic change slow for larger areas, faster when measured over small areas. example: earthquakes compared to glaciers rate of erosion in small watershed compared to larger one 14

15. William MorrisDavis introduced idea that landforms can be explained by one --or usually a combination-- of the following: Structure: rock mass (or unconsolidated material mass). Process: constructive or destructive process(es) acting now or previously on structure. Time (stage): landforms evolve through stages from continued actions of geomorphic process(es). Summary: “some rock (or soil/sediment) mass is being altered by some process, and the alteration has proceeded to a definable extent (stage) over a definite interval.” (Bloom, 1998) 15

16. Resulting Landform 16

17. Example Structure : Limestone bedrock (Paleozoic) Process : Dissolution (Cenozoic) Time : 10,000 years 17

18. Structure? Process? Time? 18

19. Structure: limestone bedrock Process: weathering (dissolution) Time: 10 3 to 10 6 years? 19

20. Structure? Process? Time? 20

21. Structure: delta sediments Process: deposition / erosion Time: 10 3 to 10 4 years? 21

22. What is geomorphology? Study of landforms and landscapes (the “what”). Study of surface processes responsible for landforms / landscapes (the “why”). Relationship between landform scale and age. Landforms can be explained in terms of structure, process and time. 22