AGENTS OF OROGENESIS AND EROSION

1. HOW IS THE EARTH'S RELIEF FORMED AND MODIFIED?

Could you guess how these reliefs have been created or
why they have these forms?

2. OROGENESIS
Process of forming new relief
(mountains) when tectonic
plates come into contact
with or separate each other.
EROSION
Process in which relief is
destroyed.
There is a cycle of erosion:
1º EROSION
2º TRANSPORT
3º SEDIMENTATION
HOW IS THE EARTH'S RELIEF FORMED AND MODIFIED?

3. Agents of Relief formation
EARTHQUAKES
Movements of the
Earth's crust caused
by the clash of two
tectonic plates.
VOLCANOES
They are ruptures in
the Earth's core
through wich magma
and gases from the
inner core come to
the surfaceHow does Earthquakes occurs?
Eartquake
Volcano
volcanic relief
Volcán Islandia
ORIGEN DE LAS ISLAS CANARIAS

4. EARTHQUAKES

5. FAULTS (FALLAS)
When two tectonic plates clash
each other they created a
fracture in rock where there
has been movement and
displacement.
These displacemets can lead to
differents kinds of faults:
- NORMAL
- REVERSE
-SLIP FAULT

6. Real Faults
RIFT VALLEY - KENYASAN ANDREAS FAULT - CALIFORNIA

7. EROSION CYCLE
EROSION
TRANSPORT
SEDIMENTATION

8. ERODED RELIEF: GRAND CANYON (COLORADO - USA)

9. TRANSPORT OF SEDIMENTS

10. SEDIMENTATION

11. LANDSCAPE EVOLUTION

12. Agents of Erosion

There are four main agents of erosion:
− Water
− Wind
− Vegetation
− Human Action

13. Landforms (resulting from each agent)
Water
Rain Rivers (v-valleys), ravines, canyons, Badlands
(cárcavas)
Running water (agua de
escorrentía)
Badlands (cárcavas), watercourse (ramblas)
Deposition of sediments Plains, Deltas
Temperatures Water penetrates in the cracks of the rocks. Finally
the rock can be broken.
Chemical Reaction
The CO2 is mixed with the H2O
of the rainwater and this
creates a chemical reaction that
dissolves the limestone.
External Forms: Doline or sinkhole or cenote
(Dolina, uvala), Limestone pavement (lapiaz)
Internal Forms: Stalactite, stalagmite, columns,
Flowstone (colada), Helictites (Helictitas o
formaciones excéntricas). Caves, underground
rivers.

14. Wind
Wind Erodes Rocks,
Creates Dunes
Vegetation
The roots penetrate the
ground and can split
rocks.
Vegetation can help to
stop erosion.
Sugarloaf mountain (Pan de azúcar)

15. Vegetation Sugarloaf Mountain
(Pan de Azúcar)
Rio de Janeiro, Brazil

16. Waves, Marine Currents, tides Cliffs White Cliffs of Dover, England

17. Waves, marine currents, tides Arches Playa de las Catedrales, Lugo

18. Wind Natural Arch Jebel Kharaz, Jordan

19. Chemical erosion (Karst Relief) Stalactities and Column

20. Rain, Running Water Badlands (Cárcavas) Bárdenas Reales, Navarra

21. Water – Chemical Erosion (Karst
relief)
Flow stone (Colada)
La Cueva de la Autopista,
Comunidad Valenciana

22. Water, Temperatures
Cracked boulder (cracked rock)
Australia

23. Chemical Erosion Helictites (Helictitas o Formaciones excéntricas)
Cueva El Soplao, Cantabria

24. Wind
Dune
Erg Chebbi , Morocco

26. Chemical Erosion (Karst Relief)
Limestone Pavement (Lapiaz)
Madagascar
Lapiaz en Cantabria

27. Water, Rain Canyon, Ravine (Cañón, hoz) Grand Canyon, Arizona

28. Chemical Erosion,
Karstic Relief Sinkhole, Doline, Cenote (Dolina)
Sacred Cenote, Chichén Itzá, Mexico.

29. HUMAN ACTION RAILWAYS, ROADS, HIGHWAYS, TUNNELS

30. HUMAN ACTION RESERVOIR (EMBALSE)