Endogenic influences on geomorphic landscapes

• 1. Endogenic Influences onGeomorphic Landscapes November 30th, 2010 Jennifer Palmer090639 Geomorphology

2. Endogenic Processes Endogenic processes: forces that causemovements beneath the Earth`s surface. Endogenic processes can consist of anythingfrom plate tectonics, earth quakes, and volcanicactivities. Endogenic processes occurs so slowly that it isvery rare to find an unmodified landform 3. Plate Tectonics Convergent boundary- coming together Divergent boundary- pulling apart Transform boundary- two plates that slidehorizontally against each other There are 7 plates that cover the earths surfaceand some smaller ones that fit in between thelarger ones 4. Convergent Boundary 5. Divergent Boundary 6. Transform Boundary 7. Tectonic Types There are two types of tectonic styles: Orogenic Processes Epeirogenic Processes 8. Orogenic Processes Mountain building processes that occur from compressional forces that are generated by continued subduction or the trapping and deformation of sediment and crust between two colliding plates 9. Epeirogenic Processes Processes that cause uplift or depression on a regional scale and proceed without internal disruption of original rock surfaces. It occurs in response to driving forces. 10. Types of Landforms Created Tectonic scarp Horsts Fault scarp Grabens Thrust-fault scarps Terraces Monoclinal scarps Rift valleys Sag ponds Topographic domes Pressure ridges Fault-block mountain Strike-slip faults Shutter Ridges Detachment faults 11. Tectonic Scarp Any steep slope that results from differential movement of the earths crust 12. Fault Scarp Occurs when a fault displaces the surface of the ground so that one side is higher or lower than the other 13. Thrust-fault Scarps Is a major process of upper crustal shorteningduring orogeny Thrusts upward through sedimentary cover strataand emerge at the land surface 14. Monoclinal Scarp Tectonic scarps with height, steepness, andlateral continuity comparable to fault scarps Formed by steep monoclines 15. Sag Ponds Found at the foot ofrecent fault scarps May develop byoblique movement orground setting 16. Pressure Ridges If the pressure on a scarp is compressional They are low elongated mounds that may parallel the surface scarp 17. Strike-Slip Fault A fault of any scale along which movement is parallel to the strike of the fault 18. Detachment Faults Very large sub horizontal faults at midcrustaldepth where the brittle upper mantle has beenextended to highly extended domains Detachment faults also contain stable areaswhich do not extend nearly as much 19. Horsts A fault block that has been uplifted relative to theblocks on either side 20. Grabens Depressions produced by subsidence along faults 21. Terraces Created by tilting, folding, uplift and faulting 22. Rift Valleys Associated with plateaus produced by broad epeirogenic up doming, crustal and lithospheric thinning, profuse volcanism, and high heat flow 23. Topographic Domes Are active anticlines or blind thrust faults in rockor sediment 24. Fault-block Mountains Occur in mostly arid regions where vegetation is sparse and geological structures are boldly exposed 25. Shutter Ridges If a fault crosses gullies or ridges all the spurends or ridge crests will be displaced in the samedirection and will become half-displaced ridgesknown as shutter ridges 26. Volcanism Most volcanic processes are associated withorogenic processes Three main instances where they occur 1. In curved volcanic arcs that probably correspondto early-stage subductive zones 2. In straight volcanic chains within post-tectonicfolded mountains 3. In lines of largely extinct volcanoes that formedwhen lithospheric plates moved over persistentmantle plumes (hot spots) 27. Hot Spots Hot areas under plates Hot spots produce long chains of volcanicislands as the plate travels over them Most hot spots are under plateinteriors, especially oceanic plates, some areclose to divergent plate boundaries and some arenear mid-oceanic ridges