So what exactly are the processes that take So what exactly are the processes that take place to form these mountains?place to form these mountains?
• Dome mountains– Magma pushes up but doesn't actually crack through
the surface, you can get a dome mountain – Without erupting onto the surface, magma pushes up
overlaying rock layers– Cools and forms hardened rock as source moves
away– Uplifted area created by rising magma is called a
dome– Over long periods of time, erosion wipes away the
outer layers of the mountain, exposing the dome-shaped cooled magma of harder rock
For a more
holistic view of
mountains…
So what exactly are the processes that take So what exactly are the processes that take place to form these mountains?place to form these mountains?
• Plateau mountains– Large flat areas pushed above sea level by
forces within the Earth or formed by layers of lava
– Plateau mountains are often found near folded mountains
– As years pass, streams and rivers erode valleys through the plateau
For a more
holistic view of
mountains…
So what exactly are the processes that take So what exactly are the processes that take place to form these mountains?place to form these mountains?
• Volcanic mountains– Self-explanatory!– More details in the future lessons!
Mountain BuildingMountain Building
• 3 stages(1) accumulation of sediments
(2) rock deformation and crustal uplift
(3) a period of crustal uplift caused by isostatic rebound and block-faulting
Stage 2: Rock Deformation and Stage 2: Rock Deformation and Crustal UpliftCrustal Uplift
• Fold mountains– Fold mountains are
formed when two plates collide head on
– Edges of each tectonic plate crumple and buckle
– Monocline, syncline, anticline,
http://www.physicalgeography.net/fundamentals/10k.html
Stage 3: Crustal Uplift caused by Stage 3: Crustal Uplift caused by Isostatic Rebound and Block-Faulting Isostatic Rebound and Block-Faulting
http://www.physicalgeography.net/fundamentals/10k.html
Stage 3: Crustal Uplift caused by Stage 3: Crustal Uplift caused by Isostatic Rebound and Block-Faulting Isostatic Rebound and Block-Faulting
• Fault-block mountains– Faults named according to type of stress that acting
on rock and nature of the movement of the rock blocks either side of the fault plane
• Normal (tensional)• Reverse (compressional)• Graben (tensional, subsidence)• Horst (compressional, uplift)• Transform
• What landform does faulting remind you of?