Naked Science Forum
Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: The Scientist on 05/07/2010 15:11:13
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Let us know your views on the topic. Thanks.
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I know that mountains are created by crustal movements, where the plates slide past each other, pull apart from each other and plates push towards each other. But does anyone know how mountains came about besides this? Thanks and cheers!
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I know that mountains are created by crustal movements ... how mountains came about besides this?
Volcanism
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Volcanism
So does it mean that lava that are hardened formed new volcanoes?
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Volcanism
So does it mean that lava that are hardened formed new volcanoes?
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"Hawaii has lush tropical vegetation, beautiful beaches and volcanic mountains. The Kilauea Volcano is one of the most famous volcanoes in the world."
Imagine snow in the tropics?
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Here might be some idea that coincides with that volcanoes and mountains...
http://en.wikipedia.org/wiki/Category%3AMountains_of_Hawaii
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Well, another thing is do mountains have to be volcanoes or volcanoes be mountains? Thanks!
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No and no.
Many mountains are not volcanoes- Himalayas, Alps, most of the Rocky Mountains, etc. And not all volcanoes are mountains. Calderas are volcanic collapse features- actually holes in the ground. Probably the largest eruption in the past 100,000 years was Toba, which is now a lake on the island of Sumatra.
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So, in that case, how are mountains and volcanoes related?
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There are different types of volcanoes. Shield volcanoes and composite volcanoes (sometimes called stratovolcanoes) build up into mountains as the lava erupts and hardens. New lava erupts and hardens on the top of the old lava.
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Orogeny is a complex topic with a wide variety of processes involved in each situation. For example, the Alps were created by what is referred to as an overthrust due to plate tectonics, with the European plate being buried underneath oceanic crust which is in turn buried beneath African continental crust. The Rockies on the other hand were built by a sequence island arcs slamming into already established cratons. The Himalayas were built and are still being built by India slamming into Asia by means of a convergent plate boundary. There are many more causes involved in mountain building including magmatism.
You can't ask a blanket general question like that and expect a simple answer. You have to be more specific in your questions. [:)]
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Orogeny is a complex topic with a wide variety of processes involved in each situation. For example, the Alps were created by what is referred to as an overthrust due to plate tectonics, with the European plate being buried underneath oceanic crust which is in turn buried beneath African continental crust. The Rockies on the other hand were built by a sequence island arcs slamming into already established cratons. The Himalayas were built and are still being built by India slamming into Asia by means of a convergent plate boundary. There are many more causes involved in mountain building including magmatism.
You can't ask a blanket general question like that and expect a simple answer. You have to be more specific in your questions. [:)]
Welcome to the forum CreativeEnergy. Always good to have another rocker about.
I agree with your post except for your explanation of the Rockies. Rocky Mountains are formed by a combination of low angle thrusting, uplift and igneous activity, but not a series of island arc collisions. Much of California, and large parts of Oregon, Washington and British Columbia were added to North America by island arc acretion.
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Orogeny is a complex topic with a wide variety of processes involved in each situation. For example, the Alps were created by what is referred to as an overthrust due to plate tectonics, with the European plate being buried underneath oceanic crust which is in turn buried beneath African continental crust. The Rockies on the other hand were built by a sequence island arcs slamming into already established cratons. The Himalayas were built and are still being built by India slamming into Asia by means of a convergent plate boundary. There are many more causes involved in mountain building including magmatism.
You can't ask a blanket general question like that and expect a simple answer. You have to be more specific in your questions. [:)]
Welcome to the forum CreativeEnergy. Always good to have another rocker about.
I agree with your post except for your explanation of the Rockies. Rocky Mountains are formed by a combination of low angle thrusting, uplift and igneous activity, but not a series of island arc collisions. Much of California, and large parts of Oregon, Washington and British Columbia were added to North America by island arc acretion.
You could be right about the island arc acretion not being a part of the last mountain building event in that region, namely the Laramide orogeny which started during the Late Cretaceous towards the end of the Mesozoic Era some 70 to 80 million years ago and was responsible for the uplift of the Rockies and which later also led to the formation of the Grand Canyon. I'm going to have to do a little research on that. For some reason I have it in my head that besides orogeny and volcanism, island arc acretion was also a major part of the formation of the Rockies. I'm not sure where that's coming from, but I could be wrong.
I do know this though, that during the Laramide orogeny, the angle at which the Kula and the Farallon Plates were being subducted under the west coast of the North American plate, shallowed-out and the two plates ran along the bottom of the North American Plate like a conveyor belt rather than dropping down steeply into the mantle as the Pacific Plate does today along the Cascades.
Thanks for the welcome. [:)]
Eric
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Last mountain building event- Laramide? What do you have against the Eocene? [:o]
Flatlanders!
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Last mountain building event- Laramide? What do you have against the Eocene? [:o]
Flatlanders!
I should have said the last "major" mountian building event in that region. lol ;-)
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And let's not forget about the enigma of the Colorado Plateau. Is it really an uplift due to a huge piece of what once was Devonian? and earlier crust subducted beneath another crustal plate without there being deterioration of the integrity of the lower plate? (a rather far out there scenario) or is it even oceanic crust that is not degraded?
QUESTIONS, QUESTIONS, QUESTIONS
WELCOME ERIC, Glad to have another eclectic geologist.
(Bass and the rest of them just think about rocks all the time - well, except frethac. He is obsessed with speleothems and what they represent. To him a ruck is something from the Challenger Drilling Program.)