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....Folding the crust forms mountains?
          (...See?   It's official - crumpling the crust forms mountains....)

"Colliding continents are similar to colliding cars. If two cars run into each other, they crumple where they meet. The same thing happens with continents; the crumples are called mountains..."

"..What keeps building mountains is not obvious ?...> but most mountains are pushed upward, their rock beds wrinkled like bedsheets or tilted like stacks of newspapers.  The plates bump each other's edges in a slow-motion Demolition Derby, and that's where mountain ranges get their start. ?.....>   "Mountain belts are typically formed by plate tectonic activity, specifically continental collision."   (From - Andrew Alden, 'Arm-wavers of the centuries - landforms and features', http://geology.about.com/od/structureslandforms/a/mountainproblem.htm 
(...Andrew could (and should) do better.) (2/10)


Understanding plate motions [This Dynamic Earth, USGS]
"..The Himalayan mountain range dramatically demonstrates one of the most visible and spectacular consequences of plate tectonics. When two continents meet head-on, neither is subducted because the continental rocks are relatively light and, like two colliding icebergs, resist downward motion. Instead, the crust tends to buckle and be pushed upward or sideways. The collision of India into Asia 50 million years ago caused the Eurasian Plate to crumple up and override the Indian Plate."

"..Sometimes, when there is a convergent boundary between two continental plates, subduction cannot occur. Since continental crust is more bouyant, or less dense, than oceanic crust, one plate does not easily override the other. Instead, the plates crumple as they plow into one another, and a very high mountain range is created. This is a special type of convergent boundary called a collisional boundary. The Himalayas in India are the result of two continental plates (the Indo-Australian and Eurasian plates) colliding head on."

"Where plates serving landmasses collide, the crust crumples and buckles into mountain ranges. India and Asia crashed about 55 million years ago, slowly giving rise to the Himalaya, the highest mountain system on Earth. As the mash-up continues, the mountains get higher. Mount Everest, the highest point on Earth, may be a tiny bit taller tomorrow than it is today."

"...When two land masses meet, on the other hand, neither will slide under the other. Instead, the two crush together at what is known as a collisional boundary. They crumple and fold. Some pieces of land are thrust over or under other pieces. The result is a mountain range."

"When an ocean closes and one continent meets another continent along a convergent margin, they collide and crumple up, forming huge mountain ranges like the Himalayas; this is called a collision zone (Fig. 4.14D)."

"...Fold mountains are formed when two plates move together (a compressional plate margin). This can be where two continental plates move towards each other or a continental and an oceanic plate. The movement of the two plates forces sedimentary rocks upwards into a series of folds. Fold mountains are usually formed from sedimentary rocks and are usually found along the edges continents. This is because the thickest deposits of sedimentary rock generally accumulate along the edges of continents. When plates and the continents riding on them collide, the accumulated layers of rock crumple and fold like a tablecloth that is pushed across a table. "

"...Fold mountains are formed from the collision of continental tectonic plates. Since neither plate subducts under the other, the colliding plates wrinkle and fold like a rug being pushed into a wall."

"...While new ocean crust is constantly being created at mid-ocean ridges, old crust must either be destroyed or reduced simultaneously. Otherwise the planet would be continually expanding and increasing in volume. The plates, therefore, emerging along mid-ocean ridges, sliding over the athenosphere, and grinding past other plates along transform faults, are almost all headed on a collision course. When two continents carried on opposing plates ram into each other, they crumple and fold under the enormous pressure, creating great mountain ranges."

"..Fold moutains are actually formed by crust which have been uplifted and folded by compressional forces. This occurs along convergent plate boundaries where 2 plates move towards each other, between continental plates or between an oceanic and a continental plate. The crust and the rocks get bent and crumpled, and massive layers of Earth's crust gets uplifted as a result, forming spectacular fold mountains.

"...Where two continental plates collide, the effect is for the plates to crumple and compress, creating extensive mountain ranges, such as is occurring at the Indian and Eurasian plate-boundary with the Himalaya."

"...So when two continents come together (or collide) they tend to crumple up, generating mountains. Arabia is currently converging with Eurasia, generating mountain ranges (e.g. the Zagros of southern Iran)."

"..The mountain belts are typically formed due to plate tectonic activity. When the plates collide they crumple and stick together or are sutured together. The process that produces the mountain building is called orogenesis, which include; Folding (anticlines ? synclines), thrust faulting, metamorphism, and igneous activity. The Appalachian, Andes, Apls, Ural, Himalya, Rocky, and Cascade Mountains are great examples of the mountain belt formation."

"...If the plates collide and neither plate can subduct under the other, the crust material will just "crumple," pushing up mountains. This process does not produce volcanoes. This kind of boundary can develop later into a subduction zone."

"...When two continents carried on converging plates ram into each other, they crumple and fold under the enormous pressure, creating great mountain ranges. The highest mountain range in the world, the snow-capped Himalayas, is an example of a continent-to-continent collision. This immense mountain range began to form when two large landmasses, India and Eurasia, driven by tectonic plate movement, collided. Because both landmasses have about the same rock density, one plate could not be subducted under the other. The pressure of the colliding plates could only be relieved by thrusting skyward. The folding, bending, and twisting of the the collision zone formed the jagged Himalayan peaks. This string of towering peaks is still being thrust up as India, embedded in the Indo-Australian Plate, continues to crunch relentlessly into Tibet, on the southern edge of the Eurasian Plate."

"...In the period 1908-12, theories of continental drift were proposed by the German geologist and meteorologist Alfred Lothar Wegener and others, who recognized that continental plates rupture, drift apart, and eventually collide with each other. Such collisions crumple geosynclinal sediments, thus creating future mountain belts."

"..Fold Mountain:  Again, the name tells a lot. As one would take an article of clothing and fold it, so has the earth taken pieces of itself, and through time has, with great force, pushed pieces of earth upward and folded them over onto themselves. Example of Fold Mountains includes the Appalachian Mountains."

"..Optional - One of the questions that might be asked is if the continents are now moving apart, could they also have moved together. The answer is yes. This phenomenon is called continental collision. Colliding continents are similar to colliding cars. If two cars run into each other, they crumple where they meet. The same thing happens with continents; the crumples are called mountains. If your students are advanced enough, when you are locating and naming the continents, have them mark in the Alps, Himalayan Mountains and the Ural Mountains, or use figure 3 as your base map."

There isn't much can be added to this mythological inanity beyond observing the tremendous memic appeal enjoyed by kindergarten 'rumplecrust tectonics' when it comes to so-called 'building' of mountains, and to argue its manifest error when it comes to the global-scale reality of the Earth.  Mountains are erosional, and develop from the plateau surface that predates them (to*platstrat)and which to some degree is usually still in evidence.  They are not upthrust by any folding.  Those folds predate the erosion surface, and form (usually) fairly deep in the Earth's crust by subsidence.  Mountains develop from erosion of plateaus, not from the folding that may be exposed in/ on them.  Given the views from space (which incidentally postdate the urban myth, but were already known by travellers more than a hundred years ago) what could be more obvious?  Mountain 'building' is a destructive process, not a constructive one.

Even in Plate Tectonics, the principle driving forces are regarded as vertical - up at spreading ridges, down at subduction zones - with both of them associated with the biggest 'up-structure'  on the planet - namely the mantle breaking through the continental crust.  Why transmute this vertical driving force of an extruding mantle bubble into a horizontal force, when it already (as vertical) has the capacity to form what we see - gravitational collapse?  The true growth of ocean floors towards the ridge is clear from the structural relations at the ridges, meaning that the mantle adjacent to the continental margins is inactive, fossilized, defunct.  Transform faults tell us the spreading ridges and subduction zones were once juxtaposed.  The oceanic crust is not going down the subduction zone.  It is the continental lithosphere that is overriding the oceanic crust (/lithosphere).  As in fact Plate Tectonics advertises. Plate Tectonics readily uses this terminology and the process-dynamic overriding to describe the tectonics of continental margins, but deliberately maintains the myth of the mantle being driven under the continents, and disingenuously represents the two as the same, which they are not.

It is the effect of gravitational correction of the continental lithosphere to the enlarging surface of the Earth we are seeing, the adjustment of the early Pangaean Earth curvature to a lessening curvature, and the sliding of the lithosphere out over the mantle, that is the cause of the Fiery Ring of the Pacific, ..not any 'subduction' shoved from half a world away.  It is all happening, ..right there, .. in place, .. by gravity, ..gravitational correction of the continental lithosphere on an expanding Earth.

Folding reflects crustal collapse,  often in the highest metamorphic regimes of the crust, i.e., deep down, and SINKING .. not high up, tossed on mountains tops, and rising.  Once stratigraphic sequence emerges from the sea floor it gets rubbed down - Flat.  It's done all its folding before it even gets dry, much less uplifted to the highest reaches of the planet.

Mountains don't get 'built' deep down in the crust.  They get formed by erosion once the water recedes, and the higher they get, the more erosion makes them pointy and steep (like mountains).

The really big question here is why such a nonsensical myth as "fold mountains" gets perpetuated.

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