How does the earthform?

Answer 1

The Earth's surface has not always had the same form or with the same continents as it has now. A process of plate tectonics has the continents drifting (at an incredibly slow but measurable pace) across the surface. They split apart and ram back together to form new land masses. The Himalayan mountains were formed when the Indian land mass pushed into the southern boundary of the ancient Asian land mass, folding the crust and forming mountains. Other mountains were formed by similar processes.

The Earth's crust was originally formed from igneous rocks, much like the rocks formed when lava cools. These rocks gradually weathered away into sand and silt, which were deposited in the valleys and on the ocean bed. Here, they were compressed into sedimentary rocks such as sandstone and shale. The earth's surface is constantly changing, and many sedimentary rocks were later uplifted to form new mountains.