If 4.5 billion years of erosion and deposition have occured why isn't the earths surface more level?

Question

Are all rocks likely to weather at the same rate?

Answer 1

Because you forgot the 4.5 billion years of up lift and the rain of meteors on the earth.

Then you forgot the action of volcanos.

Answer 2

A couple got it right. It is indeed the movement of the plates. The plates collide. For example, the North American plate rides over the Pacific plate, where it is not sliding sideways. The plates push up mountains. The Sierras are a good example. Previously the Rockies were pushed up when the continent was smaller. As a geologist, I have studied the rocks and have learned how continents are formed. It happens over many millions of years and as you suggested billions of years. In those time scales, the continents have bounced around like a pin ball machine. The continental plates are what is preferentially melted with high concentration of silica and lighter minerals. Oceanic plates are typically much thinner and denser. The evidence for plate techtonics is really indisputable.

Answer 3

Some rocks are harder than others and will weather and erode slower than other rocks...but the real answer to your questions is that the earth's surface isn't level because of plate tectonics. The earth's crust is made up of plates that move around - when the crash into each other, they can cause uplift, raising rocks up to be erodes again.

Answer 4

the moving of techtonic plates and volcanos are always building up the surface and pushing other parts down. Also all rocks are not created equil, there are three basic kinds ignious medamorphic and sedimentary (rocks formed by the cooling of lava, Metamorphic rocks are rocks that have "morphed" into another kind of rock. These rocks were once igneous or sedimentary rocks. How do sedimentary and igneous rocks change? The rocks are under tons and tons of pressure, which fosters heat build up, and this causes them to change. If you exam metamorphic rock samples closely, you'll discover how flattened some of the grains in the rock are those formed by layers of sediment so its not all the same.

Answer 5

Because the Earth is constantly shifting. The tectonic plates push together and form mountains, while erosion causes things to flatten down.

Answer 6

Because the Tectonic plates of the earth keep moving up and down changing the surface topography

Answer 7

Not all rocks weather at the same rate. Don't forget that plate tectonics creates new mountain ranges and volcanoes create mountains and islands.

Answer 8

Because of constant tectonic activity.

Also, not all rocks weather at the same rate....for example granite will take longer to erode than limestone.

Answer 9

Not necessarily, but with the constant replacment of land and the upheaval of the land masses, if causes more changes

Answer 10

because the earth has only been arounf 6 thousand years