What type of plate boundary causes rifts in Earth's surface?

Question

There are three types of plates boundaries:
1) Divergent
2) Convergent
3) Transform

Answer 1

A rift is caused by #1 - Divergent boundary. This is where the plates are spreading apart and have a "tear" or opening between the plates for magma to ooze out and form new land.

A convergent boundary is where two plates come together. One is forced under the other so it melts to reform the magma. These boundaries are found around the Pacific "ring of fire".

A transform boundary is where the plate slide past each other as in one moving north and the other south. Think San Andreas fault.

Answer 2

Places where plates are coming apart are called divergent boundaries. The Mid-Atlantic is an example of a divergent boundery. Earth's brittle surface layer (the lithosphere) is pulled apart, it typically breaks along parallel faults that tilt slightly outward from each other. As the plates separate along the boundary, the block between the faults cracks and drops down into the soft, plastic interior (the asthenosphere). The sinking of the block forms a central valley called a rift. Magma (liquid rock) seeps upward to fill the cracks. In this way, new crust is formed along the boundary. Earthquakes occur along the faults, and volcanoes form where the magma reaches the surface.

Where a divergent boundary crosses the land, the rift valleys which form are typically 30 to 50 kilometers wide. Examples include the East Africa rift in Kenya and Ethiopia, and the Rio Grande rift in New Mexico. Where a divergent boundary crosses the ocean floor, the rift valley is much narrower, only a kilometer or less across, and it runs along the top of a midoceanic ridge. Oceanic ridges rise a kilometer or so above the ocean floor and form a global network tens of thousands of miles long. Examples include the Mid-Atlantic ridge and the East Pacific Rise.

Answer 3

Use google and look it up. You'll get a more detailed answer than from here. And check Wikipedia. The basic idea. Tectonic plates move against each other. That friction creates earthquakes, mountains, volcanoes, etc.