What is a crack?

depending on whether the context of tectonics or volcanic plate is the term "rift zone" to mean two different but related things; In general, it can be considered an area where a rock has been stretched in the Earth's crust, resulting in a crack and a fracture through which Magma can rise like lava to the surface. Lava may vary by its origin and different types of lava have different physical properties. They form zones of cracks in areas where the magma is under the surface of basalt nature - this type of lava is a relatively rhinitis and has a low gas content. This means that eruptions are not explosive: instead, the lava tends to flow out of the fractures in the bark. Basalt or Mafic lava comes from a deep cloak and is associated with spread centers or areas where continental boards move apart.

Rift Zones can form in these width centers, where the bark is stretched by a convection inside the sheath. There is a lineDa cracks of this type in the form of middle ocean ridges, such as the North Atlantic ridge, where the North American and Eurasian plates move apart. Here is the ocean bark of the slot and the ridges are formed by the solidification of the magma rising to the surface. Gradual spread from the oceanic crust in these areas limits the extent in which the combs can accumulate, but in some particularly active areas, sometimes called "hot places", the new rock that forms relatively fast

tectonic zones of cracks can also appear on the ground where new division is created and creates boards that move apart. A good example is the large Rift valley in East Africa. The Earth sinks along the division line and creates an expanding valley between two volcanic combs. The event is immersed under the sea level, ocean water flows and creates a new ocean.

Over time, repeated pouring basalt lava that occurs in hot places can create a type of large volcano known as a volcanohere. They have long, fine slopes made of many layers of hardened basalt lava, and on their slopes, located cracks can be created to stretch the rock due to gravity. Large fractures can form at the points of weakness in the rock, allowing lava to flow to the surface and lead to lateral eruptions, unlike eruptions from the main ventilation opening. As with the eruptions of the ocean floors, they are insignificant in nature. Mauna Loa in Hawaii provides an example of a textbook of this kind of rift zone.

There are a number of distinctive geological elements that are associated with zones torn on the volcanoes of shields. The playgrounds are wall -mounted structures formed by lava, which was reached into fractures in the rock and stiff. The stiff lava is often heavier than the rock that erodes faster and leaves the dam exposed. The eruptions of the cracks can throw away the balls of molten lava, known as "spray", several meters into the air. They can accumulate around eruption sites, create spray cones and multiple linear structures called rAmparts.

cracks zones are not limited to Earth. On Mars is a huge canyon known as Valles Marineris a huge zone of cracks, which long for 2,000 miles (3,000 kilometers) and up to 12,500 feet (3,800 meters) deep, dwarves on our planet. It is assumed that it has been created for a period of 3.5 billion to 2 billion years and seems to have emerged from the stress associated with the main volcanic activity in the area.