GEOLOGY

Detailed explanation-1: -Liquid magma is less dense than the solid material around it. Therefore, magma flows upward into any cracks in the rock above. As magma rises, it sometimes become trapped beneath layers of rock. But if an opening in weak rock allows the magma to reach the surface, a volcano forms.

Detailed explanation-2: -Magma is less dense than the surrounding rock which causes it to rise. When magma reaches the surface it is then called lava and the eruptions of lava and ash produce volcanoes. The lava that reaches the Earth’s surface will harden and become igneous rock.

Detailed explanation-3: -Decompression melting often occurs at divergent boundaries, where tectonic plates separate. The rifting movement causes the buoyant magma below to rise and fill the space of lower pressure. The rock then cools into new crust.

Detailed explanation-4: -The liquid phase of most materials is less dense than the solid phase. Thus, molten rock (magam) is less dense than solid rock.

Detailed explanation-5: -Much of the planet’s mantle consists of magma. This magma can push through holes or cracks in the crust, causing a volcanic eruption. When magma flows or erupts onto Earth’s surface, it is called lava.