WebJun 17, 2003 · Extrusive Igneous Rocks Extrusive igneous rocks, or volcanics, form when magma makes its way to Earth's surface. The molten rock erupts or flows above the surface as lava, and then cools forming rock. The lava comes from the upper mantle layer, between 50 km and 150 km below the Earth's surface. WebFeb 24, 2012 · Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks ( Figure below ). Extrusive igneous rocks form after lava cools above the surface. [Figure3] Extrusive igneous rocks cool much more rapidly than intrusive rocks.

Volcanic and Extrusive Igneous Rocks - ThoughtCo

WebMar 7, 2024 · Extrusive rocks erupt from volcanoes or seafloor fissures, or they freeze at shallow depths. This means that they cool relatively quickly and under low pressures. Therefore, they are typically fine-grained and … WebExtrusive rocks are formed by the molten lava which comes out of volcanoes, reaches the earth’s surface and cools down rapidly to become a solid piece of rock. For example, … dale earnhardt daytona 500 win

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Webintrusive rock, also called plutonic rock, igneous rock formed from magma forced into older rocks at depths within the Earth’s crust, which then slowly solidifies below the Earth’s surface, though it may later be exposed by … WebExtrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently … WebObsidian. Rondi: Everyone, meet Obsidian , an igneous rock that from melted rock, or magma. Obsidian is an "extrusive” rock, which means it is made from magma that erupted out of a volcano. If it was an igneous rock that formed from magma underground and did not erupt, it would have been called an "intrusive" rock. biovarnish wood stain