Previous estimates of the internal-to-extrusive ratios (internally emplaced magma versus extrusive lava flow) were based on observations over a very short time frame, in the geologic sense.

Alternatively, the cooling can extrusive, where the magma is cooled very quickly such as during a volcanic eruption. More information on igneous rocks. Igneous rocks are the "new kids" in the rock ...

The metarhyolite and metabasalt described in the column are known as extrusive rocks, those formed on the surface of the Earth. Now let’s talk about those rocks that formed from magma deep ...

Lunar igneous activities including intrusive and extrusive magmatism, and their products contain significant information about the lunar interior and its thermal state. Their distribution is ...