Pumice is an example of extrusive igneous rock. The word extrusive means that the magma was forced onto the earth's surface and cooled in a matter of hours. Granite is an example of intrusive igneous ...

Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic ...

In my last column, I wrote about the locations where you can find igneous rocks that were formed from lava. The metarhyolite and metabasalt described in the column are known as extrusive rocks, those ...

During the nearly 14 months that it has spent on the red planet, Curiosity, the Mars Science Laboratory (MSL) rover, has scooped soil, drilled rocks, and analyzed samples by exposing them to laser ...

THE potential of the potassium–argon technique in the dating of young rocks can be evaluated by applying it to intrusive igneous rocks which are well dated by conventional geological methods. Because ...

Both volcanic and plutonic rocks occur associated with the Martinsburg formation in Lebanon County. The area is located about one-half mile south of Jonestown and is approximately six and one-half ...

We often talk about climate change, melting glaciers, or strange landforms. But we rarely think about something that’s always around us– rocks. They don’t make the news, but they’re everywhere. We ...

Scientists on NASA's Perseverance mission made a surprising discovery about the composition of rock in Jezero Crater, one that will help them get a better idea of when water existed on Mars, and ...

Scientists report on the analysis of a surprisingly Earth-like Martian rock, discovered by the Mars Science Laboratory rover Curiosity, that offers new insight into the history of Mars's interior and ...