What’s hiding inside? Why Wyoming’s Devils Tower is still a geological mystery Standing tall at 1,267 feet in Northeastern ...

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 ...

POTASSIUM–ARGON age determinations have been carried out mainly on minerals with a high potassium content, particularly micas and potassium feldspars, found in intermediate to acid igneous rocks, but ...

Introduction -- Physical properties of magma -- Intrusion of magma -- Forms of igneous bodies -- Cooling of igneous bodies and other diffusion processes -- Classification of igneous rocks -- ...

The Devil’s Tower, a stunning geological formation rising from the plains of northeastern Wyoming, is one of America’s most spectacular geological features. This natural monument is not only a wonder ...

There are three types of rock found on Earth. These are igneous, metamorphic and sedimentary. Each rock type is formed in a different way. For example, the rock malachite is mostly made of the ...

The Journal of Geology, Vol. 40, No. 2 (Feb. - Mar., 1932), pp. 119-139 (21 pages) A restudy, with more ample descriptions than previously published. New interpretations are that the fragmental ...

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 ...

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 ...