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 ...

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 ...

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 ...

Thundereggs look like regular rocks from the outside, but contain intricate and colorful mineral patterns inside — often made ...

Sedimentary rocks are made up of pieces of older rocks (igneous, metamorphic, and sedimentary) and organic remains (shells, bone, etc.). When rocks break apart from erosion they are transported by ...

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 ...