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 ...

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 ...

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 ...

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 ...

In the +130-year history of exploration and mining at Thor, there have been no documented occurrences of intrusive rocks. The presence of deep, underlying intrusive rocks at Thor became a high-level ...

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 ...

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 ...

I’ve been thinking about granite a lot recently; primarily because we have been covering plate tectonics in my AP Environmental Science class. Granite figures prominently in this discussion because ...

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 ...

I’ve been thinking about granite a lot recently; primarily because we have been covering plate tectonics in my AP Environmental Science class. Granite figures prominently in this discussion because ...