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 ...

This 1930s educational film explores the natural landscapes, geological formations, and agricultural practices of the time. It features scenes of farmers tilling soil, majestic mountain roads ...

Books Received Published: 28 September 1929 The Evolution of the Igneous Rocks A. H. Nature 124, 474–475 (1929) Cite this article ...

Books Received Published: 03 July 1926 The Petrology of the Igneous Rocks Nature 118, 8 (1926) Cite this article ...