2017-01-17T11:03:12ZLearn the basics of rocks and minerals, where to find them and what they mean in their context.
2017-01-17T11:03:12ZSteno (Niels Stensen) first set forth some of the basic principles that all geologists follow.
2017-01-17T11:03:12ZThe Appalachian Mountains contain a very complex (and lengthy) geologic history. Learn more about what makes them so special.
2017-01-17T11:03:12ZThe silica tetrahedron is the basis of the silicate minerals.
2017-01-17T11:03:12ZThe oceanic crust is much younger than the continental crust, rarely reaching more than 180 million years in age.
2017-01-17T11:03:12ZSeveral times in Earth history, plate tectonics has pushed all or most of the continents together into one big mass.
2017-01-17T11:03:12ZActinolite is a major amphibole mineral. Page 5.
2017-01-17T11:03:12ZSlate is a major metamorphic rock type from regional metamorphism. Page 17.
2017-01-17T11:03:12ZMinerals meet four criteria, more or less strict.
2017-01-17T11:03:12ZWhat a petrified thing is as opposed to a fossilized thing.
2017-01-17T11:03:12ZAugite is one of the pyroxene minerals. Page 2.
2017-01-17T11:03:12ZSubduction occurs along convergent boundaries involving at least one oceanic plate. As the tectonic plates collide, one sinks below the other.
2017-01-17T11:03:12ZGeologic map of Utah, part of a set of all 50 states. Page 44.
2017-01-17T11:03:12ZPyroxenite is one of the major igneous rock types. Page 19.
2017-01-17T11:03:12ZTuff is one of the major igneous rock types. Page 26.
2017-01-17T11:03:12ZQuartz monzonite is one of the major igneous rock types. Page 20.
2017-01-17T11:03:12ZAbout this staple of igneous petrology.
2017-01-17T11:03:12ZTroctolite is one of the gabbroid rocks: igneous, plutonic and mafic. Page 25.
2017-01-17T11:03:12ZIndex fossils come from organisms that were distinct, widespread, abundant and short lived. These fossils help define intervals of geologic time.
2017-01-17T11:03:12ZFind and see geological landforms at About.com Geology.
2017-01-17T11:03:12ZQuartz is classified as a rock-forming mineral. Page 9.
2017-01-17T11:03:12ZIn rocks, what is not there can be as informative as what is there.
2017-01-17T11:03:12ZGeologic map of Texas, part of a set of all 50 states. Page 43.