Basalt: Dark-colored, low-silica (less than 53 percent SiO2), low viscosity volcanic rock that is relatively fluid when molten; eruptions of basalt are generally non explosive and tend to produce relatively long thin lava flows like those common in Hawaii. ... Silicic: Term used to describe silica-rich volcanic rock or magma.
www.ux1.eiu.edu/~cfjps/1300/igterms.html
Lava is red hot when it pours or blasts out of a vent but soon changes to dark red, gray, black, ... Molten rock (magma) that pours or oozes onto the Earth's surface is called lava. The higher a lava's silica content, the more viscous it becomes. For example, low-silica basalt lava can form fast-moving (10-30 miles per hour),
vulcan.wr.usgs.gov/Glossary/LavaFlows/description_lava_... vulcan.wr.usgs.gov/Glossary/LavaFlows/description_lava_flows.html
frothy, dark-colored ejecta, less siliceous, basic and more dense than ... magma-bombs and frothy pumice. The final phases are characterized by gas ... These lavas are of basic (basaltic) composition, relatively low in silicon dioxide, ... distance and at greater speeds, to form thin layers, than the rhyolitic or ...
www.nps.gov/lavo/forteachers/upload/basic_volcanic_term... www.nps.gov/lavo/forteachers/upload/basic_volcanic_terms.pdf
The continental areas are made up of close to 60 % silica, ... Mafic: “Ma” from magnesium and “fic” for iron; generally dark colored. A rock with ... “Sills” are tabular intrusions parallel or very low angle to the layering of the rocks they intrude. Dikes and sills are usually relatively narrow in width.
www.dmtcalaska.org/course_dev/explogeo/class04/notes04.... www.dmtcalaska.org/course_dev/explogeo/class04/notes04.html
Magma, as liquid, preferentially forms in high temperature, low pressure environments within several kilometers of the Earth's surface. ... Magma that is relatively poor in silica flows easily, so gas bubbles move up through it and escape fairly gently. Though an eruption of silica-poor magma can throw lava high into the air,
www.absoluteastronomy.com/topics/Magma www.absoluteastronomy.com/topics/Magma
Color banding: Alternating layers of felsic (light colored) and mafic (dark colored) minerals common in high grade metamorphic rocks. ... Felsic: A magma or rock relatively high in silicon and oxygen (together called "silica"), ... Mafic: A magma or rock high in iron and magnesium, and relatively low in silicon and oxygen.
jersey.uoregon.edu/~mstrick/MinRockID/MinRockGloss.html
Igneous: Solidified from a magma; also applied to ... Basalt: Dark-colored, low-silica (less than 53 percent SiO2), low viscosity volcanic rock that is relatively fluid when molten; eruptions of basalt are generally nonexplosive and tend to produce relatively long thin lava flows like those common in Hawaii.
www.wcc.hawaii.edu/facstaff/mccoy-f/refs.html
Basalt: Dark-colored, low-silica (less than 53 percent SiO2), low ... relatively long thin lava flows like those common in Hawaii. ... volcanic rock or magma, containing more than 68 percent silica with...
hrsbstaff.ednet.ns.ca/mcallip/Volcanoes/glossary_of_sel... hrsbstaff.ednet.ns.ca/mcallip/Volcanoes/glossary_of_selected_volcano_ter.htm
Basalt A dense, silica poor, iron and magnesium rich, usually dark colored igneous rock which constitutes the majority of the outer mantle of the earth's interior and forms the oceanic crust. ... Sill A sill is a relatively thin and wide (tabular, ... Zeolite A class of minerals produced by low-level metamorphism,
home.comcast.net/~bollesg/geology/glossary.html
Silica and the Sea ... In general, acidic and basic oxides react to give a slag that is usually of relatively low melting point. This reaction is used to remove silicates in ... It forms cubic crystals of density 2.13 g/cc that are transparent, with index of refraction 2.0. Polycrystalline SiO is used as an optical thin film,
mysite.du.edu/~jcalvert/phys/silicon.htm