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  2. Magma - Wikipedia

    en.wikipedia.org/wiki/Magma

    Petrologists routinely express the composition of a silicate magma in terms of the weight or molar mass fraction of the oxides of the major elements (other than oxygen) present in the magma. [19] Because many of the properties of a magma (such as its viscosity and temperature) are observed to correlate with silica content, silicate magmas are ...

  3. Ringwoodite - Wikipedia

    en.wikipedia.org/wiki/Ringwoodite

    Ringwoodite is polymorphous with forsterite, Mg 2 SiO 4, and has a spinel structure.Spinel group minerals crystallize in the isometric system with an octahedral habit. Olivine is most abundant in the upper mantle, above about 410 km (250 mi); the olivine polymorphs wadsleyite and ringwoodite are thought to dominate the transition zone of the mantle, a zone present from about 410 to 660 km

  4. Extrusive rock - Wikipedia

    en.wikipedia.org/wiki/Extrusive_rock

    Shield volcanoes are large, slow forming volcanoes [6] that erupt fluid basaltic magma that cools to form the extrusive rock basalt. Basalt is composed of minerals readily available in the planet's crust, including feldspars and pyroxenes. [2] Fissure volcanoes pour out low viscosity basaltic magma from fissure vents to form the extrusive rock ...

  5. Phases of ice - Wikipedia

    en.wikipedia.org/wiki/Phases_of_ice

    Crystal structure of Ice XI viewed along the c-axis Crystal structure of ice XI (c-axis in the vertical direction) Ice XI is the hydrogen-ordered form of the ordinary form of ice. The total internal energy of ice XI is about one sixth lower than ice I h, so in principle it should naturally form when ice I h is cooled to below 72 K.

  6. Mineral - Wikipedia

    en.wikipedia.org/wiki/Mineral

    Mineral. Crystals of serandite, natrolite, analcime, and aegirine from Mont Saint-Hilaire, Quebec, Canada. In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form. [1][2] The geological ...

  7. Convection - Wikipedia

    en.wikipedia.org/wiki/Convection

    Natural convection is a flow whose motion is caused by some parts of a fluid being heavier than other parts. In most cases this leads to natural circulation: the ability of a fluid in a system to circulate continuously under gravity, with transfer of heat energy. The driving force for natural convection is gravity.

  8. Geomorphology - Wikipedia

    en.wikipedia.org/wiki/Geomorphology

    Geomorphology (from Ancient Greek: γῆ, gê, 'earth'; μορφή, morphḗ, 'form'; and λόγος, lógos, 'study') [2] is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand ...

  9. Mineralogy - Wikipedia

    en.wikipedia.org/wiki/Mineralogy

    Mineralogy[n 1] is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution ...