Asbestos isn't manufactured from scratch. It grows naturally inside certain rocks over millions of years, and this category explains the geological processes that create it. That background matters in litigation, where the source and type of fiber can be a live question.
Most commercial asbestos comes from serpentinite, a rock formed when water alters magnesium-rich stone deep underground. That process, serpentinization, can grow chrysotile fibers in thin cross-fiber veins running through the rock. The starting material, or protolith, is usually an ultramafic rock like peridotite or dunite, and the whole story often begins in an ophiolite, a slab of ancient ocean floor pushed up onto land.
Other terms cover how heat and pressure reshape rock, including metamorphism, greenschist and amphibolite facies, and amphibolization, the process tied to more hazardous amphibole fibers. You'll also find the mountain-building events, like the Alpine and Taconic orogenies, that set these changes in motion.
Every term below links to a full plain-language definition.
Terms in this category
- Alpine OrogenyThe Alpine Orogeny is the long mountain-building event that created the Alps, Carpathians, Apennines, Pyrenee…
- Amphibolite FaciesAmphibolite facies is a category geologists use to describe rocks that formed under moderate-to-high temperat…
- AmphibolizationAmphibolization is a geological process in which pre-existing rocks or minerals are altered (usually through …
- Banded Iron FormationA Banded Iron Formation (BIF) is an ancient sedimentary rock made of alternating thin layers of iron-rich min…
- Contact MetamorphismContact metamorphism is the change in a rock's minerals caused by heat from a nearby body of molten rock (mag…
- Country RockCountry rock is the geological term for the existing, surrounding rock that hosts a mineral deposit, vein, or…
- Cross-Fiber VeinA cross-fiber vein is a type of mineral vein in which the fibers grow perpendicular to the walls of the vein,…
- DecarbonationDecarbonation is a geological process in which carbonate minerals such as calcite, dolomite, or magnesite rel…
- Dolomitic LimestoneDolomitic limestone is a sedimentary rock made primarily of calcium carbonate (calcite) mixed with a signific…
- DuniteDunite is a coarse-grained igneous rock made up almost entirely of the mineral olivine, formed deep within th…
- Great Oxygenation EventThe Great Oxygenation Event (GOE) was a profound shift in Earth's atmosphere and oceans roughly 2.4 billion y…
- Greenschist FaciesGreenschist facies is a category of metamorphic rock formed under relatively low-temperature and low-pressure…
- Hydrothermal AlterationHydrothermal alteration is the change in a rock's minerals caused by hot, mineral-laden water moving through …
- Iapetus OceanThe Iapetus Ocean was an ancient sea that existed roughly 600 to 400 million years ago between the early cont…
- IsogradeAn isograde is a line on a geological map that marks where rocks have reached the same grade, or intensity, o…
- MetamorphismMetamorphism is the process by which existing rock is changed by heat, pressure, or chemically active fluids …
- MetasomaticMetasomatic describes a geological process in which a rock's chemical composition is changed by hot, chemical…
- Nickel LateriteNickel laterite is a type of soil and weathered rock that forms when ultramafic rocks (rocks rich in iron and…
- Open-Cast MineAn open-cast mine (also called an open-pit or surface mine) is a type of mining operation where ore is extrac…
- Ophiolite SerpentiniteOphiolite serpentinite is a type of rock formed when slabs of ancient oceanic crust and upper mantle are push…
- PeridotitePeridotite is a dense, coarse-grained igneous rock formed deep within the Earth's upper mantle, composed most…
- ProtolithA protolith is the original, unaltered rock that existed before being transformed by heat, pressure, or chemi…
- Regional MetamorphismRegional metamorphism is a geological process in which large volumes of rock deep within the Earth's crust ar…
- RodingiteRodingite is a calcium-rich rock, often containing garnet, diopside and similar minerals, that forms when flu…
- SerpentiniteSerpentinite is a metamorphic rock made up mostly of serpentine-group minerals (such as chrysotile, antigorit…
- SerpentinizationSerpentinization is a geological process in which water reacts with iron- and magnesium-rich rocks deep in th…
- SkarnA skarn is a rock made of calcium-rich silicate minerals, such as garnet, diopside, wollastonite and tremolit…
- Supergene AlterationSupergene alteration is the chemical and mineralogical change that happens to rocks and minerals near the Ear…
- Taconic OrogenyThe Taconic Orogeny was a mountain-building event that occurred roughly 450 to 440 million years ago along wh…
- Ultramafic ProtolithAn ultramafic protolith is the original iron- and magnesium-rich parent rock (such as peridotite or dunite) t…
- Ural OrogenyThe Ural Orogeny is the prolonged mountain-building event, occurring roughly 320 to 240 million years ago, th…
- Zimbabwe CratonThe Zimbabwe Craton is an ancient, stable block of continental crust in southern Africa containing rocks more…
- Zoned Alkaline-Ultramafic IntrusionA zoned alkaline-ultramafic intrusion is a deep igneous rock body, roughly circular in shape, formed when alk…
Terms in this category
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