Pallasite - Wikipedia
The pallasites are a class of stony–iron meteorite. They are relatively rare, and can be distinguished by the presence of large olivine crystal inclusions in the ferro-nickel matrix.
Olivine - Meteorites, Mantle, Minerals | Britannica
2024年10月4日 · Olivine - Meteorites, Mantle, Minerals: In meteorites, the olivine is usually a forsteritic variety containing only Fa15 to Fa30. In the Nakhla (Egypt) meteorite (an achondrite meteorite), the olivine is more ferrous, however, containing as much as Fa65.
Formation of Stony-Iron Meteorites in Early Giant Impacts
2010年6月10日 · Pallasites, meteorites composed mainly of olivine (Mg-Fe 2 SiO 4) and metallic Fe-Ni, are widely thought to have formed at the boundary between the metallic core of a melted and differentiated asteroid and the surrounding olivine …
Olivine: A rock-forming mineral. Used as the gemstone peridot.
Olivine is the name of a group of rock-forming minerals that are typically found in mafic and ultramafic igneous rocks such as basalt, gabbro, dunite, diabase, and peridotite. They are usually green in color and have compositions that typically range between Mg 2 SiO 4 and Fe 2 SiO 4.
Olivine-rich achondrites from Vesta and the missing mantle …
2021年9月14日 · Here we report the discovery of new olivine-rich meteorites that have asteroidal origins and are related to V-type asteroids or vestoids.
Geochemistry of pallasite olivine and the origin of pallasites
2024年10月15日 · There are three types of pallasite meteorite that are distinguished by the compositions of the metal phase, olivine Fo, their modal mineralogy, and the oxygen isotope compositions of their silicates.
Shock veins and brown olivine in Martian meteorites: Implications …
2018年6月4日 · In meteorites with brown olivine (group A), olivine is heterogeneously colored in submillimeter scale regardless of whether lherzolitic or olivine-phyric rock types. Brown areas are commonly accompanied by thin (~10 μm wide) shock veins and are brighter in BSE images compared to colorless areas.
Asteroid & Planet Mantles Yield Stony-Iron Meteorites | AMNH
Perhaps chunks of an olivine mantle fell into an outer core, where churning molten metal tore them apart. Or perhaps the iron and olivine never completely separated. No one really knows. But whatever caused the mixing, the stony-iron meteorites known as pallasites provide a snapshot of this dynamic process at the moment when the mixture solidified.
Olivine | Mineral, Rock & Magma | Britannica
2024年10月4日 · Magnesium-rich olivines are abundant in low-silica mafic and ultramafic igneous rocks and are believed to be the most abundant constituent of the Earth’s upper mantle. Olivine also occurs in high-temperature metamorphic rocks, lunar basalts, and some meteorites.
New Olivine-Rich Achondrite Meteorites Yield Insights Into the …
2021年9月21日 · These data show that the mantles of terrestrial planets are predominantly composed of the magnesium- and iron-rich mineral olivine and its high-pressure polymorphs. One of the largest asteroids, 4 Vesta, is also thought to have been differentiated and hypothesized to have an olivine-rich mantle.