The group is part of the SNC martian trio and named after the meteoriteWork in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and seen to fallMeteorite seen to fall. Such meteorites are usually collected soon after falling and are not affected by terrestrial weathering (Weathering = 0). Beginning in 2014 (date needs confirmation), the NomComm adopted the use of the terms "probable fall" and "confirmed fall" to provide better insight into the meteorite's history. If in Chassigny, France, in 1815. Its subsequent recovery led to it being one of the first meteorites to be recognized as a genuine rock from space. Chassigny resembles a terrestrial dunite – a coarse-grained, deep-seated igneous rockOne of the three basic types of rock that also include sedimentary and metamorphic. Igneous rocks are formed by the solidification of magma and comprised predominately of silicate minerals. Based on bulk chemical analysis, igneous rocks can be grouped into four major groups based on their SiO2 content: 1. Felsic: – and consists of ~91% Fe-rich olivineGroup of silicate minerals, (Mg,Fe)2SiO4, with the compositional endpoints of forsterite (Mg2SiO4) and fayalite (Fe2SiO4). Olivine is commonly found in all chondrites within both the matrix and chondrules, achondrites including most primitive achondrites and some evolved achondrites, in pallasites as large yellow-green crystals (brown when terrestrialized), in the silicate portion, 5% clinopyroxene, 1.7% plagioclaseAlso referred to as the plagioclase feldspar series. Plagioclase is a common rock-forming series of feldspar minerals containing a continuous solid solution of calcium and sodium: (Na1-x,Cax)(Alx+1,Si1-x)Si2O8 where x = 0 to 1. The Ca-rich end-member is called anorthite (pure anorthite has formula: CaAl2Si2O8) and the Na-rich end-member is albite, 1.4% chromiteBrownish-black oxide of chromium and iron (Cr-Fe oxide), Cr2FeO4, found in many meteorite groups., 0.3% melt inclusions, and other minerals. Cracks within Chassigny are filled with carbonateMineral or compound containing carbon and oxygen (i.e. calcium carbonate, CaCO3, calcite). and sulfate salts that point to chemical alteration by water before its arrival on Earth. Its crystallizationPhysical or chemical process or action that results in the formation of regularly-shaped, -sized, and -patterned solid forms known as crystals. age of 1.36 Ga and composition suggest a close relationship with nakhlites and an origin from the same parent magmaMolten silicate (rock) beneath the surface of a planetary body or moon. When it reaches the surface, magma is called lava. on Mars. However, Chassigny contains noble gasElement occurring in the right-most column of the periodic table; also called "inert" gases. In these gases, the outer electron shell is completely filled, making them very unreactive. values entirely different from those found in other Martian meteorites or the Martian atmosphere. If these gases came from the Martian mantleMain silicate-rich zone within a planet between the crust and metallic core. The mantle accounts for 82% of Earth's volume and is composed of silicate minerals rich in Mg. The temperature of the mantle can be as high as 3,700 °C. Heat generated in the core causes convection currents in, as suspected, Chassigny must have originated within a plutonGeology: Igneous intrusive body that forms when magma is injected into host rocks and solidifies. Plutons occur in the crust of asteroids undergoing differentiation or planets. Named after Pluto, the Roman god of the underworld. Plutonic rocks are the rocks found within a pluton. Astronomy: Category of planet including all deep inside the Martian crustOutermost layer of a differentiated planet, asteroid or moon, usually consisting of silicate rock and extending no more than 10s of km from the surface. The term is also applied to icy bodies, in which case it is composed of ices, frozen gases, and accumulated meteoritic material. On Earth, the.
Some or all content above used with permission from J. H. Wittke.