(or CV7; Achondrite with an almost chondritic composition with age similar to the primordial chondrites. These should be better classified as "metachondrites". in MetBull 89)
Purchased March 2004
no coordinates recorded Several stones weighing together ~4.2 kg were found in the Sahara Desert and later sold to a collector in Zagora, Morocco in March 2004. This Work 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 Click on Term to Read More was analyzed at Northern Arizona University (T. Bunch and J. Wittke) and the University of Washington in Seattle (A. Irving and S. Kuehner), and it was initially determined to be a highly recrystallized (~120° triple junctions), highly equilibrated (W sequestration into Element that readily forms cations and has metallic bonds; sometimes said to be similar to a cation in a cloud of electrons. The metals are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the metalloids and nonmetals. A diagonal line drawn Click on Term to Read More) L7 Chondrite meteorites are the most common accounting for 83.6% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), free Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such Click on Term to Read More with no relict Roughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at ~1400 ° C. Large numbers of chondrules are found in all chondrites except for the CI group of carbonaceous chondrites. Chondrules are typically 0.5-2 mm in diameter and are usually composed of olivine Click on Term to Read More apparent. Notwithstanding this L7 classification, a subsequent Element that makes up 20.95 vol. % of the Earth's atmosphere at ground level, 89 wt. % of seawater and 46.6 wt. % (94 vol. %) of Earth's crust. It appears to be the third most abundant element in the universe (after H and He), but has an abundance only Click on Term to Read More One of two or more atoms with the same atomic number (Z), but different mass (A). For example, hydrogen has three isotopes: 1H, 2H (deuterium), and 3H (tritium). Different isotopes of a given element have different numbers of neutrons in the nucleus. Click on Term to Read More study was conducted at the University of Western Ontario (T. Larson) which showed that NWA 3133 plots on the Carbonaceous chondrites represent the most primitive rock samples of our solar system. This rare (less than 5% of all meteorite falls) class of meteorites are a time capsule from the earliest days in the formation of our solar system. They are divided into the following compositional groups that, other than Click on Term to Read More Anhydrous Inorganic substance that is (1) naturally occurring (but does not have a biologic or man-made origin) and formed by physical (not biological) forces with a (2) defined chemical composition of limited variation, has a (3) distinctive set of of physical properties including being a solid, and has a (4) homogeneous Click on Term to Read More (CCAM) line clearly within the field of Meteorite class named after the Vigarano meteorite that fell in Italy in 1910. They have abundant large, well-defined rimless (?) chondrules of magnesium-rich olivine (~0.7 mm diameter; 40-65 vol. %), often surrounded by iron sulfide. They also contain 7-20 vol. % CAIs. The often dark-gray matrix is dominated by Fe-rich Click on Term to Read More (see the O-isotope plot and diagram below).
click on image for a magnified view
click on diagram for a magnified view Diagram credit: Sanborn et al., 49th LPSC, #1780 (2018) Utilizing the Mn–Cr age chronometer anchored to the Type of evolved achondrite meteorite that represent some of the earliest stages of asteroidal differentiation and magmatism in our solar system. Angrites are named for the Angra dos Reis meteorite, which fell in Rio de Janeiro, Brazil, in early 1869. They are basaltic (mafic) rocks, often containing porous areas, and Click on Term to Read More NWA 4801, an absolute Physical or chemical process or action that results in the formation of regularly-shaped, -sized, and -patterned solid forms known as crystals. Click on Term to Read More age of 4.5615 (±0.0004) b.y. has been calculated (Shukolyukov et al., 2011). In a similar case, the Pb–Pb age anchored to the Type of evolved achondrite meteorite that represent some of the earliest stages of asteroidal differentiation and magmatism in our solar system. Angrites are named for the Angra dos Reis meteorite, which fell in Rio de Janeiro, Brazil, in early 1869. They are basaltic (mafic) rocks, often containing porous areas, and Click on Term to Read More NWA 4801 gives an absolute age of 4.5580 (±0.00013) b.y. NWA 3133 experienced an early thermal history beginning ~6 m.y. after Sub-millimeter to centimeter-sized amorphous objects found typically in carbonaceous chondrites and ranging in color from white to greyish white and even light pink. CAIs have occasionally been found in ordinary chondrites, such as the L3.00 chondrite, NWA 8276 (Sara Russell, 2016). CAIs are also known as refractory inclusions since they Click on Term to Read More formation. Prior to its catastrophic disruption, this planetesimal possibly comprised multiple lithological zones including a metallic core (iron), a core–mantle boundary (One of two main classes of stony-iron meteorite, the other being mesosiderites. Pallasites are igneous in nature and characterized by crystals of olivine, sometimes peridot (green gem quality clear olivine crystals), embedded in a matrix of Fe-Ni metal. The type specimen, weighing 680 kg, was found in the mountains near Click on Term to Read More), an upper mantle impact-melted zone composed of metal+The most abundant group of minerals in Earth's crust, the structure of silicates are dominated by the silica tetrahedron, SiO44-, with metal ions occurring between tetrahedra). The mesodesmic bonds of the silicon tetrahedron allow extensive polymerization and silicates are classified according to the amount of linking that occurs between the assemblages (silicated iron), a high-temperature zone (dunite), an intensely thermally metamorphosed stratigraphy (Term used to describe a metamorphosed chondrite. Also referred to as a type 7 chondrite. Metachondrites are texturally evolved rocks derived from chondritic precursors and some have been classified as primitive achondrites. Click on Term to Read More), and a primitive, insulating chondritic Mixture of unconsolidated rocky fragments, soil, dust and other fine granular particles blanketing the surface of a body lacking an atmosphere. Regolith is the product of "gardening" by repeated meteorite impacts, and thermal processes (such as repeated heating and cooling cycles). Click on Term to Read More which has experienced impact-gardening and metasomatism. See ‘The Breakup of Antaeus’ for additional details. Further evidence for a large differentiated CV planetesimal lies in the fact that Allende acquired a strong unidirectional natural remanent magnetization at least 8 m.y. after CAI formation, reflecting the existence of an internal core dynamo (Weiss et al., 2010). The photo shown above is a 1.41 g partial slice of NWA 3133, the first meteorite distinguished as a metachondrite.