Rare type of primitive achondrite named after the Lodran meteorite that fell in Pakistan in 1868. Initially, lodranites were grouped with the stony-iron meteorites because they contain silicates (olivine, orthopyroxene, and minor plagioclase) and Fe-Ni metal in nearly equal proportions. However, since discovery of the closely related acapulcoite group, lodranites Click on Term to Read More
(previously classified as Iron, IAB complex, NWA 468 duo)
Purchased before January, 2000
no coordinates recorded A relatively fresh (W1) silicated Meteorite composed mainly of iron (Fe) and nickel (Ni) in the form of two alloys, kamacite and taenite. Due to their metallic makeup and extraordinary weight, iron meteorites are easily distinguished from ordinary rocks. Also, because they rarely break up in the air and suffer much less from the effects Click on Term to Read More weighing 6,100 g was purchased from a Moroccan dealer by Dr. D. Gregory in Tucson, Arizona. The Moroccan dealer had previously purchased the 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 in Alnif, Morocco. 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 analyses and classification of the type specimen of NWA 468 was completed at UCLA by J. Wasson and A. Rubin. The Largest fragment of a meteorite, typically at the time of recovery. Meteorites are commonly cut, sliced or sometimes broken thus reducing the size of the main mass and the resulting largest specimen is called the "largest known mass". Click on Term to Read More remains with the purchaser, while a 185 g specimen is maintained at the Royal Ontario Museum in Toronto, Canada.
Diagram credit: A. Ruzicka, Chemie der Erde–Study of the chemical composition of Earth and other planets, chemical processes and reactions that govern the composition of rocks and soils, and the cycles of matter and energy that transport Earth's chemical components in time and space. Click on Term to Read More, vol. 74, no. 1, p. 6 (Mar 2014)
‘Silicate-bearing iron meteorites and their implications for the evolution of asteroidal parent bodies’
click on image for a magnified view Abbreviations: TF = terrestrial Concentration or separation of one mineral, element, or isotope from an initially homogeneous system. Fractionation can occur as a mass-dependent or mass-independent process. Click on Term to Read More line, CCAM = carbonaceous Chondrites are the most common meteorites accounting for ~84% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), reduced 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 anhydrous materials mixing line; silicated iron meteorites include IAB, IIICD, IIE fractionated (IIE fr.) and IIE unfractionated (IIE unfr.), IVA, and IIIAB Puente del Zacate (PdZ); ungrouped irons (Ungr.) include Guin (G), Enon (E), NWA 468 (468), Sombrerete (S), Tucson (T), Mbosi (Mb), Bocaiuva (B), and NWA 176 (176); other meteorites include H, L and LL chondrites, winonaites, mesosiderites (meso.), main-group pallasites (MG pall.) Eagle Station pallasites (ES pall.), and pyroxene pallasites (px pall.) Research on this meteorite has been ongoing (e.g., Rubin et al., 2002 [GCA vol. 66, #20]; Bunch et al., 2005, [#2308]; Floss et al., 2005, [MAPS vol. 40, #3]; Irving et al., 2014 [#2465]; Sanborn et al., 2014 [#2032]; A. Ruzicka, 2014 [Chemie der Erde–Geochemistry]). As recognized in the Sanborn et al. (2014) abstract, a Δ17O vs. ε54Cr diagram is one of the best diagnostic tools for determining genetic (parent body) relationships among meteorites. Moreover, Sanborn et al. (2015) demonstrated that ε54Cr values are not affected by aqueous alteration. Utilizing both the ε54Cr and Δ17O values calculated for NWA 468 (Sanborn et al.  and Irving et al. , respectively), the plot on a Δ17O vs. ε54Cr diagram shows that NWA 468 lies within the field of the acapulcoite–lodranite clan, in further support of a common parent body for these meteorites. Coupled Δ17O vs. ε54Cr Diagram for Selected Meteorites
Diagram credit: Sanborn et al., 77th Meteoritical Society Meeting #5169 (2014) In their study of the The textural, mineralogical or compositional remnant within a sedimentary rock of a meteorite that fell millions of years ago and found in Ordovician limestone from Sweden. Read Tiny Traces of a Big Asteroid Breakup for a complete writeup on this subject. In picture to the left a nautiloid shell is Click on Term to Read More Österplana 065, Schmitz et al. (2016) included oxygen and chromium isotopic data for NWA 468 in a coupled Δ17O vs. ε54Cr diagram (shown below). This higher resolution diagram also clearly demonstrates that this meteorite plots within the acapulcoite–lodranite region in isotope space. Chromium vs. Oxygen Isotope Plot
click on image for a magnified view Diagram credit: Schmitz, B. et al., Nature Communications, vol. 7, p. 4 (2016, open access link)
‘A new type of solar-system material recovered from Ordovician marine A common form of calcium carbonate (CaCO3). Other common forms of CaCO3 include chalk and marble. Click on Term to Read More ‘
(https://doi.org/10.1038/ncomms11851) A comprehensive study of the H4 chondrite Grove Mountains (GRV) 020043 was conducted by Li et al. (2018). They demonstrated that the mineralogy, geochemistry, and O- and Cr-isotopic compositions of this meteorite support the reclassification to ‘Acapulcoite chondrite’, representing the chondritic, unmelted, outermost layer of the acapulcoite–lodranite parent body. They also provided clear evidence for the origination of NWA 468 on the ACA–LOD parent body, which, along with the metal-rich lodranite GRA 95209 (NASA lab photo), are considered to represent the deepest lithology (early In the context of planetary formation, the core is the central region of a large differentiated asteroid, planet or moon and made up of denser materials than the surrounding mantle and crust. For example, the cores of the Earth, the terrestrial planets and differentiated asteroids are rich in metallic iron-nickel. Click on Term to Read More segregation) of the parent body. A schematic representation of the acapulcoite–lodranite parent body was presented by Li et al. (2018): Interior Structure of the Acapulcoite–Lodranite Parent Body
Schematic diagram credit: Li et al., GCA, vol. 242, p. 96 (2018)
‘Evidence for a Multilayered Internal Structure of the Chondritic Acapulcoite–Lodranite Parent Asteroid’
(https://doi.org/10.1016/j.gca.2018.09.004) The specimen of NWA 468 shown above is a 2.45 g partial slice. The photo below shows a full slice with a close-up of the lower left corner from which the above specimen was removed. The remainder of this slice is in the collection of UCLA.
Photos courtesy of Dr. David Gregory
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