The Paris meteorite, the least altered CM chondrite so far Roger H. Hewins a,b,⇑ , Miche `le Bourot-Denise a , Brigitte Zanda a , Hugues Leroux c , Jean-Alix Barrat d , Munir Humayun e , Christa Go ¨pel f , Richard C. Greenwood g , Ian A. Franchi g , Sylvain Pont a , Jean-Pierre Lorand h , Ce ´cile Courne `de i Je ´ro ˆ me Gattacceca i,j , Pierre Rochette i , Maı ¨a Kuga k , Yves Marrocchi k Bernard Marty k a Laboratoire de Mine ´ralogie et Cosmochimie du Muse ´um, MNHN and CNRS UMR 7202, 75005 Paris, France b Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA c Unite ´ Mate ´riaux et Transformations, Universite ´ Lille 1 and CNRS, UMR 8207, F-59655 Villeneuve d’Ascq, France d Universite ´ Europe ´enne de Bretagne and CNRS UMR 6538, U.B.O-I.U.E.M., 29280 Plouzane ´ Cedex, France e Department of Earth, Ocean and Atmospheric Science and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA f Institut de Physique du Globe de Paris, Sorbonne Paris Cite ´, Universite ´ Paris Diderot, UMR 7154 CNRS, F-75005 Paris, France g PSS, Open University, Walton Hall, Milton Keynes MK7 6AA, UK h Laboratoire de Plane ´tologie et Ge ´odynamique LPG Nantes – UMR CNRS 6112, 44322 Nantes Cedex 3, France i CNRS/Aix-Marseille Universite ´, CEREGE UM34, 13545 Aix-en-Provence, France j Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA k Universite ´ Lorraine and CNRS, CRPG, UPR 2300, Vandoeuvre les Nancy F-54501, France Received 13 February 2013; accepted in revised form 14 September 2013; Available online 8 October 2013 Abstract The Paris chondrite provides an excellent opportunity to study CM chondrules and refractory inclusions in a more pristine state than currently possible from other CMs, and to investigate the earliest stages of aqueous alteration captured within a single CM bulk composition. It was found in the effects of a former colonial mining engineer and may have been an observed fall. The texture, mineralogy, petrography, magnetic properties and chemical and isotopic compositions are consistent with classification as a CM2 chondrite. There are 45 vol.% high-temperature components mainly Type I chondrules (with olivine mostly Fa 0–2, mean Fa 0.9 ) with granular textures because of low mesostasis abundances. Type II chondrules contain olivine Fa 7 to Fa 76 . These are dominantly of Type IIA, but there are IIAB and IIB chondrules, II(A)B chondrules with minor highly ferroan olivine, and IIA(C) with augite as the only pyroxene. The refractory inclusions in Paris are amoeboid olivine aggre- gates (AOAs) and fine-grained spinel-rich Ca–Al-rich inclusions (CAIs). The CAI phases formed in the sequence hibonite, perovskite, grossite, spinel, gehlenite, anorthite, diopside/fassaite and forsterite. The most refractory phases are embedded in spinel, which also occurs as massive nodules. Refractory metal nuggets are found in many CAI and refractory platinum group element abundances (PGE) decrease following the observed condensation sequences of their host phases. Mn–Cr iso- tope measurements of mineral separates from Paris define a regression line with a slope of 53 Mn/ 55 Mn = (5.76 ± 0.76)  10 6 . If we interpret Cr isotopic systematics as dating Paris components, particularly the chondrules, the age is 4566.44 ± 0.66 Myr, which is close to the age of CAI and puts new constraints on the early evolution of the solar system. Eleven individual Paris samples define an O isotope mixing line that passes through CM2 and CO3 falls and indicates that Paris is a very fresh sample, with variation explained by local differences in the extent of alteration. The anhydrous precursor to the CM2s was CO3-like, but the two groups differed in that the CMs accreted a higher proportion of water. Paris has little matrix (47%, plus 8% fine 0016-7037/$ - see front matter Ó 2013 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.gca.2013.09.014 ⇑ Corresponding author at: Laboratoire de Mine ´ralogie et Cosmochimie du Muse ´um, MNHN and CNRS UMR 7202, 61 rue Buffon, 75005 Paris, France. Tel.: +33 1 4079 3769; fax: +31 4079 5772. E-mail address: hewins@rci.rutgers.edu (R.H. Hewins). www.elsevier.com/locate/gca Available online at www.sciencedirect.com ScienceDirect Geochimica et Cosmochimica Acta 124 (2014) 190–222