Der Meteorit von "Paris"

[pallasit]

Hallo Forum,

Ein kleiner Bericht und ein recht gutes Video über den Meteoriten von "Paris":
http://de.euronews.net/2010/02/17/die-unglaubliche-geschichte-des-meteoriten-paris/

 

[gsac]

Ein kleiner Bericht und ein recht gutes Video über den Meteoriten von "Paris":
http://de.euronews.net/2010/02/17/die-unglaubliche-geschichte-des-meteoriten-paris/

Immer wieder auch schön, wenn man mal ein Gesicht zum Namen sieht.
http://cambridge.org/us/catalogue/catalogue.asp?isbn=0521799406

In diesem Falle Madame B. Zanda, die Hüterin der meteoritischen (...und
vielleicht nicht nur dieser?) Steine im Muséum National d'Histoire Naturelle
in Paris.

Alex

[karmaka]

Dieser Thread verdient eine 'Wiederbelebung'.

Was für ein Geschichte!

Wer von uns wäre nicht gerne an Jean-Jacques Corrés Stelle gewesen?

Das oben verlinkte Video ist leider nicht mehr verfügbar, aber es dürfte sich um diesen Bericht der BBC World News (10.2.2010) gehandelt haben:

VIDEO-LINK

Kürzlich fand ich dann doch eher zufällig Brigitte Zandas Auftritt in der französischen Nachrichtensendung JT 20H am 2.2.2010 auf France 2

VIDEO-LINK

Eine interessante französische Lektüre, einschließlich einer abenteuerlichen typografischen Gestaltung,
bietet auch dieses Kommuniqué (es soll tatsächlich so geschrieben werden):

Man kann sich aber auch nur an den schönen Bildern erfreuen.

PDF-LINK

Hier noch ein Paper zu 'Paris' (ich habe immer noch Schwierigkeiten mit diesem Namen)

PARIS: THE SLIGHTLY ALTERED, SLIGHTLY
METAMORPHOSED CM THAT BRIDGES THE GAP
BETWEEN CMs AND COs.

PDF-LINK

Hier noch drei neue Veröffentlichungen zu 'Paris'

3/2013

A TEM INVESTIGATION OF THE FINE GRAINED MATRIX OF THE PARIS CM CHONDRITE
PDF-LINK

Hydrogen Isotopic Compositions and Water Contents in Type I Chondrules of Paris CM Chondrite
PDF-LINK

2012

EARLY STAGES OF HYDROTHERMAL ALTERATION IN ANOMALOUS PRIMITIVE CCs NWA 5958 & PARIS
PDF-LINK

 

Martin

[karmaka]

Ein neues Paper zum interessanten 'Paris' Meteorit

The Paris meteorite, the least altered CM chondrite so far

Roger H. Hewins, Michèle Bourot-Denise, Brigitte Zanda, Hugues Leroux, Jean-Alix Barrat, Munir Humayun, Christa Göpel,
Richard C. Greenwood, Ian A. Franchi, Sylvain Pont, Jean-Pierre Lorand, Cécile Cournède, Jérôme Gattacceca, Pierre Rochette, Maïa Kuga,Yves Marrocchi,Bernard Marty

LINK

Geochimica et Cosmochimica Acta
Volume 124, 1 January 2014, Pages 190–222

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 Fa0–2, mean Fa0.9) with granular textures because of low mesostasis abundances. Type II chondrules contain olivine Fa7 to Fa76. 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 aggregates (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 isotope measurements of mineral separates from Paris define a regression line with a slope of 53Mn/55Mn = (5.76 ± 0.76) × 106. 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 grained rims) and is less altered than other CM chondrites. Chondrule silicates (except mesostasis), CAI phases, submicron forsterite and amorphous silicate in the matrix are all well preserved in the freshest domains, and there is abundant metal preserved (metal alteration stage 1 of Palmer and Lauretta (2011)). Metal and sulfide compositions and textures correspond to the least heated or equilibrated CM chondrites, Category A of Kimura et al. (2011). The composition of tochilinite–cronstedtite intergrowths gives a PCP index of ∼2.9. Cronstedtite is more abundant in the more altered zones whereas in normal highly altered CM chondrites, with petrologic subtype 2.6–2.0 based on the S/SiO2 and ∑FeO/SiO2 ratios in PCP or tochilinite–cronstedtite intergrowths (Rubin et al., 2007), cronstedtite is destroyed by alteration. The matrix in fresh zones has CI chondritic volatile element abundances, but interactions between matrix and chondrules occurred during alteration, modifying the volatile element abundances in the altered zones. Paris has higher trapped Ne contents, more primitive organic compounds, and more primitive organic material than other CMs. There are gradational contacts between domains of different degree of alteration, on the scale of ∼1 cm, but also highly altered clasts, suggesting mainly a water-limited style of alteration, with no significant metamorphic reheating.

[karmaka]

Neues zu 'Paris'

The Paris CM chondrite: Secondary minerals and asteroidal processing

Yves Marrocchi, Matthieu Gounelle,  Ingrid Blanchard, Florent Caste, Anton T. Kearsley

Article first published online: 12 JUN 2014
Meteoritics & Planetary Science. doi: 10.1111/maps.12329

LINK

We report a petrographic and mineralogical survey of Paris, a new CM chondrite considered to be the least-altered CM identified so far (Hewins et al. 2014). Compared to other CMs, Paris exhibits (1) a higher concentration of Fe-Ni metal beads, with nickel contents in the range 4.1–8.1 wt%; (2) the systematic presence of thin lamellae and tiny blebs of pentlandite in pyrrhotite grains; and (3) ubiquitous tochilinite/cronstedtite associations with higher FeO/SiO2 and S/SiO2 ratios. In addition, Paris shows the highest concentration of trapped 36Ar reported so far for a CM chondrite (Hewins et al. 2014). In combination with the findings of previous studies, our data confirm the reliability of (1) the alteration sequence based on the chemical composition of tochilinite/cronstedtite associations to quantify the fluid alteration processes and (2) the use of Cr content variability in type II ferroan chondrule olivine as a proxy of thermal metamorphism. In contrast, the scales based on (1) the Fe3+ content of serpentine in the matrix to estimate the degree of aqueous alteration and (2) the chemical composition of Fe-Ni metal beads for quantifying the intensity of the thermal metamorphism are not supported by the characteristics of Paris. It also appears that the amount of trapped 36Ar is a sensitive indicator of the secondary alteration modifications experienced by chondrites, for both aqueous alteration and thermal metamorphism. Considering Paris, our data suggest that this chondrite should be classified as type 2.7 as it suffered limited but significant fluid alteration and only mild thermal metamorphism. These results point out that two separated scales should be used to quantify the degree of the respective role of aqueous alteration and thermal metamorphism in establishing the characteristics of CM chondrites.

[karmaka]

Für alle, die über die Feiertage einen Abstecher nach Paris planen.

FOTO

Paris (links), neben Orgueil (Mitte) und Allende (rechts) im Rahmen der heute im Muséum national d’Histoire naturelle eröffneten Ausstellung "Les Trésors de la Terre", die noch bis zum 31.12. läuft.

[karmaka]

Spannendes zu 'Paris' aus London und Paris

The amino acid and hydrocarbon contents of the Paris meteorite: Insights into the most primitive CM chondrite

Zita Martins, Paola Modica, Brigitte Zanda and Louis Le Sergeant d'Hendecourt

Meteoritics & Planetary Science
doi: 10.1111/maps.12442

LINK

The Paris meteorite is one of the most primitive carbonaceous chondrites. It is reported to be the least aqueously altered CM chondrite, and to have experienced only weak thermal metamorphism. We have analyzed for the first time the amino acid and hydrocarbon contents of this pristine meteorite by gas chromatography–mass spectrometry (GC–MS). When plotting the relative amino acids abundances of several CM chondrites according to the increasing hydrothermal scale (petrologic subtypes), from the CM2.7/2.8 Paris to the CM2.0 MET 01070, Paris has the lowest relative abundance of β-alanine/glycine (0.15), which fits with the relative abundances of β-alanine/glycine increasing with increasing aqueous alteration for CM chondrites. These results confirm the influence of aqueous alteration on the amino acid abundances and distribution. The amino acid analysis shows that the isovaline detected in this meteorite is racemic (d/l = 0.99 ± 0.08; l-enantiomer excess = 0.35 ± 0.5%; corrected d/l = 1.03; corrected l-enantiomer excess = −1.4 ± 2.6%). The identified hydrocarbons show that Paris has n-alkanes ranging from C16 to C25 and 3- to 5-ring nonalkylated polycyclic aromatic hydrocarbons (PAHs). The lack of alkylated PAHs in Paris seems to be also related to this low degree of aqueous alteration on its parent body. The extraterrestrial hydrocarbon content, suggested by the absence of any biomarker, may well have a presolar origin. The chemistry of the Paris meteorite may thus be closely related to the early stages of the solar nebula with a contribution from interstellar (molecular cloud) precursors.

[karmaka]

An American in on Paris - Rubin statt Gershwin

Ein weiterer lesenswerter Beitrag zu 'Paris':

An American on Paris: Extent of aqueous alteration of a CM chondrite and the petrography of its refractory and amoeboid olivine inclusions

Rubin, A. E.

Meteoritics & Planetary Science. doi: 10.1111/maps.12482

LINK