Re: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Bernd, Thanks so much for walking through this. I wish I could see every meteorite through your eyes. Very best regards, Bill -- Original message -- From: [EMAIL PROTECTED] > > What does all this mean? > > Hello Walter, Bill, and List, > > I'll try to go through this in little steps: > > > examination of the inclusion ...shows it to consist of small chondrules > > and chondrule fragments composed of very magnesian olivine (Fa1.1) > > The chondrules in the lower right part of the 32-gram slice are much smaller > than chondrules in the remaining CV3 matrix like chondrules in CO3 chondrites > that are much smaller. > > See also O.R. Norton's Encyclopedia, pp. 135-136 and p. 136, Fig. 7.19: > > "While the average chondrule-diameter of a CV is about 1 mm, the average for > a CO chondrite is about 0.15 mm". > > > small chondrules ... composed of very magnesian olivine (Fa1.1) > > O.R. Norton, 135: "most [chondrules in CO chondrites] are porphyritic > olivine chondrules with olivine made of nearly pure forsterite". > > O.R. Norton, p. 312, Appendix C, Minerals in Meteorites: > > "Forsterite = the magnesium end member of the olivine ... (Mg2SiO4)" > > The chemical formula shows it is *magnesian* olivine and Fa1.1 shows there > is hardly any trace of iron. The opposite end member is fayalite (Fe2SiO4), > the iron end member (here it is iron that is missing). > > > with marginal Fe-rich reaction zones (Fa36.9) > > Imagine a small rim around the chondrules. These outer zones reacted with > FeO-rich (iron-rich) olivine in the surronding matrix and thereby became > enriched in Fe (not just Fa1.1 [iron-poor] but Fa36.9 [iron-rich]). > > > against a porous matrix composed of felted blades of relatively > > ferroan olivine (Fa40.9-45.9) with accessory troilite and pentlandite. > > Here is what I already said the matrix is rich in olivine that contains > a lot of iron and not as much magnesium as those "magnesian chondrules". > > > This clast has the attributes of Type A/B dark inclusions ... > > Dark inclusions are lithic fragments up to about 5 cm in size. They have > been found in several CV3 chondrites, for example in Allende, Vigarano, > Leoville, etc.). Their main mineral component is fayalitic olivine. Some > are chondrule-rich, some are chondrule-free (consist almost entirely of > matrix)*. > > *Reference: > > WEISBERG M.K. et al. (1998) Fayalitic olivine in CV3 chondrite matrix > and dark inclusions: A nebular origin (MAPS 33-5, 1998, 1087-1099). > > > This clast has the attributes of *Type A/B* dark inclusions ... > > HUTCHISON R. (2004) Meteorites: A Petrologic, Chemical, and > Isotopic Synthesis (Cambridge Planetary Science Series, p. 62): > > Porphyritic chondrules may be type I and FeO-poor > or type II and FeO-rich > > They may additionally be subdivided into two categories: > > - silica-poor A > - silica-rich B > > AB is intermediate. > > > Oxygen isotope analysis ... gave replicate (= duplicate) values of: > > d17O = +0.08, -0.18; > d18O = 5.14, 4.99; > D17O = -2.63, -2.81 per mil, respectively, which plot on >the best fit line for whole rock CV chondrites. > > See O.R. Norton, p. 135 or McSWEEN H.Y. (1999) Meteorites and > Their Parent Planets, p.51: "The oxygen isotopic compositions > provide one means of classifying chondrites into clans and groups". > > When you look at these plots in Norton or McSween, you'll see that > these values are in the range for CV chondrites but very close to > the area for CM chondrites (which are much more primitive than > CVs and point toward aqueous activity and aqueous alteration on > their parent bodies. > > So this clast may represent a more hydrated relict part of a CV parent > body the other parts of which are more dehydrated due to parent body > metamorphism. > > A piece from a boundary area between more and less dehydrated > material? > > A pocket (or clast) of more primitive material embedded into the > higher metamorphosed CV3 material? > > > a specimen that clearly demonstrates what the above report describes: > > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 > > > Best wishes, > > Bernd > > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Hello List members, See also "Mineralogy of dark inclusions in CV" by Brearly & Jones in "Planetary Materials, Reviews in Mineralogy vol. 36", p3-225, which is a well-written review for CV DI, I guess. K. Ohtsuka, Tokyo - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Thursday, February 24, 2005 1:26 AM Subject: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update > > What does all this mean? > > Hello Walter, Bill, and List, > > I'll try to go through this in little steps: > > > examination of the inclusion ...shows it to consist of small chondrules > > and chondrule fragments composed of very magnesian olivine (Fa1.1) > > The chondrules in the lower right part of the 32-gram slice are much smaller > than chondrules in the remaining CV3 matrix like chondrules in CO3 chondrites > that are much smaller. > > See also O.R. Norton's Encyclopedia, pp. 135-136 and p. 136, Fig. 7.19: > > "While the average chondrule-diameter of a CV is about 1 mm, the average for > a CO chondrite is about 0.15 mm". > > > small chondrules ... composed of very magnesian olivine (Fa1.1) > > O.R. Norton, 135: "most [chondrules in CO chondrites] are porphyritic > olivine chondrules with olivine made of nearly pure forsterite". > > O.R. Norton, p. 312, Appendix C, Minerals in Meteorites: > > "Forsterite = the magnesium end member of the olivine ... (Mg2SiO4)" > > The chemical formula shows it is *magnesian* olivine and Fa1.1 shows there > is hardly any trace of iron. The opposite end member is fayalite (Fe2SiO4), > the iron end member (here it is iron that is missing). > > > with marginal Fe-rich reaction zones (Fa36.9) > > Imagine a small rim around the chondrules. These outer zones reacted with > FeO-rich (iron-rich) olivine in the surronding matrix and thereby became > enriched in Fe (not just Fa1.1 [iron-poor] but Fa36.9 [iron-rich]). > > > against a porous matrix composed of felted blades of relatively > > ferroan olivine (Fa40.9-45.9) with accessory troilite and pentlandite. > > Here is what I already said the matrix is rich in olivine that contains > a lot of iron and not as much magnesium as those "magnesian chondrules". > > > This clast has the attributes of Type A/B dark inclusions ... > > Dark inclusions are lithic fragments up to about 5 cm in size. They have > been found in several CV3 chondrites, for example in Allende, Vigarano, > Leoville, etc.). Their main mineral component is fayalitic olivine. Some > are chondrule-rich, some are chondrule-free (consist almost entirely of > matrix)*. > > *Reference: > > WEISBERG M.K. et al. (1998) Fayalitic olivine in CV3 chondrite matrix > and dark inclusions: A nebular origin (MAPS 33-5, 1998, 1087-1099). > > > This clast has the attributes of *Type A/B* dark inclusions ... > > HUTCHISON R. (2004) Meteorites: A Petrologic, Chemical, and > Isotopic Synthesis (Cambridge Planetary Science Series, p. 62): > > Porphyritic chondrules may be type I and FeO-poor > or type II and FeO-rich > > They may additionally be subdivided into two categories: > > - silica-poor A > - silica-rich B > > AB is intermediate. > > > Oxygen isotope analysis ... gave replicate (= duplicate) values of: > > d17O = +0.08, -0.18; > d18O = 5.14, 4.99; > D17O = -2.63, -2.81 per mil, respectively, which plot on >the best fit line for whole rock CV chondrites. > > See O.R. Norton, p. 135 or McSWEEN H.Y. (1999) Meteorites and > Their Parent Planets, p.51: "The oxygen isotopic compositions > provide one means of classifying chondrites into clans and groups". > > When you look at these plots in Norton or McSween, you'll see that > these values are in the range for CV chondrites but very close to > the area for CM chondrites (which are much more primitive than > CVs and point toward aqueous activity and aqueous alteration on > their parent bodies. > > So this clast may represent a more hydrated relict part of a CV parent > body the other parts of which are more dehydrated due to parent body > metamorphism. > > A piece from a boundary area between more and less dehydrated > material? > > A pocket (or clast) of more primitive material embedded into the > higher metamorphosed CV3 material? > > > a specimen that clearly demonstrates what the above report describes: > > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 > > > Best wishes, > > Bernd > > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Correction: The chemical formula shows it is *magnesian* olivine and Fa1.1 shows there is hardly any trace of iron. The opposite end member is fayalite (Fe2SiO4), the iron end member (here it is MAGNESIUM that is missing). Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NWA 3118 CV3 Chondrule-Field Update
> What does all this mean? Hello Walter, Bill, and List, I'll try to go through this in little steps: > examination of the inclusion ...shows it to consist of small chondrules > and chondrule fragments composed of very magnesian olivine (Fa1.1) The chondrules in the lower right part of the 32-gram slice are much smaller than chondrules in the remaining CV3 matrix like chondrules in CO3 chondrites that are much smaller. See also O.R. Norton's Encyclopedia, pp. 135-136 and p. 136, Fig. 7.19: "While the average chondrule-diameter of a CV is about 1 mm, the average for a CO chondrite is about 0.15 mm". > small chondrules ... composed of very magnesian olivine (Fa1.1) O.R. Norton, 135: "most [chondrules in CO chondrites] are porphyritic olivine chondrules with olivine made of nearly pure forsterite". O.R. Norton, p. 312, Appendix C, Minerals in Meteorites: "Forsterite = the magnesium end member of the olivine ... (Mg2SiO4)" The chemical formula shows it is *magnesian* olivine and Fa1.1 shows there is hardly any trace of iron. The opposite end member is fayalite (Fe2SiO4), the iron end member (here it is iron that is missing). > with marginal Fe-rich reaction zones (Fa36.9) Imagine a small rim around the chondrules. These outer zones reacted with FeO-rich (iron-rich) olivine in the surronding matrix and thereby became enriched in Fe (not just Fa1.1 [iron-poor] but Fa36.9 [iron-rich]). > against a porous matrix composed of felted blades of relatively > ferroan olivine (Fa40.9-45.9) with accessory troilite and pentlandite. Here is what I already said the matrix is rich in olivine that contains a lot of iron and not as much magnesium as those "magnesian chondrules". > This clast has the attributes of Type A/B dark inclusions ... Dark inclusions are lithic fragments up to about 5 cm in size. They have been found in several CV3 chondrites, for example in Allende, Vigarano, Leoville, etc.). Their main mineral component is fayalitic olivine. Some are chondrule-rich, some are chondrule-free (consist almost entirely of matrix)*. *Reference: WEISBERG M.K. et al. (1998) Fayalitic olivine in CV3 chondrite matrix and dark inclusions: A nebular origin (MAPS 33-5, 1998, 1087-1099). > This clast has the attributes of *Type A/B* dark inclusions ... HUTCHISON R. (2004) Meteorites: A Petrologic, Chemical, and Isotopic Synthesis (Cambridge Planetary Science Series, p. 62): Porphyritic chondrules may be type I and FeO-poor or type II and FeO-rich They may additionally be subdivided into two categories: - silica-poor A - silica-rich B AB is intermediate. > Oxygen isotope analysis ... gave replicate (= duplicate) values of: d17O = +0.08, -0.18; d18O = 5.14, 4.99; D17O = -2.63, -2.81 per mil, respectively, which plot on the best fit line for whole rock CV chondrites. See O.R. Norton, p. 135 or McSWEEN H.Y. (1999) Meteorites and Their Parent Planets, p.51: "The oxygen isotopic compositions provide one means of classifying chondrites into clans and groups". When you look at these plots in Norton or McSween, you'll see that these values are in the range for CV chondrites but very close to the area for CM chondrites (which are much more primitive than CVs and point toward aqueous activity and aqueous alteration on their parent bodies. So this clast may represent a more hydrated relict part of a CV parent body the other parts of which are more dehydrated due to parent body metamorphism. A piece from a boundary area between more and less dehydrated material? A pocket (or clast) of more primitive material embedded into the higher metamorphosed CV3 material? > a specimen that clearly demonstrates what the above report describes: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 Best wishes, Bernd __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Hi Adam, What does all this mean? -Walter - - Original Message - From: "Adam Hupe" <[EMAIL PROTECTED]> To: Sent: Tuesday, February 22, 2005 3:43 PM Subject: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update > Dear List Members, > > There was some question about the strange clasts in the NWA 3118 CV3s. They > looked like CO3 chondrule-fields to me so I had them studied. Oxygen > isotope studies were performed at Carnegie and Petrologic/Microprobe work > was performed at UW. Here are the most interesting results: > > Northwest Africa 3118, additional data > Morocco > Purchased 2003 December > CV3 chondrite > A small stone representing part of the main mass held by A. and G. Hupé > (Hupé) was found to contain a dark inclusion measuring approximately 9 cm by > 2.5 cm by 1 cm. Microprobe examination of the inclusion by A. Irving and S. > Kuehner (UWS) shows it to consist of small chondrules and chondrule > fragments composed of very magnesian olivine (Fa1.1) with marginal Fe-rich > reaction zones (Fa36.9) against a porous matrix composed of felted blades of > relatively ferroan olivine (Fa40.9-45.9) with accessory troilite and > pentlandite. This clast has the attributes of Type A/B dark inclusions > described by Brearley and Jones (1998, p. 3-227), and the textures suggest > that it may have formed by partial sublimation of original chondrules and > re-condensation. Oxygen isotope analysis by D. Rumble (CIW) of acid-washed > whole inclusion material by laser fluorination gave replicate values of ?17O > = +0.08, -0.18; ?18O = 5.14, 4.99; ?17O = -2.63, -2.81 per mil, > respectively, which plot on the best fit line for whole rock CV chondrites. > > Here is a specimen that clearly demonstrates what the above report > describes: > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 > > I hope you found the above data as interesting as I did. > > Kind Regards, > > > Adam Hupe > The Hupe Collection > Team LunarRock > IMCA 2185 > [EMAIL PROTECTED] > > > > > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Adam, Does this data apply to all NWA 3118 or only your material? I don't understand a lot of these analysis results. Can anyone translate the more technical aspects of this lab report in a way that means something to the average person? Thanks, Bill -- Original message -- From: "Adam Hupe" <[EMAIL PROTECTED]> > Dear List Members, > > There was some question about the strange clasts in the NWA 3118 CV3s. They > looked like CO3 chondrule-fields to me so I had them studied. Oxygen > isotope studies were performed at Carnegie and Petrologic/Microprobe work > was performed at UW. Here are the most interesting results: > > Northwest Africa 3118, additional data > Morocco > Purchased 2003 December > CV3 chondrite > A small stone representing part of the main mass held by A. and G. Hupé > (Hupé) was found to contain a dark inclusion measuring approximately 9 cm by > 2.5 cm by 1 cm. Microprobe examination of the inclusion by A. Irving and S. > Kuehner (UWS) shows it to consist of small chondrules and chondrule > fragments composed of very magnesian olivine (Fa1.1) with marginal Fe-rich > reaction zones (Fa36.9) against a porous matrix composed of felted blades of > relatively ferroan olivine (Fa40.9-45.9) with accessory troilite and > pentlandite. This clast has the attributes of Type A/B dark inclusions > described by Brearley and Jones (1998, p. 3-227), and the textures suggest > that it may have formed by partial sublimation of original chondrules and > re-condensation. Oxygen isotope analysis by D. Rumble (CIW) of acid-washed > whole inclusion material by laser fluorination gave replicate values of ?17O > = +0.08, -0.18; ?18O = 5.14, 4.99; ?17O = -2.63, -2.81 per mil, > respectively, which plot on the best fit line for whole rock CV chondrites. > > Here is a specimen that clearly demonstrates what the above report > describes: > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 > > I hope you found the above data as interesting as I did. > > Kind Regards, > > > Adam Hupe > The Hupe Collection > Team LunarRock > IMCA 2185 > [EMAIL PROTECTED] > > > > > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NWA 3118 CV3 Chondrule-Field Update
Dear List Members, There was some question about the strange clasts in the NWA 3118 CV3s. They looked like CO3 chondrule-fields to me so I had them studied. Oxygen isotope studies were performed at Carnegie and Petrologic/Microprobe work was performed at UW. Here are the most interesting results: Northwest Africa 3118, additional data Morocco Purchased 2003 December CV3 chondrite A small stone representing part of the main mass held by A. and G. Hupé (Hupé) was found to contain a dark inclusion measuring approximately 9 cm by 2.5 cm by 1 cm. Microprobe examination of the inclusion by A. Irving and S. Kuehner (UWS) shows it to consist of small chondrules and chondrule fragments composed of very magnesian olivine (Fa1.1) with marginal Fe-rich reaction zones (Fa36.9) against a porous matrix composed of felted blades of relatively ferroan olivine (Fa40.9-45.9) with accessory troilite and pentlandite. This clast has the attributes of Type A/B dark inclusions described by Brearley and Jones (1998, p. 3-227), and the textures suggest that it may have formed by partial sublimation of original chondrules and re-condensation. Oxygen isotope analysis by D. Rumble (CIW) of acid-washed whole inclusion material by laser fluorination gave replicate values of ?17O = +0.08, -0.18; ?18O = 5.14, 4.99; ?17O = -2.63, -2.81 per mil, respectively, which plot on the best fit line for whole rock CV chondrites. Here is a specimen that clearly demonstrates what the above report describes: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6513101418 I hope you found the above data as interesting as I did. Kind Regards, Adam Hupe The Hupe Collection Team LunarRock IMCA 2185 [EMAIL PROTECTED] __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
