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Home Antarctic MeteoritesAntarctic Meteorite NewslettersAMN 44,2 Program News
Volume 44 No. 2 – September 2021

Program News

Curator Comments

Kevin Righter, NASA-JSC

We announce 90 newly classified Antarctic meteorites from the 2017, 2018, and 2019 ANSMET collection years, including the first group examined from the Dominion Range 2019-2020 team. Among this group of 90 are a brecciated eucrite, a ureilite, seven CO3, two CM2, and one CK chondrite, as well as an unequilibrated H3, and two L melt breccias (one heavily shocked). Antarctic meteorite program staff at both the Smithsonian Institution and NASA Johnson Space Center have been working under unusual conditions of limited access to the cleanrooms, analytical labs, and office spaces to assemble all the information reported in this newsletter. That we have a robust Fall 2021 newsletter is entirely due to admirable efforts at both institutions, coordinating the samples and work in an improvised and safe manner. We also report some significant pairing re-assessments and re-classifications, the details of which are given below. Finally, we announce the availability of XCT data from 15 of our carbonaceous chondrites. These data were acquired to address issues of pairing, classification, and heterogeneity, and we also want to make them available to the community, as announced here.

Pairing re-assessments
a) unequilibrated ordinary chondrites

We have recently done a systematic re-assessment of pairing relations among unequilibrated ordinary chondrites from 4 dense collection areas in Antarctica (Righter et al., 2021a). Some of these have been paired for many years, but the discovery of distinct characteristics of individual members of the groups have led to both uncertainty in the members of pairing groups, as well as speculation that some rare or precious samples might be "hidden" in these groups. To identify more rare or interesting meteorites, and update the pairing groups as best as possible, Cr contents of olivines in Type II chondrules have been measured in many of these samples. Upon identification of new groupings and unique samples, we propose the following new classifications (while also noting that many classifications of samples from these dense collection areas remain unchanged). Paired samples are grouped below; some samples have been reclassified but are not paired with any others.

  • EET 83274 - L3.6 to L3.2

  • EET 90066 - L3.3 to L3.00
  • EET 90161 - L3.0 to L3.00
  • EET 90261 - L3.4 to L3.00
  • EET 90909 - L3.6 to L3.00

  • EET 87735 - L3.4 to L3.05
  • EET 90080 - L3.4 to L3.05
  • EET 90519 - L3.6 to L3.05
  • EET 90916 - L3.6 to L3.05
  • EET 90628 - L3.4 to L3.10

  • EET 92100 - L3.4 to L3.00

  • EET 96015 - L3.4 to L3.15
  • EET 96216 - L3.8 to L3.15

  • LEW 86134 - L3.0 to L3.05

  • LEW 87208 - L3.4 to L3.00

  • LEW 97202 - L3.4 to L3.05

  • LEW 87248 - L3.5 to L3.15
  • LEW 87284 - L3.5 to L3.15
  • LEW 88254 - L3.4 to L3.15
  • LEW 85434 - L3.4 to L3.15
  • LEW 85437 - L3.4 to L3.15
  • LEW 88462 - L3.7 to L3.15

  • LEW 86207 - L3.2 to L3.2
  • LEW 86102 - L3.4 to L3.2
  • LEW 88634 - L3.4 to L3.2
  • LEW 88520 - L3.5 to L3.2
  • LEW 86018 - L3.1 to L3.2
  • LEW 86144 - L3.0 to L3.2
  • LEW 86158 - L3.0 to L3.2
  • LEW 86270 - L3.1 to L3.2

  • GRO 95558 - L3.5 to L3.05

  • GRO 06054 - L3.6 to L3.05

  • GRO 03015 - L3.6 to L3.10
  • GRO 03061 - L3.6 to L3.10

  • GRO 95502 - L3.2 to L3.2
  • GRO 95504 - L3.5 to L3.2
  • GRO 95512 - L3.5 to L3.2
  • GRO 95539 - L3.1 to L3.2
  • GRO 95542 - L3.5 to L3.2
  • GRO 95545 - L3.5 to L3.2
  • GRO 95544 - L3.2 to L3.2
  • GRO 95550 - L3.5 to L3.2
  • GRO 95546 - L3.8 to L3.2

  • GRO 95505 - L3.4 to L3.2

  • MET 00452 - L(LL)3.05 - no change
  • MET 00526 - L(LL)3.05 - no change
  • MET 00621 - L3.6 to L(LL)3.05

  • MET 96503 - L3.10 - no change
  • MET 96515 - L3.5 to L3.10
  • MET 01051 - L3.6 to L3.10
  • MET 01056 - L3.6 to L3.10
  • MET 01057 - L3.6 to L3.10

  • MET 00506 - H3.4 to H3.10
  • MET 00552 - H3.4 to H3.10
  • MET 00607 - H3.4 to H3.10

b) Dominion Range CO3 chondrites (Righter et al., 2021b)

A large pairing group of CO3 chondrites from the Dominion Range was recognized among the 2008 (4) and subsequent collection years (additional 14 plus any newly collected in 2019-2020). As data was acquired by various scientists studying individual samples, it has become clear that DOM 08006 is more primitive than other members of this group. Because it is a large group of samples, and identification of additional primitive material is of high priority, we have undertaken a systematic look at these CO3s to make a re-assessment of pairing. We combine Cr contents of olivine from Type II chondrules with H, C, N bulk and isotopic measurements (C. Alexander and D. Foustoukos), and 21Ne cosmic ray exposure age (CRE) dates (H. Busemann). Preliminary results are reported in the 2021 Meteoritical Society meeting (Righter et al., 2021b) and summarized here with any necessary pairing adjustments. We will present an additional update in a future newsletter regarding the rest of the DOM 18 and 19 samples not yet analyzed.

Two of the samples are among the lowest grade, un-equilibrated CO3, based on Cr contents of olivines, high pre-solar grain contents, and distinct inclusions, and also have distinctly higher CRE ages of ~25 Ma. (Righter et al., 2021b; Davidson et al., 2019; Nittler et al., 2018; Simon and Grossman, 2015). Therefore, they will be paired together:

  • DOM 08006 - CO3.00
  • DOM 10847 - CO3.00

Two of the samples have very high matrix contents, distinct H, C, N bulk and isotopic compositions, and have very young CRE age (2.5-2.6 Ma), all consistent with CM2 chondrites:

  • DOM 10121 - CM2
  • DOM 10299 - CM2

One sample has unique H, C, N bulk and isotopic compositions and CRE age (5.0 Ma), all indicating that it is not a member of either of the other CO3 pairing groups. We thus have unpaired it with any others:

  • DOM 14359 - CO3

The following other DOM samples are part of the main pairing group of CO3 chondrites that have a similar H, C, N bulk and isotopic composition and CRE age of 11-12 Ma.

  • DOM 08004 - no change
  • DOM 08139 - no change
  • DOM 08351 - no change
  • DOM 10101 - no change
  • DOM 10104 - no change
  • DOM 10900 - no change
  • DOM 14019 - no change
  • DOM 14127 - no change
  • DOM 14305 - no change

Additional note: DOM 18019, 069, 070, and 286 and the new DOM19 COs announced in this newsletter (DOM 19034, DOM 19049, DOM 19068, DOM 19099, DOM 19170, and DOM 19179) will be evaluated with respect to these groups.


Several eucrites from our collection will be re-classified based on data reported by Mittlefehldt et al. (2021): EET 87520, ALH 85001, and EET 87548.

a) EET 87520

Detailed analyses of EET 87520 and EET 87542 by Mittlefehldt et al. (2021) show that the original microprobe analyses reported for EET 87520 were most likely mistakenly acquired on a section of EET 87542. EET 87520 was (and is) classified as "Eucrite-Mg rich" because of the originally reported pyroxene compositions that were more magnesian than those for typical basaltic eucrites like Sioux County. However, new analyses reported by Mittlefehldt et al. (2021) show that EET 87520 pyroxene compositions are, in fact, as ferroan as those of Sioux County. The petrographic description of this eucrite in the initial description (Antarctic Meteorite Newsletter vol. 11, no. 2, 1988) is correct. We therefore will reclassify EET 87520 as an unbrecciated eucrite, which was its initial classification before reclassification as eucrite-Mg rich (Antarctic Meteorite Newsletter vol. 17, no. 1, 1994).

b) ALH 85001 and EET 87548

Two meteorites are classified as eucrite-Mg rich in the Meteoritical Bulletin Database: ALH 85001 and EET 87548. This classification type was designed to be used for those eucrites for which definitive evidence of a cumulate origin were not yet available. In the late 1980s, such evidence was not available and "eucrite-Mg rich" was an appropriate designation. However, now there is ample data to classify these samples as "Eucrite-cumulate", including both trace elements, and textures, mineral compositions and bulk sample compositions for these rocks are all consistent with classification as cumulate eucrites (Mittlefehldt and Lindstrom, 2003; Warren et al., 2009); we therefore will reclassify both as "Eucrite-cumulate".


Davidson, J., Alexander, C. M. D., Stroud, R. M., Busemann, H., & Nittler, L. R. (2019) Mineralogy and petrology of Dominion Range 08006: A very primitive CO3 carbonaceous chondrite. Geochimica et Cosmochimica Acta 265, 259-278.

Mittlefehldt, D.W., Greenwood, R.C., Berger, E.L., Le, L., Peng, Z.X., and Ross, D.K. (2021) Eucrite-type Achondrites: Petrology and Oxygen-Isotope Compositions. Meteoritics & Planetary Science, in press.

Mittlefehldt, D. W., & Lindstrom, M. M. (2003) Geochemistry of eucrites: Genesis of basaltic eucrites, and Hf and Ta as petrogenetic indicators for altered Antarctic eucrites. Geochimica et Cosmochimica Acta 67, 1911-1934.

Nittler, L. R., Alexander, C. M. D., Davidson, J., Riebe, M. E., Stroud, R. M., & Wang, J. (2018) High abundances of presolar grains and 15N-rich organic matter in CO3. 0 chondrite Dominion Range 08006. Geochimica et Cosmochimica Acta 226, 107-131.

Righter, K., Schutt, J., Lunning, N., Harvey, R., & Karner, J. (2021a) Identification and pairing reassessment of unequilibrated ordinary chondrites from four Antarctic dense collection areas. Meteoritics & Planetary Science 56, 1556-1578.

Righter K., Alexander, C., Foustoukos, D., Mertens, C.A.K., Busemann, H., Schutt, J. (2021b) Pairing Relations Within CO3 Chondrites Recovered at the Dominion Range and Miller Range, Transantarctic Mountains, 84th Annual Meteoritical Society meeting, Chicago, abstract #6191.

Simon, S. B., & Grossman, L. (2015) Refractory inclusions in the pristine carbonaceous chondrites DOM 08004 and DOM 08006. Meteoritics & Planetary Science 50, 1032-1049.

Warren, P. H., Kallemeyn, G. W., Huber, H., Ulff-Møller, F., & Choe, W. (2009) Siderophile and other geochemical constraints on mixing relationships among HED-meteoritic breccias. Geochimica et Cosmochimica Acta 73, 5918-5943.

Newly available XCT scans

During 2020 and 2021 we have obtained XCT scans for a number of chondrites to help us address curatorial issues of identifying multiple lithologies, look for heterogeneity in general, textural variations such as lineation or brecciation, and in some cases help to address pairing questions. The following samples have new XCT scan tiff stack movies added to their petrographic description pages.

  • CM - assessing multiple lithologies
  • ALH 83100, 98
  • ALH 84033, 0

  • CO - to assess heterogeneity and also pairing
  • MIL 07343, 0
  • MIL 090038, 11
  • DOM 08006, 106
  • DOM 08351, 0
  • DOM 10847, 8

  • CV - to assess heterogeneity, pairing, brecciation
  • MIL 07002, 44
  • MIL 07671, 26
  • RBT 04133, 51
  • GRA 06101, 29
  • GRO 95652, 34
  • LAP 02206, 77
  • LAR 12002, 61
  • MET 00430,39


Jim Karner, University of Utah

We've all had to deal with the disappointment of cancelled or completely transformed events since the pandemic hit full swing 18 months ago. Professionally, we've all been affected by the myriad cancellations, terminations, and suspensions of in-person classes, conferences, meetings, field work and laboratory time. Privately, it has not been much better - my beer-league hockey team was perched at number one going into the 2020 playoffs before dealing with the heartbreak of a completely cancelled season! A tough break for the Western Door team of the Salt Lake County, Division 2 Adult Hockey League, for sure.

Thus it is probably not a surprise that the 2021-22 ANSMET season has been cancelled. We predicted this about half a year ago, as the US Antarctic Program (USAP) had started to make a slow recovery from the pandemic but is still dry on critical resources like fuel and logistics. This coming season, the USAP will run at a reduced capacity and mainly support activities that are 1) required for safe and continuous operation of all three US stations and resupply of those stations, as well as 2) needed to minimize irreversible impacts on science, construction, and future operations. ANSMET falls into a third tier of activities not included in the above categories- USAP expects to support a very small number of these in the upcoming season, but ANSMET is not one of them.

We look forward to our next season in the field, which hopefully will be 2022-23! Seems like a long way off but we've already started thinking about our return to a final (?) season at Davis-Ward and a return (last visited in 2003) to the main Dominion Range icefield as our next target. We'll continue to plan for that next field season and also take the time to evaluate, replace, and upgrade vital equipment as well as turn field data and observations into scientific publications. I'll also continue to read, evaluate and file those volunteer application letters.

Genesis first virtual science meeting
Figure 1: Indoors, absolutely no social distancing, and no masks?!? That was ANSMET life pre-pandemic.

Report from the Smithsonian

Cari Corrigan, Geologist (Dept. of Mineral Sci.)

The Smithsonian, at the time of this printing, has been reopened to the public after COVID closures. Staff, however, remain on extensive telework, severely restricting access. This newsletter is a return to a more normal classification structure, though analyses, photographs and observations were still conducted on the limited occasions we were able to enter the Museum. As conducting lab work is high on the priority list, we were able to classify 90 meteorites using both electron microprobe and EDS analyses for this newsletter. Our collaborative method of analyzing, describing, and classifying meteorites was still restricted due to our inability to spend extended periods of time in the same room and discuss the features of each meteorite together as we would usually do.

In more positive news, the Smithsonian has ordered a new scanning electron microscope to be delivered in October 2021. This new instrument, once installed certified, will eventually be used to classify ordinary chondrites using the dual EDS system.

Our collections are still closed to loans and will likely remain so until later in 2021 or early 2022. Once we return to work on a regular basis, we will work diligently to fulfill the recommended requests. We sincerely hope that you and your families are all safe and well.