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Home Antarctic MeteoritesAntarctic Meteorite NewslettersAMN 41,1 Program News
Volume 41 No. 2 – September 2018

Program News

Curator Comments

Kevin Righter, NASA-JSC

This newsletter reports samples from the 2014, 2015, 2016, and 2017 ANSMET seasons, including the first from the most recent 2017–2018 season to the Grosvenor Mountains and Amundsen Glacier areas.

Reported here are numerous (14) HED meteorites (including several pairing groups), 3 irons, 10 carbonaceous chondrites, a low FeO ordinary chondrite, and two H3.5 chondrites. The eucrites have been assigned pairing groups as best as possible given the macroscopic, microscopic, and mineral compositional data, but should be treated with caution. Any detailed petrologic work on these pairing groups should try to verify or confirm the pairings. New slices of these meteorites might reveal previously unrecognized lithologies or textures, which would than require a revision of the pairing relations.

In addition to the newly classified samples, there are some reclassifications: a) an unusual achondrite DOM 14289 reclassified from a lodranite to a QUE 93148–like ungrouped achondrite with possible affinities with HEDs, and b) over 300 equilibrated ordinary chondrites from the Dominion Range for which our magnetic susceptibility data indicates reclassification. We also report a pairing update for LAP 031047 and LAP 03788.

Updated classification for DOM 14289:

Original classification notes:

This meteorite was examined in a thin section (,2) which contained only silicate material and a thick section (,4) dominated by metal with minor silicates and chromite. As a whole, the meteorite is metal dominated. Silicates are coarse grained, with individual grains reaching up to 3 mm. Pyroxenes exhibit approximately 2 micron scale striations of high birefringence. Chromites reach up to 1.4 mm. The metal exhibits partial swathing kamacite adjacent to silicates and chromite with plessite dominating most of the section. Metal and sulfide inclusions occur within the chromites. Compositionally, olivines are Fa12-13 and pyroxenes are Fs5Wo42-46 and Fs12Wo1. The compositions and texture suggest grouping with the lodranites. However, the metal rich nature of the sample is reminiscent of QUE 93148, which was also originally classified as a lodranite, but may be related to the HEDs or pyroxene pallasites.

Since the time of the original classification, we have obtained oxygen isotope data indicating that this sample is not a lodranite, as originally suggested, but is instead related to QUE 93148. This was also recognized in the original classification notes, and classification as related to QUE 93148 is now favored with the new oxygen data. In addition, the olivine Fe/Mn and Fe/Mg ratios of ~40 and ~0.14, respectively, are also nearly identical to those of olivine in QUE 93148 (Goodrich and Righter, 2000). We thank K. Ziegler for carrying out the oxygen isotope measurements at UNM.

SampleMgdateN
DOM 14289.6 clear1.514-May-181.6823.590-0.2141
DOM 14289.6 clear1.814-May-181.7283.719-0.2361
DOM 14289.6 dark2.714-May-181.9844.184-0.2251

Recommended pairing of LAP 031047 and LAP 03788

As part of an independent study of ordinary chondrites, PI Jon Friedrich carried out a micro CT scan of LAP 03788 and found that it had a nearly identical texture to another LAP chondrite from Wittmann et al. (2011) LAP 031047. Because this texture is unique and these samples were recovered in the same field season we have decided to pair them. Below are the two respective images of slices from the CT scanning (image of LAP 03788 courtesy of J. Friedrich, Fordham Univ., and image of LAP 031047 from Wittmann et al., 2011).

LAP 031047

Wittmann, A., Kring, D. A., Friedrich, J. M., Troiano, J., Macke, R. J., Britt, D. T., Swindle, T. D., Weirich, J. R., Rumble III, D., Lasue, J., 2011, H/L chondrite LaPaz Icefield 031047 – A feather of Icarus?, Geochimica et Cosmochimica Acta, 75, 6140–6159, ISSN 0016–7037, http://dx.doi.org/10.1016/j.gca.2011.07.037 .

LAP 03788
Reclassification and magnetic susceptibility of Dominion Range samples

Magnetic susceptibility of Dominion Range (DOM) 2008 season samples has been measured and presented below, along with suggested reclassification of equilibrated ordinary chondrites, based on the approach presented in AMN 40, no. 1 (Feb. 2017). There we reported that in a study of ~60 samples from Larkman Nunatak and Dominion Range, all H chondrites had log χ
values > 4.9, and no LL chondrites had log χ values > 4.4. We have reclassified ~325 DOM 08 samples using these ranges as well.

SampleWeight (g)AMN Classification New Classification Magnetic SusceptibilityPairing GroupAMN
DOM 080011305.4Euc Brec-3.4733,1
DOM 08002173.22LL (Imp Melt)-3.8633,1
DOM 08003108.98CM2-3.2733,1
DOM 08004294.5CO3-4.89DOM 0800432,2
DOM 0800588.76Euc Brec-3.1632,2
DOM 08006667.3CO3-4.9232,2
DOM 0800724.732H5-4.9933,1
DOM 0800827.07Euc Brec-2.833,1
DOM 0801218.55Ureilite-4.8732,2
DOM 0801328.75CM2-3.87DOM 0801032,2
DOM 0801419.613Euc Brec-2.7132,2
DOM 080171021.1L5-4.8540,1
DOM 080181447.8L6-4.8340,1
DOM 080191434.48L5-4.6340,1
DOM 080201020.6L5-4.8440,1
DOM 080211009.1L5-4.5440,1
DOM 08022825.3LL5L54.8934,1
DOM 08023834.1L6-4.5740,1
DOM 08024912.3LL6L64.7234,2
DOM 08025566.1L6-4.4440,1
DOM 08026222.48LL6L64.6834,1
DOM 08027240.58LL6-3.2934,2
DOM 08028281.72L5H55.134,2
DOM 08029227.02LL5-4.3934,2
DOM 08030255.3L5-4.8834,2
DOM 08031325.9L6-4.6640,1
DOM 08032212.4LL5L54.6234,1
DOM 08033319.7LL5L54.9934,1
DOM 0803496.897L5-4.8734,1
DOM 08035251.4LL6-4.2634,1
DOM 08036153.126LL6L64.5434,2
DOM 08037172.556LL5L54.4934,1
DOM 08038131.332LL6L64.534,1
DOM 0803989.83LL6-4.434,1
DOM 08040106.713LL6L64.6134,1
DOM 08041145.774LL5L54.634,1
DOM 08042125.488LL6L64.5434,1
DOM 0804383.45LL5L54.5734,1
DOM 08044124.432LL6H65.0134,1
DOM 0804582.859LL6-4.3434,1
DOM 08046122.367LL5L54.834,1
DOM 0804778.808LL6L64.6934,1
DOM 0804864.815LL6-4.1934,1
DOM 0804970.331LL5L54.634,1
DOM 08050154.162LL6L64.5534,1
DOM 08051193.111LL5L54.5734,1
DOM 0805288.684LL5L54.4834,1
DOM 0805374.637LL5L54.5834,1
DOM 0805468.21L6-4.8634,1
DOM 0805544.344LL6L64.6534,1
DOM 0805665.944LL6L64.6234,1
DOM 0805744.239L6LL64.3134,1
DOM 0805854.151LL6-4.3634,1
DOM 0805988.031LL6L64.6234,1
DOM 0806049.43LL6L64.6634,2
DOM 0806148.43L5H54.9734,1
DOM 0806251.57LL6L64.6434,1
DOM 0806358.74LL6L64.6934,2
DOM 0806439.29L5H54.9834,1
DOM 0806556.25LL6L64.6234,2
DOM 08066115.57LL5H54.9834,1
DOM 0806728.87LL6L64.6834,2
DOM 0806819.12LL6L64.5434,2
DOM 0806933.98LL6L64.6534,2
DOM 0807035.06LL6L64.734,2
DOM 0807123L6-4.4934,2
DOM 0807228.42LL6L64.6434,2
DOM 0807325.02LL6L64.6634,2
DOM 0807438.7LL6L64.6134,2
DOM 0807520.91LL6L64.5834,2
DOM 0807616.48LL6L64.6834,2
DOM 0807719.43LL6L64.5834,1
DOM 0807816.78LL6L64.7334,2
DOM 0807912.52LL6L64.7134,2
DOM 08080149.856LL5L54.4934,1
DOM 08081193.476LL5L54.5534,1
DOM 08082255.2LL5L54.6334,1
DOM 08083220.108LL6L64.5234,1
DOM 08084247.9L5LL54.1434,1
DOM 0808510.31LL6L64.6234,2
DOM 0808628.77LL5L54.6634,2
DOM 0808738.23LL5H54.9734,1
DOM 0808834.11L5H54.9834,2
DOM 0808953.07LL6L64.7134,1
DOM 0809033.88LL6L64.6834,1
DOM 0809131.76L6H65.0234,2
DOM 0809247.76LL6L64.5834,2
DOM 0809324.37LL5L54.734,2
DOM 0809455.76L5-4.634,2
DOM 0809518L5-4.6434,2
DOM 0809628.07LL6H64.9534,1
DOM 0809756.36LL6L64.6334,1
DOM 0809821.3LL5L54.634,2
DOM 0809921.24L6-4.7134,2
DOM 0810015.36LL6L64.634,2
DOM 0810122.74LL6L64.7134,2
DOM 0810218.86LL6L64.4334,2
DOM 0810314.66LL5H5534,1
DOM 0810428.84LL6L64.5734,1
DOM 0810513.72LL6L64.6234,2
DOM 0810616.24LL6L64.5534,2
DOM 0810716.94LL6L64.7234,2
DOM 0810814.92LL6L64.6534,2
DOM 0810923.28LL5H54.9634,2
DOM 0811085.99L6H65.134,1
DOM 0811136.29L6H64.9534,1
DOM 0811230.793LL6L64.5134,1
DOM 0811358.593LL6L64.4134,1
DOM 0811427.032LL6-4.1234,1
DOM 0811565.307H6-5.0834,1
DOM 0811695.774LL5L54.4834,1
DOM 0811743.898H5-534,1
DOM 08118102.806L5-4.534,1
DOM 0811954.746LL5L54.4834,1
DOM 0812211.32L6H65.1534,2
DOM 0812320.31LL6L64.6934,2
DOM 0812418.19LL6L64.7434,2
DOM 0812520.88L6-4.6234,2
DOM 0812613.52L5H55.3334,2
DOM 0812714.95L5-4.6634,2
DOM 0812818.29LL6L64.634,2
DOM 0812914.24LL6L64.534,2
DOM 0813017.23H5L54.734,2
DOM 0813214.5LL6L64.6134,2
DOM 0813414.86L5H55.1734,2
DOM 0813512.75L5-4.4534,2
DOM 0813618.82H5-5.0934,2
DOM 0813713.69LL6H65.0534,2
DOM 0813921.76CO3-4.82DOM 0800434,2
DOM 0814039.08LL6L64.7134,2
DOM 0814120.35LL6L64.6734,2
DOM 0814221.12L5H55.1434,2
DOM 0814313.94L6H65.1234,2
DOM 0814435.28L5H54.9834,2
DOM 0814520.42L5H55.2634,2
DOM 0814630LL5L54.5734,2
DOM 0814744.11LL6L64.5234,2
DOM 0814833.99LL6L64.7234,2
DOM 0814943.39H6-5.0734,2
DOM 0815012.155LL6L64.6934,2
DOM 0815118.503LL6L64.6834,2
DOM 0815217.008H5L54.5434,2
DOM 0815410.426L5-4.8534,2
DOM 0815522.17LL6L64.5834,2
DOM 0815614.367LL6L64.7434,2
DOM 0815719.071LL6L64.7834,2
DOM 0815913.823L5-4.6334,2
DOM 0816035.594LL6L64.4634,2
DOM 0816118.814LL6-4.2634,2
DOM 0816231.194H4L44.6334,2
DOM 0816319.877L6H65.0834,2
DOM 0816460.688L5H55.1134,2
DOM 0816549.991LL6L64.5234,2
DOM 0816638.158L6H65.0334,2
DOM 0816737.288H5-4.9134,2
DOM 0816820.418L5H55.0734,2
DOM 0816938.486L6H64.9534,2
DOM 0817010.98LL6L64.6334,2
DOM 0817117.35LL6L64.6234,2
DOM 0817238.01H6L64.5934,2
DOM 0817315.35LL6L64.5634,2
DOM 0817428.38LL6L64.6834,2
DOM 0817515.61LL6L64.5534,2
DOM 0817731.03LL6L64.6234,2
DOM 0817822.45LL6L64.7134,2
DOM 0817929.78LL6L64.5634,2
DOM 0818022.74LL5L54.5934,2
DOM 0818135.24LL6L64.5734,2
DOM 0818242.66LL5L54.734,2
DOM 0818328.29L6-4.5434,2
DOM 0818432.79LL6L64.634,2
DOM 0818549.29LL6L64.6734,2
DOM 0818674.41LL6L64.7234,2
DOM 0818727.89LL6L64.6734,2
DOM 0818877.51L6-4.6534,2
DOM 0818930.76LL6L64.6834,2
DOM 0819015.46LL6L64.6134,2
DOM 0819119.23LL6L64.6134,2
DOM 0819223.32LL6L64.6734,2
DOM 0819320.2LL6L64.5434,2
DOM 0819414.35LL6L64.6534,2
DOM 0819540.73LL6L64.5234,2
DOM 0819628.33L6H64.9434,2
DOM 0819722.55LL6L64.6634,2
DOM 0819813.88LL6L64.6834,2
DOM 0819921.62L5H55.1634,2
DOM 0820015.929LL5-4.2634,1
DOM 0820121.108LL5L54.6734,1
DOM 0820221.75L5-4.6434,1
DOM 0820333.172LL5-4.1334,1
DOM 0820424.069LL6L64.4934,1
DOM 0820517.656LL6L64.4934,1
DOM 0820638.973LL6L64.5834,1
DOM 0820722.579LL6L64.8834,1
DOM 0820827.053LL6L64.634,1
DOM 0820925.418L6-4.6334,1
DOM 0821015.943LL6L64.4234,1
DOM 0821112.62LL6L64.6334,1
DOM 0821514.553LL6L64.5334,1
DOM 0821613.031L6-4.6134,1
DOM 0821713.35LL6L64.834,1
DOM 0821818.343L6-4.7634,1
DOM 0821921.854LL6H64.9434,1
DOM 0822141.19LL6L64.6834,2
DOM 0822216.64LL6L64.6334,2
DOM 0822321.31LL6L64.6334,2
DOM 0822431.56L6-4.6734,2
DOM 0822521.69LL6L64.6534,2
DOM 0822621.22LL6L64.6734,2
DOM 0822720.36L6-4.6934,2
DOM 0822818.07LL6L64.6534,2
DOM 0822911.24LL6L64.6434,2
DOM 0823029.612LL6L64.5334,1
DOM 0823123.262LL6L64.5634,1
DOM 0823220.378LL6L64.7134,1
DOM 0823318.884LL6L64.7134,1
DOM 0823437.491LL5L64.5534,1
DOM 0823525.801LL6L64.6734,1
DOM 0823627.559H6-4.9534,1
DOM 0823731.324LL6L64.5634,1
DOM 0823829.901LL6L64.6334,1
DOM 0823924.191H5-5.1534,1
DOM 0824037.443LL6-4.434,1
DOM 0824120.557LL6-4.2234,1
DOM 0824225.113H6L64.5834,1
DOM 0824343.244LL6L64.4534,1
DOM 0824445.384LL6L64.4434,1
DOM 0824542.2LL6L64.4534,1
DOM 0824642.321LL6-4.3434,1
DOM 0824761.735LL6L64.5534,1
DOM 0824832.946LL6-4.3334,1
DOM 0824972.204LL5L54.7634,1
DOM 0825022.93L6-4.6634,2
DOM 0825120.01LL6L64.6534,2
DOM 0825228.77LL6L64.6634,2
DOM 0825337.88LL6L64.6934,2
DOM 0825425.51LL6L64.6834,2
DOM 0825529.29LL6L64.6834,2
DOM 0825678.46LL5-4.1734,2
DOM 0825719.78L5-4.6734,2
DOM 0825848.39LL6-4.3534,2
DOM 0825964.17LL6L64.7134,2
DOM 0826122.61L6-4.6634,2
DOM 0826215.01LL6L64.6634,2
DOM 0826312.43L5H55.0334,2
DOM 0826630.06LL6L64.5634,2
DOM 0826719.84LL6L64.6434,2
DOM 0826830LL6L64.7334,2
DOM 0826929.32LL6L64.5534,2
DOM 0827029.52LL6L64.5134,2
DOM 0827164.99L6H64.9834,2
DOM 0827252.67LL6-4.1634,2
DOM 0827356.6LL6L64.7734,2
DOM 0827433.15LL6L64.6334,2
DOM 0827560.9LL6L64.6534,2
DOM 0827636.8LL6L64.6634,2
DOM 0827721.04LL6L64.5934,2
DOM 0827883.61LL6L64.7834,2
DOM 0827930.85LL6L64.4634,2
DOM 0828023.97L6-4.5634,2
DOM 0828115.32LL6L64.5634,2
DOM 0828220.81LL6L64.6134,2
DOM 0828525.02LL6L64.5234,2
DOM 0828712.6LL6L64.6834,2
DOM 0828813.99L6LL64.3134,2
DOM 0829024.82LL6L64.7834,2
DOM 0829128.72LL6L64.4834,2
DOM 0829229.17LL5L54.6334,2
DOM 0829320.82LL6L64.6834,2
DOM 0829428.71L6-4.8234,2
DOM 0829528.51H5L54.7634,2
DOM 0829623.7L6H65.1934,2
DOM 0829757.09LL6L64.6934,2
DOM 0829823.92LL6L64.6134,2
DOM 0829922.16LL6L64.634,2
DOM 0830215.61L6-4.6634,2
DOM 0830311.12L6-4.7834,2
DOM 0830613.29L6-4.5834,1
DOM 0831212.87LL6L64.634,1
DOM 0831318.52L5H54.9134,2
DOM 0831412.89L6H64.9134,2
DOM 0831620.34LL6L64.6534,1
DOM 0831728.17L6H65.0234,2
DOM 0831919.16LL6L64.734,1
DOM 0832114.1LL6L64.634,1
DOM 0832315.87L5H54.9634,2
DOM 0832412.41LL6L64.5434,2
DOM 0832518.85LL6-3.9834,1
DOM 0832619.12LL6L64.734,1
DOM 0832819.54LL6L64.5734,1
DOM 0833018.04L6-4.6433,2
DOM 0833121.01H6L64.8933,2
DOM 0833224.03L6-4.5633,2
DOM 0833335.64LL6L64.6133,2
DOM 0833419.76LL6-3.5734,1
DOM 0833530.58L6-4.7234,1
DOM 0833626.11LL6L64.7833,2
DOM 0833727.62L (Imp Melt)-4.6DOM 0839734,1
DOM 0833818.98L6-4.833,2
DOM 0833934.84LL6L64.6533,2
DOM 0834411.38L6H65.1434,1
DOM 0834710.32L6H65.1734,1
DOM 0835126.3CO3-4.88DOM 0800434,1
DOM 0835214.63H6LL64.233,2
DOM 0835312.68L5-4.6534,1
DOM 0835610.96LL6L64.6233,2
DOM 0835921.35LL6L64.5233,2
DOM 0836014.61L6LL64.3534,2
DOM 0836138.72LL6L64.5334,2
DOM 0836219.78LL6L64.5534,2
DOM 0836324.29LL6L64.6734,2
DOM 0836420.95LL5L54.7334,2
DOM 0836518.97L6-4.8634,2
DOM 0836648.73L6H65.134,2
DOM 0836720.93H6-5.2834,2
DOM 0836828.45LL6L64.634,2
DOM 0836918.04LL6L64.6234,2
DOM 0839083.27H5-5.134,1
DOM 0839180.62H6LL64.1133,2
DOM 0839279.1L6-4.5534,1
DOM 0839334.17LL6L64.6833,2
DOM 0839442.43LL6L64.5833,2
DOM 0839553.21LL6L64.4433,2
DOM 0839644.79LL5L54.7633,2
DOM 0839768.77L (Imp Melt)LL (Imp Melt)4.3534,1
DOM 0839859.71LL5L54.5533,2
DOM 0839985.5L6-4.6633,2
DOM 0840049.91L6H64.9434,2
DOM 0840197.86L5H54.9334,2
DOM 0840255.75L5H55.0834,2
DOM 0840378.67L5-4.8934,2
DOM 0840470.27L6H65.0234,2
DOM 0840592.8L5H55.1334,2
DOM 0840645.88L5H55.0434,2
DOM 08407115.61L6H65.0934,2
DOM 0840871.32LL6L64.7734,2
DOM 0840976.49LL5-4.3434,2
DOM 0841029.34L6H65.2234,2
DOM 0841147.38LL5L54.6533,2
DOM 0841237.65LL5L54.7433,2
DOM 0841332.52LL5L54.5833,2
DOM 0841441.98H6-5.1533,2
DOM 0841541.96L6-4.4833,2
DOM 0841682.04LL5L54.6633,2
DOM 0841731.52L6-4.6433,2
DOM 0841829.61L6-4.6533,2
DOM 0841992.95L5-4.6233,2
DOM 0842054.75LL6L64.5634,2
DOM 0842149.06LL6L64.6634,2
DOM 0842217.85LL6L64.634,2
DOM 0842324.93LL5L54.7834,2
DOM 0842453.09LL6L64.734,2
DOM 0842531.41LL6L64.6134,2
DOM 0842624.78LL6L64.5934,2
DOM 0842745.01LL6L64.5834,2
DOM 0842819.72LL6L64.6434,2
DOM 0842923.27LL6L64.5234,2
DOM 08430108.68LL5L54.7133,2
DOM 08431128.92LL6L64.733,2
DOM 0843259.78LL5L54.6933,2
DOM 0843365.88LL5L54.6533,2
DOM 0843485.58LL6L64.833,2
DOM 0843560.46H6-4.9133,2
DOM 08436147.27LL5-3.8533,2
DOM 0843745.47LL6L64.6133,2
DOM 08438113.07LL6L64.7633,2
DOM 08439106.19LL6L64.6833,2
DOM 0844029.7L5-4.6834,1
DOM 0844112.74L6-4.6734,1
DOM 0844214.23H5L54.6634,1
DOM 0844320.12L5H55.0534,1
DOM 0844436.75L5-4.634,1
DOM 0844512.33L6-4.5534,1
DOM 0844625.81L5-4.6434,1
DOM 0844718.61L6-4.6134,1
DOM 0844857.63LL5L54.6634,1
DOM 0844940.54LL6L64.6234,1
DOM 0845020.41LL5L54.7234,1
DOM 0845111.59L6-4.6334,1
DOM 0845314.89L6-4.7434,1
DOM 0845430.43LL5L54.6134,1
DOM 0845518.98H6-5.134,1
DOM 0845610.71H6L64.6234,1
DOM 0845716.95LL6L64.7334,1
DOM 0845819.2LL6L64.7134,1
DOM 0845921.27LL6L64.6134,1
DOM 0846053.41LL5L54.6834,1
DOM 08461122.41L6H64.9734,1
DOM 08462133.88LL5L54.5734,1
DOM 08463160.89LL5H54.9234,1
DOM 0846472.6L6H64.9834,1
DOM 0846592.5L6H65.0634,1
DOM 0846648.68LL5L54.6534,1
DOM 0846782.49LL5L54.5734,1
DOM 0846864.81H3.5L3.54.5534,1
DOM 08469148.79LL5L54.6934,1
DOM 0847036.313LL6L64.6234,1
DOM 0847131.255LL6L64.6634,1
DOM 0847218.503LL5L54.5634,1
DOM 0847314.869LL5L54.5734,1
DOM 0847417.445LL6L64.5334,1
DOM 0847517.927L5-4.4834,1
DOM 0847625.079CV3-3.5934,1
DOM 0847714.539LL5L54.734,1
DOM 0847821.157LL5L54.5934,1
DOM 0847911.899L6-4.5634,1
DOM 0848014.45H5L54.6734,1
DOM 0848221.4LL6L64.534,1
DOM 0848319.2L6-4.6334,1
DOM 0848422.37LL6L64.6634,1
DOM 0848518.31LL6L64.5434,1
DOM 0848623.04LL6L64.5334,1
DOM 0848725.21LL6L64.5734,1
DOM 0848825.21LL6L64.6534,1
DOM 0848912.89LL5L54.6734,1
DOM 0849018.54LL6L64.4634,1
DOM 0849134.47L5-4.6334,1
DOM 0849235.65LL6L64.4634,1
DOM 0849322.76LL5L54.5934,1
DOM 0849421.19L6H65.0134,1
DOM 0849538.06H6-4.9634,1
DOM 0849615.53L6H65.0334,1
DOM 0849728.72L6-4.4734,1
DOM 0849816.91LL6L64.4934,1
DOM 0849955.38LL6L64.634,1
DOM 0850065.836LL6L64.5934,1
DOM 0850168.736LL5H55.0434,1
DOM 0850268.757LL6L64.5634,1
DOM 0850315.281LL6-4.0134,1
DOM 0850451.177LL6L64.4734,1
DOM 0850542.396L6-4.5734,1
DOM 0850648.88LL6-4.1634,1
DOM 0850737.465LL6-4.3234,1
DOM 0850828.471L6-4.5434,1
DOM 0850929.255H5L54.6434,1
DOM 08510166.495LL6-4.0933,2
DOM 08511124.851LL6-3.5433,2
DOM 08512208.315LL5-4.3733,2
DOM 08513102.151LL5L54.6933,2
DOM 0851467.101LL6L64.7833,2
DOM 0851516.188LL6L64.7134,1
DOM 0851621.981LL6L64.5234,1
DOM 0851728.403LL6L64.5534,1
DOM 0851818.932LL6L64.7134,1
DOM 0851922.642H6L64.8934,1
DOM 0852031.077LL6L64.5634,1
DOM 0852115.972LL6L64.4834,1

Field plan for the 2018-19 ANSMET Field Season

Ralph Harvey, Case Western Reserve University
Jim Karner, University of Utah

We’re sure most readers of this newsletter can appreciate how much planning is involved to get a typical ANSMET season underway. In many cases it can be several years between the time an icefield is targeted in a support proposal to the day that ANSMET boots first set foot on the ice. Usually the six months before a season is when the pace really picks up. Details of the needs of the field party matched to the logistical capabilities of the US Antarctic program, with several rounds of feedback gradually turning plans into achievable reality. There are other cases where logistical issues (ranging from broken airplanes to a broken US Congress) can force planning to start all over from square one with no more than a day or two’s notice. Somehow, (due to either luck, or deep forward thinking, or both) ANSMET has managed to field a team in every austral summer except one since 1976.

That's worth mentioning because for reasons too complicated to be discussed here, detailed planning for the upcoming 2018–19 season is not yet complete. Obviously we’d like everything to be set in stone, but we’re no strangers to uncertainty. So we’ll just keep pushing things as far forward as we can. Currently we plan a return to the icefields surrounding the Davis Nunataks and Mt. Ward, not surprisingly known as "Davis–Ward". Meteorites (designated DOM for the nearby Dominion Range) were first found at this site during a reconnaissance traverse through the upper Beardmore region by Bill Cassidy in 1985. In the 2003–04 season, a recon team visited the area for five days and recovered 89 meteorites, which pointed to the need for a systematic search of the area. Systematic searches in the 2008–09, 2010–11, and 2014–15 seasons yielded another 2000 meteorites. The Davis–Ward area is essentially a broad tongue of ice between two isolated mountains, which are joined by a recessional moraine (Figure 1). Meteorites have been recovered from all parts of the bare ice, but most have been found in either the 100–meter–wide trough that runs along the foot of Mt. Ward, or the moraines that outline the "mitten" (see Fig. 1). The bare ice is often heavy with terrestrial rock, so systematic sweeping can be slow-going. This year our goal is to complete search and recovery work at Davis–Ward; systematically search bare ice where it is warranted and methodically work through what remains of the unsearched moraines surrounding the icefields. If we finish early (and that’s a big if), we will make a snowmobile traverse about 20 nm north to the Main Icefield at the foot of the Dominion Range. The team would spend the rest of the season on search and recovery efforts from the icefields there.

Composite satellite image of the Davis-Ward icefields

Figure 1. Composite satellite image of the Davis–Ward icefields, with Mt. Ward to the right and Davis Nunataks to the left. The image is oriented with north toward the top. The remaining unsearched areas are about "half the fingers" and "part of the thumb" of the mitten-shaped central icefield.

Report from the Smithsonian

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

Things are rolling along as usual at the Smithsonian. The Hyperprobe is still running beautifully and the SEM is back online, allowing us to use both for classification of Antarctic meteorites. We have secured the funding for two, one-year positions in the Division of Meteorites, and are looking forward to having those folks on board sometime later this fall. We have ordered new cabinets for our meteorite vault in the Museum on the Mall, which will expand our storage capability, provide more workspace and a new display case. Finally, we are very sorry to see our current post doc, Nicole Lunning, move on to the next steps in her career this fall. Nicole has been an amazing asset to our department and she will be missed.