Kevin Righter, NASA-JSC
This newsletter reports 498 new meteorites from the 2007, 2008, and 2009 ANSMET seasons from the Miller Range (MIL) and the Dominion Range (DOM). These new samples include one acapulcoite/lodranite, three ureilites, three CB chondrites, two CM1, two CM1/2, 37 CO3 (36 paired with MIL 07099), one CR3, nine CV3 (8 paired with MIL 07590), one H3.5, five enstatite chondrites, two R chondrites, five L chondrite impact melts, and one tiny mesosiderite. The publication of this newsletter completes the classification of the 2007 season meteorites.
The meteorite collection received 74 requests for the Fall MWG meeting, and although all of the sample chips have been prepared and sent out, there are a number of thin sections that still need to be completed. Thank you for your patience in getting all of the new sections made — we had close to 150 new sections and all could not be prepared before the end of 2010.
Numbering scheme for ALH 09 meteorites
In the Fall 2010 newsletter we announced a new howardite, ALH 090004. The Meteorite Nomenclature Committee has asked us to remove the 6th digit in the ALH 09 series (a total of eleven meteorites from 2009-2010 ANSMET season). Therefore, the new number of this sample is ALH 09004, and all future announcements for ALH samples from 09 series will be 09001 to 09011.
Meteorites recovered from blue ice
We neglected to include some important information about two samples announced in last newsletter — volume 33, number 2. MIL 07710, a 147.13 g L4 chondrite, appeared in Table 1 without a detailed description. However, it was one of a very small number of ANSMET samples that has been recovered from blue ice. In February 2008 (AMN volume 31, number 2) a call went out to PIs interested in studying the ice and meteorite together. Also announced last year was a second sample recovered in ice by the ANSMET field team — MIL 091010, a 51.66 g CV3 chondrite that is paired with three other Miller Range CV3s. In response to the call for coordinated ice and meteorite studies from the Feb. 2008 newsletter, these two samples were taken to the CRREL labs in New Hampshire so that the samples could be carefully cut out of the ice and pieces of ice removed and subdivided for several PIs. The meteorites were then returned to JSC still frozen since their collection in the blue ice) and thawed in the JSC meteorite processing lab in the same procedure used for all of our meteorites. We have added some additional description text to the original descriptions posted on our webpage. Also below are a few photos of these samples.
MIL 091010 in Ice Block
Closeup of MIL 091010 in Ice
Processing Photo of MIL 091010
MIL 07710 Encased in Ice
MIL 07710 Protruding From Ice After Cut
Processing Photo of MIL 07710
Report from the Smithsonian
Cari Corrigan, Geologist (Dept. of Mineral Sci.)
This newsletter announces the classification of 507 rocks (498 meteorites and 9 terrestrial rocks) and closes out the classification of the Miller Range (MIL) '07 season! We are continuing to work on the Dominion Range '08 season (~ 50% complete) and the MIL '09's. The Smithsonian currently has two post doctoral fellows (Karen Stockstill-Cahill and Yulia Goreva) and a contractor who joined us since the last newsletter (Nicole Lunning, MSc, UC Davis, 2009) who have helped make this newsletter the largest in a long time. Dr. Emma Bullock will be joining the museum as a Trust Employee (conversion from Postdoctoral Fellow) and will help in the Antarctic crusade, as well. Thanks go out to Dr. Jeff Grossman for supporting the Antarctic Meteorite classification efforts at the Smithsonian through a NASA Curation Program. On another curation note, our new meteorite facility at our offsite Support Center is almost complete and should allow us to comfortably house incoming Antarctic meteorites through another 20 seasons or so!
2010-2011 ANSMET Field Season Report
Ralph Harvey, Principal Investigator, ANSMET
The 2010-2011 ANSMET expedition was one of our most active and involved field seasons, with two main parties and three sub-parties deploying to over a half dozen different locations. Our larger field party deployed to the icefields surrounding the Davis Nunataks and Mt. Ward of the Dominion Range of the Transantarctic Mountains, more commonly known as the Davis-Ward icefields.
Systematic Team: (back row) Inge Tenkate, Rhiannon Mayne, Shaun Norman, Bill Satterwhite, Ray Jayawardhana; (kneeling) Ryan Zeigler, Jim Kamer, Ralph Harvey
Joe Boesenberg, Ryan Zeigler, Bill Satterwhite (Penguin beanies made by Rhiannon Mayne)
The team included myself, Jim Karner, Shaun Norman, Joe Boesenberg, Rhiannon Mayne, Inge Loes Ten Kate, Ryan Zeigler, Ray Jayawardhana and Bill Satterwhite and was able to conduct systematic searches almost every day, in weather that was sometimes uncomfortable but rarely cruel. Many of the 901 meteorites recovered came from areas with abundant dark fine-grained terrestrial rock, keeping the team on its toes and promising a higher-than-usual rate of false positives.
At mid-season I was joined by Karen Hilton from Field Safety and Training Operations in McMurdo, for a three day exploration of the icefields surrounding Mt Darwin in the Buckley Island Region (near the top of the Beardmore Glacier). We recovered 30 specimens and left behind a concentration worthy of a visit by a larger team in the future. Jim Karner and Joe Boesenberg made a similar reconnaissance visit to some icefields near Moody nunatak at the end of the season, but had no luck finding meteorites. They did, however, recover data and sensors left behind at the Miller Range last year.
Recon Team: John Schutt, Serena Anoun, Melissa Lane and Stephen Ballou
ANSMET also did some travelling much further afield. Before the fieldwork began, John Schutt and I travelled to South Pole Station where we boarded a Basler turboprop for a very long overflight of potential reconnaissance targets. We had a good look at a number of icefields in and around the Argentina Range, Omega Nunatak and Whichaway Nunataks, as well as a number of previously un-named and unnoticed nunataks along the way. Many of these sites look very promising; but unfortunately their distance from normal US logistical hubs and a surfeit of landing sites will pose challenges for future visits.
Our four person reconnaissance team (John, Serena Aunon, Melissa Lane and Stephen Ballou) deployed to some previously-unvisited icefields at the far eastern end of the LaPaz region a few weeks later, recovering a nice collection including some impressively big specimens. At mid-season the team moved to the main icefield of the Patuxent Range, an area visited only briefly 20 years ago. Here too they were successful, bringing the total recovered by the reconnaissance team to 302. In summary, a challenging season resulted in some significant rewards including over 1200 new specimens and several new icefields to explore.
Systematic Team: (standing) Ryan Zeigler, Ralph Harvey, Inge Tenkate; (seating) Ray Jayawardhana, Jim Kamer, Rhiannon Mayne, Bill Satterwhite; (on ice) Shaun Norman