Ice is Gneiss….

I passed a very enjoyable time this night listening to the technical briefing that Christine Siddoway (Geology, Colorado College) gave her field team members, who will be heading out to the Fosdick Mountains of Western Antarctica. The Fosdicks, based on furtive notes I made during her overview, are the ramparts of a Cretaceous dome of migmatite — forgive me if I can’t be more technical, but on my map they are very very tiny, and resemble the double-v’d feather of an arrow, or a poorly fossilized crustacean, or the dried imprint of mud that might fall from the tread of your hiking boots. Christine spoke passionately about plutonic forces, “heavily folded fabrics” (bedding lines and deformation) and their distant connection to the Western Antarctic Rift. (As the bumper-sticker says: “Reunite Gondwanaland!”). Their project (STAMP: Structure Tectonics and Metamorphic Petrology – the Gneiss Dome Architecture) was not on my initial field plan, but Thomas Wagner, the NSF Science Rep, realized it would be a (rare) opportunity for me to see this section of Antarctica!

They are finalizing their “put-in” site, for a safe landing and field camp for the season, which will probably be on a snow dome just south of the mountains. I hope the flight isn’t cancelled. Technically, I will be seeing it all from the side portal window of our airplane, since this is just a recon flight, but I’ve had some spectacular views this way, already. Not sure what I’ll be able to see from the air… hopefully we’ll circle a bit. For those of you playing along from home, here are the approximate map coordinates of their preferred location:

-76° 33.24′
-145° 29.03′

Along the way, we could have some excellent views of the Ice Shelf, where it meets the open ocean, including the shear zone where the shelf gave birth to that famous iceberg, B-15. Doug MacAyeal showed me a few satellite images of the area, and a major crack they are watching (could a twin for B-15 be waiting?).

If all goes well, I will head out to visit Sam Bowser’s diving group (Foraminifera) midweek. Henry, the artist & diver working with Sam, just sent me this amazing underwater picture!

Image by Henry Kaiser: New Harbor – from below the surface!

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