29 May 2012
The final meeting of my spring semester Snowball Earth class was a field trip to the University of Maryland, hosted by Snowball guru Jay Kaufman, a specialist in chemostratigraphy using stable isotopes.
Here, Jay welcomes the class to his wet lab:
Doing chemostratigraphy takes lots of samples.
Here’s a drawer full of samples from one of Jay’s many field areas:
Then it was time for show and tell. Jay brought out some of his most charismatic Archean and Proterozoic samples. Here, for instance, is a BIF with tiger’s eye:
We made a macro GigaPan of this sample here.
Next up, some “tubestone” stromatolites that lived in the hothouse aftermath of the Snowball Earth glaciation. The idea is that these guys exist in the “cap carbonate” layer in such a distinctive morphology because they were being “buried alive” by the massive, rapid precipitation of calcite from the ocean.
A closer look:
Here are two samples that show trace fossils from Precambrian organisms…
Have you heard of the Ediacaran fauna? Here’s half a Dickinsonia:
Other Ediacaran body fossils – sort of blob shaped:
Giant ooids from the Beck Springs Formation of Death Valley, California:
Another Beck Springs sample, where the ooids have been cross-sectioned:
We made a macro GigaPan of this one, too. Here’s the opposite side, all sawed, ground down, and polished up:
Finally, Jay took us upstairs to the mass spectrometer, and discussed its use and care:
Everyone had a good time, and they claimed to have learned a lot on the trip. One of my most experienced students said it was one of her top five geology field trips of all time, so I think that says a lot about the level of interest in the facilities, samples, and general “feel” the NOVA students got visiting a big research university.
Thanks for showing us a good time, Jay!