Week 1 Recap

I intend to use this blog to post summaries of what I've done each week as a sort of progress report.

I selected seven corals from bagged samples in Mitchell cold storage and moved them to Green 044 for cleaning. These were rinsed in DI water, sonicated in DI water for 10 minutes, rinsed in DI water, sonicated in ethanol for 3 minutes, rinsed in DI water, and finally sonicated in DI water for 15 minutes. I photographed these corals using the reflected light microscope in 320-222. These photographs will be an important record after the corals are dissolved for analysis. During photography I noticed that corals 1419A and 1420 were in need of further cleaning.

I also removed small samples of the mud, sand, or shell hash from all bagged samples. I viewed these under the reflected light microscope but was not able to take useful photographs because I am not familiar enough with foraminifera.

Simon and I met with Dave Mucciarone and Sverre LeRoy to discuss radiocarbon dating. I went with Sverre to the USGS core lab in Menlo Park, and she showed me their core splitter.

We agreed to postpone the next step in U/Th dating (sample dissolution) until we had determined whether radiocarbon dates at LLNL could be used to determine which corals were older than the LGM. We have not yet discussed in detail which samples will be sent to LLNL, nor have we discussed the timeline for dating mollusk shells (whether this will be done after corals or concurrently).

I read and took notes on the following papers:

Bischoff, J.L., and Fitzpatrick, J.A., 1991, U-series dating of impure carbonates: An isochron technique using total-sample dissolution: Geochimica et Cosmochimica Acta, v. 55, p. 543–554.

Luo, S., and Ku, T.L., 1991, U-series isochron dating: A generalized method employing total-sample dissolution: Geochimica et Cosmochimica Acta, v. 55, p. 555–564.

Ludwig, K., and Titterington, D., 1994, Calculation of 230-Th/U isochrons, ages, and errors: Geochimica et Cosmochimica Acta, v. 58, p. 5031–5042.