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Useful references for calcium carbonate samplesIAEA Isotope Hydrology Laboratory PublicationsIAEA Isotope Hydrology Laboratory Publications δ18O based paleotemperature equation from carbonates.Dual-Inlet Source Mixing Characterization.Meijer et al., Cross contamination in dual inlet isotope ratio mass spectrometers, International Journal of Mass Spectrometery, 198, 45-61, 2000. McCrea, J. M., On the Isotopic Chemistry of Carbonates and a Paleotemperature Scale, J. Chem. Phys. 18, 849 (1950); doi:10.1063/1.1747785 Tyler B. Coplen, Carol Kendall & Jessica Hopple, Comparison of stable isotope reference samples, Nature 302, 236 - 238 (17 March 1983); doi:10.1038/302236a0 17O correction.Kaiser, J., Reformulated 17O correction of mass spectrometric stable isotope measurements in carbon dioxide and a critical apraisal of histroic 'absolute' carbon and oxygen isotope ratios, Geochimica et Cosmochimica Acta, 72, 1312-1334 (2008) Brand, W., Assonov, S. & Tyler B. Coplen, Correction for the 17O interference in δ(13C) measurements when analyzing CO2 with stable isotope mass spectrometry (IUPAC Technical Report), Pure and Applied Chemistry, 82, 8, 1719-1733 (2010) Aragonite Notes:For those of you running aragonite for d18O using phosphoric acid digestion: raise your hand if you take into account the different acid fractionation of aragonite relative to calcite as in Kim et al. 2007. Kim S-T, Mucci A, Taylor BE. 2007. Phosphoric acid fractionation factors for calcite and aragonite between 25 and 75 *C: revisited. Chemical Geology 246: 135-146. If you run the kiel at 70*C, your aragonites would be 0.3772 permil heavier. Thank you. Andrew Schauer Dolomite proceduresThe selective acid extraction method of Al-Aam et al. (1990). has been commonly used to distinguish the C and O isotopic composition of different carbonate components that are composed of the mixture of calcite and dolomite. The mixture powder (~50 mg) was reacted in three steps: (1) with >100% H3PO4 at 25°C for 2 h in vacuum to extract CO2 from the calcite fraction, (2) continuously with >100% H3PO4 at 25°C for 24 h in vacuum to extract CO2 from the calcite-dolomite mixture, (3) the remaining material was reacted at 50°C for more than 100 h to obtain CO2 from the dolomite. A further discussion on this method was presented by Yui and Gong (2003). Al-Aasm, I.S., Taylor, B.E., South, B., 1990. Stable isotope analysis of multiple carbonate samples using selective acid extraction. Chem. Geol. 80, 119-125. Yui, T.-F. and Gong, S.-Y., 2003. Stoichiometry effect on stable isotope analysis of dolomite. Chem. Geol. 201, 359-368. Apatite proceduresThere has been a discuss on this among apatite dissolvers recently. It is very important to heat, under vacuum for at least an hour, to remove water and then to load the samples immediately for the run. Ross Secord at Nebraska heats to as high as 200°C (). Most everyone else heats to 65-80°C. DO NOT heat at very high T (>200°C). You will begin to lose carbonate. I think 200°C is a little risky, but Ross has a specific scientific question that justifies higher temperatures. Kiel Carbonate Device and MAT 253 Manuals and Brochures.Kiel IV Carbonate Device Manual Kiel IV Carbonate Device Brochure |
 NEWS & EVENTSDiversity of great white shark diet was shown to be greater than previously thought based on research by UC Santa Cruz colleagues Sora Kim, Paul Koch, and James Estes along with co-autor M. Tim Tinker of the U.S. Geological Survey. This work was highlighted in the Los Angeles Times. SIL Co-Director Paul Koch has been named Dean of the UC Santa Cruz Division of Physical and Biological Sciences. Madagascar Lemur extinctions and ecological retreat followed arrival of humans according to UCSC Graduate Student Brooke Crowley, Professor Paul Koch and co-authors. Their findings were recenlty published in the journal Proceedings of the Royal Society B. SIL Co-Director Paul Koch was quoted in the New York Times on research showing that a tiny Paleocene horse Sifrhippus, the first horse, grew even smaller during the Paleocene-Eocene Thermal Maximum climatic warming event. SIL Co-Director Christina Ravelo has been selected as an American Geophysical Union (AGU) Fellow. SIL Co-Directors Paul Koch and Jim Zachos's research on Paleocene-Eocene Thermal Maximum (PETM) climatic warming event is featured in an National Geographic article "Earth Before the Ice" in the October 2011 issue. SIL Co-Director Paul Koch has been appointed Interim Dean of the UC Santa Cruz Division of Physical and Biological Sciences. SIL Co-Director Jim Zachos elected to the American Academy of Arts and Sciences. UCSC's SIL new ThermoScientific MAT 253 isotope ratio mass spectrometer coupled to a Kiel Automated Carbonate Device begins regular operations. UCSC's SIL retires its 15 year-old dual-inlet Optima following a very productive career. The instrument generated over 40,000 data points. Two Tsavo Lions In Famed Killings Get Partial Reprieve according to UCSC Graduate Student Justin Yeakel. Listen to Justin's inteview on National Public Radio's All Things Considered: SIL co-director Christina Ravelo (Ocean Sciences) sails as co-chief scientist on Integrated Ocean Drilling Project (IODP) Expedition 323 to investigate Bearing Sea Paleoceanography.
SIL co-director Christina Ravelo (Ocean Sciences) gives the 2008 Emiliani Lecture at the American Geophysical Union Meeting in San Francisco on "Lessons from the Pliocene Warm Period and the Onset of Northern Hemisphere Glaciation".
UCSC SIL has been funded by the National Science Foundation for a new Dual-Inlet Isotope Ratio Mass Spectrometer with individual acid drip system for very small calcium carbonate samples. SIL co-director Jim Zachos (Earth and Planetary Sciences) recieves prestigious Humbolt Research Award. See Humbolt Award for details. SIL Co-Director Jim Zachos has been selected as an American Geophysical Union (AGU) Fellow. In recognition of the new continuous flow instruments added to the UCSC stable isotope facility a Symposium is being run to highlight the new analytical capabilities. |
