Prism and Optima Transducer - Carbonate calibration

Industrious graduate student users of the stable isotope laboratory (Steve Bohaty and Brandon Murphy) have dilligently weighed out Carrera Marble and NBS-19 standards over time to calibrate the autocarbonate device pressure transducer to calcium carbonate mass. With this calibration combined high quality isotopic (oxygen and carbon) records and percent calcium carbonate records from bulk carbonate samples can be generated. Below are the calibrations that have been established linking the pressure transducer reading to the amount of calcium carbonate digested in the common acid bath of the autocarbonate device.

Prism Transducer - Carbonate Calibration

The Prism autocarbonate device pressure transducer displays an odd behavior in that it will sometimes read positive and sometimes negative readings when measuring the amount of calcium carbonate generated. When working with unknowns, estimates of percent calcium carbonate are made using one of two different calibrations. If the transducer yields positive values, use the "positive" calibration, and a negative transducer dictates that the "negative" calibration is used.

Optima Transducer - Carbonate Calibration

Carbonate Mass (µg) = 25.918 * Transducer Reading + 21.672

The Optima autocarbonate pressure transducer displays a very high correlation to carbonate mass. Many very nice %CaCO₃ records have been generated simultaneously with δ¹⁸ and δ¹³C records using this calibration.

NEWS & EVENTS

November 2009

UCSC's SIL retires its 15 year-old dual-inlet Optima following a very productive career that generated over 40,000 data points.

November 2009

Two Tsavo Lions In Famed Killings Get Partial Reprieve according to UCSC Graduate Student Justin Yeakel as inteviewed on NPR's All Things Considered. Listen here:

July-August 2009

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.

December 2008

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".

September 2008:

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.

July 2008:

SIL co-director Jim Zachos (Earth and Planetary Sciences) recieves prestigious Humbolt Research Award. See Humbolt Award for details.

May 19, 2006: UCSC Stable Isotope Laboratory Symposium

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.