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Getting between rocks in a small place

Thermal Ionization Mass Spectrometry facility will boost geoscience at BU

Ethan Baxter (right), a CAS assistant professor of earth sciences, teaches a class at an outcrop of Roxbury puddingstone in Boston's Harris Park. Photo by Arancha Pinan (GRS'06)

The College of Arts and Sciences department of earth sciences was recently awarded a $600,000 grant from the National Science Foundation (NSF) to establish a thermal ionization mass spectrometry (TIMS) facility.

Under the directorship of Ethan Baxter, a CAS assistant professor of earth sciences, the TIMS facility will give the members of the department and other users the capability to measure isotope ratios of elements such as strontium, neodymium, calcium, and lead, with extremely high precision on a wide variety of geological samples.

“One of the main focuses of my work — and the work of the three other principal investigators of the grant — is to push the limits on analyzing very small samples,” Baxter says. “The TIMS facility will give us more precise information on past geologic events.”

Mass spectrometry is a technique for separating ions by their mass-to-charge ratios. It allows the detection of compounds by separating ions by their unique mass. It helps scientists identify compounds by the mass of one or more elements in a compound or determine the isotopic composition of one or more elements in a compound.

According to Baxter, the TIMS facility, which includes a MicroMill sampling device to collect tiny samples, will also benefit a wide spectrum of graduate and undergraduate researchers, at BU and at other institutions. “We have colleagues, in the biology department in particular,” he says, “who have expressed interest in using TIMS instrumentation.”

Mass spectrometry is widely used in biomedical science. In 1994, Catherine Costello research professor of biochemistry and biophysics at MED, established the Mass Spectrometry Resource, one of several spectrometry programs on the Medical Campus now affiliated with the Center for Biomedical Mass Spectrometry.

The new CAS facility will aid geoscience research in igneous and metamorphic petrology, weathering and surface processes, oceanography, and paleoclimate, which are all strengths of the four principal investigators in the earth sciences department: Baxter, Assistant Professor Andrew Kurtz, and Professors Richard Murray and Terry Plank.

Baxter is interested in applications of geochemistry, geochronology, and petrology to understand and quantify the rates and timescales of geological processes affecting the evolution of Earth’s crust and mantle. “I study the rates of mountain-building processes and the reactions that are happening deep in the roots mountain-forming systems,” he says.

The department expects the facility to be operational by next summer and will hire a full-time technician — supported by BU and NSF funds. Those interested should call Baxter at 617-358-2844 or e-mail him at efb@bu.edu.