Dear All,
The Department of Earth and Environmental Sciences is hosting a special lecture this week onWednesday February 12, 4:00-5:00pm. The speaker is Lev Jacob Spivak-Birndorf, Indiana University. He is speaking on "Stable Nickel Isotope Fractionation During Rock Weathering: New Insights into the Biogeochemical Cycle of Nickel". Abstract below.
The lecture will be held in Room 1544 C. C. Little Building, Wednesday February 12, 4:00-5:00pm.
This lecture is free and open to the public. A full schedule for the term may be found on our website:
The Department of Earth and Environmental Sciences is hosting a special lecture this week onWednesday February 12, 4:00-5:00pm. The speaker is Lev Jacob Spivak-Birndorf, Indiana University. He is speaking on "Stable Nickel Isotope Fractionation During Rock Weathering: New Insights into the Biogeochemical Cycle of Nickel". Abstract below.
The lecture will be held in Room 1544 C. C. Little Building, Wednesday February 12, 4:00-5:00pm.
This lecture is free and open to the public. A full schedule for the term may be found on our website:
Best regards, -Anne
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Anne Hudon
Academic Student Services
Department of Earth and Environmental Sciences
University of Michigan
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Abstract:
There is growing interest by researchers to better understand the biogeochemical cycles of many trace metals. Analytical techniques to measure stable Ni isotopes have been developed over the last few years, and there have been recent efforts to use this new tool to better constrain the biogeochemical cycle of Ni in the present and past. Rock weathering is an important process for transferring many elements between the lithosphere, atmosphere, hydrosphere and biosphere. This talk will focus on an investigation of stable Ni isotopes in deeply weathered ultramafic rocks, with the aim of providing new insight into the influence of weathering processes on the cycling of Ni in fresh waters and the ocean. Nickel isotopes were measured in host rocks and different types of lateritic weathering products that formed on an ultramafic body in North Carolina. As ultramafic rocks are progressively leached by water some of their original Ni remains in residual phases formed from immobile elements (e.g., Fe-oxides). Another portion of the Ni is dissolved and mobilized in fluids where it can precipitate in secondary hydrous silicates or get released to river and ground waters. Nickel associated with residual oxide weathering products is isotopically light compared to the host rocks, while fluid mobilized Ni that was then deposited in hydrous silicates is isotopically heavier. Experiments in our lab show that Ni isotopes fractionate during sorption to and co-precipitation in Fe-oxides, with the solid phase preferentially incorporating light isotopes. It is likely that heavy isotope composition of Ni that is mobilized in fluids during weathering results from the retention of light Ni in the residual Fe-oxides. I suggest that this process plays an important role in controlling the isotopic composition of Ni that is dissolved in the oceans and surface/ground waters.
There is growing interest by researchers to better understand the biogeochemical cycles of many trace metals. Analytical techniques to measure stable Ni isotopes have been developed over the last few years, and there have been recent efforts to use this new tool to better constrain the biogeochemical cycle of Ni in the present and past. Rock weathering is an important process for transferring many elements between the lithosphere, atmosphere, hydrosphere and biosphere. This talk will focus on an investigation of stable Ni isotopes in deeply weathered ultramafic rocks, with the aim of providing new insight into the influence of weathering processes on the cycling of Ni in fresh waters and the ocean. Nickel isotopes were measured in host rocks and different types of lateritic weathering products that formed on an ultramafic body in North Carolina. As ultramafic rocks are progressively leached by water some of their original Ni remains in residual phases formed from immobile elements (e.g., Fe-oxides). Another portion of the Ni is dissolved and mobilized in fluids where it can precipitate in secondary hydrous silicates or get released to river and ground waters. Nickel associated with residual oxide weathering products is isotopically light compared to the host rocks, while fluid mobilized Ni that was then deposited in hydrous silicates is isotopically heavier. Experiments in our lab show that Ni isotopes fractionate during sorption to and co-precipitation in Fe-oxides, with the solid phase preferentially incorporating light isotopes. It is likely that heavy isotope composition of Ni that is mobilized in fluids during weathering results from the retention of light Ni in the residual Fe-oxides. I suggest that this process plays an important role in controlling the isotopic composition of Ni that is dissolved in the oceans and surface/ground waters.
