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Geocheminar - fall-2018

Andreas Hertwig (UCLA) One method, two stories: ion microprobe studies of zircon in jadeitites and the age of chondrules in the Acfer 094 meteorite

Sept. 27, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Andreas Hertwig - UCLA
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Rita Economos (SMU) Igneous geochemistry, intrusive style and high temperature structures constrain the transition from Sevier to Laramide orogenesis in the Southwestern U.S.

Oct. 4, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Rita Economos - SMU
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Jabrane Labidi (UCLA) - Volcanic gasses include slab- and air-derived nitrogen but no contributions from the mantle: a 15N15N perspective

Oct. 11, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Jabrane Labidi - UCLA
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Variable d15N in volcanic gases are typically interpreted as proxies for the contribution of mantle versus slab-derived nitrogen. However, air lies between the mantle and the crust. Hence d15N values alone are blind to air contributions to geological fluids. In order to disambiguate the nitrogen cycle in volcanoes, we determined the N content, d15N and 15N15N excess measured on the Panorama mass spectrometer of 35 N2 samples from a wide variety of crustal and volcanic settings. We find that the low d15N observed in volcanic gases are not mantle contributions but instead must result from isotope fractionation of air-derived N2 in hydrothermal systems. This observation implies that volcanic N2 is dominated by crustal components and air, thus redefining the geodynamic nitrogen sources to the atmosphere.

Paul Warren (UCLA) The lunar crust as a heat flow province: Exploiting new Paige-Siegler Diviner results to constrain the bulk composition and origin of the Moon

Oct. 18, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Paul Warren - UCLA
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Corliss Kin I Sio (LLNL) The Role Of Iron Isotopes In Petrology: From Volcanic Eruptions To The Origin Of Pallasites

Oct. 25, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Corliss Kin I Sio - Lawrence Livermore National Laboratory
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Greenhouse Gas Measurements in Surface Waters of the Baltic Sea on a Voluntary Oberving Ship (VOS) - From Novel Instrumentation to New Monitoring Strategies

Nov. 1, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Gregor - Leibniz Institut für Ostseeforschung Warnemünde an der Universität Rostock
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The Baltic Sea, one of the largest brackish water systems on earth, with various sub-basins characterized by horizontal and vertical salinity gradients, is a unique system to investigate the marine cycling of carbon dioxide and methane. Since 2003, IOW is operating gas analytical instrumentation on the Voluntary Observation Ship (VOS) Finnmaid, commuting between Lübeck and Helsinki and back roughly every three days. The system, which began as an amendment to the Finnish Alg@line project, has originally been set up for the measurement of pCO2 in surface waters, but has since then been extended by continuous measurements of oxygen and methane partial pressure. Further extension in the framework of the Integrated Carbon Observation System (ICOS) is planned for mid-2018. The presentation highlights the potential of continuous surface measurements to depict seasonal cycles as well as interannual variability of trace gas patterns, and to get insights into the underlying processes, including production, mineralization, upwelling, and mixed layer dynamics. In particular, the use for a quantitative assessment of primary production is given. The talk also seeks to communicate the vision of a network of VOS lines across the Baltic for a better monitoring of acidification and eutrophication in the Baltic Sea.

Carolina Lithgow-Bertelloni (UCLA) 3-D experimental investigations of mantle plumes

Nov. 8, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Carolina Lithgow-Bertelloni - UCLA
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Ellen Alexander (UCLA) Isotopic and Geochemical Constraints on Pre- and Syn-collisonal Crustal Thickening of Southern Tibet

Nov. 15, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Ellen Alexander - UCLA
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Beth Ann Bell (UCLA) Microscale Secondary Phases in Detrital Zircon Record >1 Ga of Metamorphism in the Yilgarn Craton

Nov. 29, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Beth Ann Bell - UCLA
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*Cancelled* Doug Rumble (Carnegie Institution for Science) Methane, Plate Tectonics, Mud Volcanoes, and Microbes

Dec. 6, 2018
3:30 p.m. - 4:30 p.m.
3853 Slichter

Presented By:

  • Doug Rumble - Carnegie Institution for Science
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