Isotopic Constraints on Earth System Processes. Группа авторов

flow velocity and fracture spacing. Chapters Eleven and Twelve expand on this work to explore the utility of calcium and sulfur isotope dynamics under conditions of microbially induced carbonate mineralization.

      In Chapter Thirteen, Messa et al. build upon much of the original stable Ca isotope research that Don was involved in when “Biological control of calcium isotopic abundances in the global calcium cycle” was published by Skulan et al. in 1997. This work, of which Don was second author on, was one of the original projects that illustrated stable Ca isotope fractionation within food chains, revealing that predators exhibit lighter stable Ca isotope ratios than their prey. This chapter expands upon this discovery, and a subsequent study by Skulan and DePaolo (1999), by detailing how stable Ca isotope ratios can reveal more than trophic level positioning, but also inter‐organism Ca isotope fractionation caused by diverse metabolic processes such as the generation of various hard tissues throughout an individual’s lifecycle.

      The editors and authors gratefully acknowledge the reviewers’ comments, which greatly improved the manuscripts herein. We also wish to express our gratitude for the hard work, thoughtful comments, and diligence of the editorial staff at AGU and Wiley.

       Kenneth W. W. Sims Department of Geology and Geophysics University of Wyoming, USA

       Kate Maher School of Earth, Energy and Environmental Sciences Stanford University, USA

       Daniel P. Schrag Department of Earth and Planetary Sciences Harvard University, USA

REFERENCES

      1 Baxter, E.F., Caddick, M.J., & Dragovic, B. (2017). Garnet: A rock forming mineral petrochronometer. Reviews in Mineralogy & Geochemistry, 83, 469–533. https://doi.org/10.2138/rmg.2017.83.15

      2 Baxter, E.F., Ague, J.J., & DePaolo, D.J. (2002). Prograde temperature‐time evolution in the Barrovian type‐locality constrained by precise Sm/Nd garnet ages from Glen Clova, Scotland. Journal of the Geological Society, London, 159, 71–82. http://dx.doi.org/10.1144/0016‐76901013

      3 Christensen, J.N., Rosenfeld, J.L., & DePaolo, D.J. (1989). Rates of tectonometamorphic processes from rubidium and strontium isotopes in garnet. Science, 244, 1465–1469. doi: 10.1126/science.244.4911.1465

      4 DePaolo, D.J. (1981). Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization. Earth and Planetary Science Letters, 53(2), 189–202. https://doi.org/10.1016/0012‐821X(81)90153‐9

      5 DePaolo, D. J. (2006). Isotopic effects in fracture‐dominated reactive fluid–rock systems. Geochimica et Cosmochimica Acta, 70(5), 1077–1096. https://doi.org/10.1016/j.gca.2005.11.022

      6 Hammersley, L., & DePaolo, D. J. (2006). Isotopic and geophysical constraints on the structure and evolution of the Clear Lake volcanic system. Journal of Volcanological and Geothermal Research, 153, 331–356. https://doi.org/10.1016/j.jvolgeores.2005.12.003

      7 Jellinek, A. M., & DePaolo, D. J. (2003). A model for the origin of large silicic magma chambers: precursors of caldera‐forming eruptions. Bulletin of Volcanology, 65(5), 363–381. https://doi.org/10.1007/s00445‐003‐0277‐y

      8 Lassiter, J. C., & Hauri, E. H. (1998). Osmium‐isotope variations in Hawaiian lavas: evidence for recycled oceanic lithosphere in the Hawaiian plume. Earth and Planetary Science Letters, 164(3–4), 483–496. https://doi.org/10.1016/S0012‐821X(98)00240‐4

      9 Richter, F. M., Davis, A. M., DePaolo, D. L., & Watson, E. B. (2003). Isotope fractionation between molten basalt and rhyolite. Geochimica et Cosmochimica Acta, 67, 3905–3923. https://doi.org/10.1016/S0016‐7037(03)00174‐1

      10 Simon, J. I., & DePaolo, D. J. (2010). Stable calcium isotopic composition of meteorites and rocky planets. Earth and Planetary Science Letters, 289, 457–466. https://doi.org/10.1016/j.epsl.2009.11.035

      11 Sims, K. W. W., DePaolo, D. J., Murrrell, M. T., Baldridge, W. S., Goldstein, S. J., & Clague, D. (1995). Mechanisms of magma generation beneath Hawaii and Mid–Ocean ridges: U–Th and Sm–Nd isotopic evidence. Science, 267, 508–512. https://doi.org/10.1126/science.267.5197.508

      12 Sims, K. W. W., Murrell, M. T., DePaolo, D. J., Baldridge, W. S., Goldstein, S. J., Clague, D., & Jull, M. (1999). Porosity of the melting zone and variations in the solid mantle upwelling rate beneath Hawaii: Inferences from 238U–230Th–226Ra and 235U‐231Pa disequilibria. Geochimimica et Cosmochimica Acta, 63, 23, 4119–4138. doi: 10.1016/S0016‐7037(99)00313‐0

      13 Skulan, J., DePaolo, D. J., & Owens, T. L. (1997). Biological control of calcium isotopic abundances in the global calcium cycle. Geochimica et Cosmochimica Acta, 61(12), 2505–2510. https://doi.org/10.1016/S0016‐7037(97)00047‐1

      14 Skulan, J., & DePaolo, D. J. (1999). Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates. Proceedings of the National Academy of Sciences, 96(24), 13709–13713. https://doi.org/10.1073/pnas.96.24.13709

      ABOUT THE COMPANION WEBSITE

      This book is accompanied by a companion website:

       www.wiley.com\go\sims\isotopic_constraints

      This website includes:

      Supplementary data for chapters 2 and 3.

      DEDICATION

       Education isn’t filling a vessel, it is lighting a fire

      —W. B. Yeats

      Donald J. DePaolo commenced his scientific pursuits during a period when rapid technological advances in analytical mass spectrometry spawned an era of isotopic exploration and discovery, cementing the field of isotope geochemistry as a cornerstone discipline within the geosciences.

      For his Ph.D. thesis at Caltech, under the supervision of Gerald Wasserberg, Don measured neodymium isotopes in volcanic rocks, combining the data with a model of crustal formation to define Earth’s mantle structure. It was simple, powerful, and changed the way we think about the structure of the Earth.

      From those early days, it was clear that Don had great potential, but few could have predicted the extraordinary trajectory his career would follow, first at UCLA until 1988, and then at UC Berkeley. Over more than 40