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Sublithospheric diamonds: Plate tectonics from Earth's deepest samples (Annual Reviews, 2024)
✦ Wizard Island in Crater Lake, Oregon, field work 2011. (photo: Steve Shirey)
Arc volcanism, the product of plate subduction in the oceans at island arcs and on the continents at continental margins, is a prime place on Earth where crust differentiates into more silicic compositions and is added to continental margins. It is a natural laboratory for the study of volcanic processes and crust formation.
Arc volcanism, the product of plate subduction in the oceans at island arcs and on the continents at continental margins, is a prime place on Earth where crust differentiates into more silicic compositions and is added to continental margins. It is a natural laboratory for the study of volcanic processes and crust formation.
In the papers listed here, all of which were done with potsdocs or visiting students, there are three basic advances:
Demonstration of oxidizing conditions in arc mantle xenoliths that indicate Os mobility and enrichment (papers 43 and 58).
Significant volumes of trapped baslt in the crustal sections of the Cascades arc that react with arc lavas but yet are visible only with Os isotopes and invisible with Sr, Nd, And Pb (papers 74, 76, 100, 101, and 122).
Long residence times (e.g. many tens of Myr) for pyroxene megacrysts in Proterozoic anorthosites at the moho and a suggested continental arc setting (paper 118).
Relevant Publications
Relevant Publications
122. Ankney, M. E., Shirey, S. B., Hart, G. L., Bacon, C. R., & Johnson, C. M. (2016). Os and U–Th isotope signatures of arc magmatism near Mount Mazama, Crater Lake, Oregon. Earth and Planetary Science Letters, 437 IS -, 25–34. https://doi.org/10.1016/j.epsl.2015.12.001
122. Ankney, M. E., Shirey, S. B., Hart, G. L., Bacon, C. R., & Johnson, C. M. (2016). Os and U–Th isotope signatures of arc magmatism near Mount Mazama, Crater Lake, Oregon. Earth and Planetary Science Letters, 437 IS -, 25–34. https://doi.org/10.1016/j.epsl.2015.12.001
118. Bybee, G.M., Ashwal, L.D., Shirey, S.B., Horan, M., Mock, T., and Andersen, T.B. (2014) Pyroxene megacrysts in Proterozoic anorthosites: Implications for tectonic setting, magma source and magmatic processes at the Moho: Earth And Planetary Science Letters, v. 389, 74–85. https://doi.org/10.1016/j.epsl.2013.12.015
118. Bybee, G.M., Ashwal, L.D., Shirey, S.B., Horan, M., Mock, T., and Andersen, T.B. (2014) Pyroxene megacrysts in Proterozoic anorthosites: Implications for tectonic setting, magma source and magmatic processes at the Moho: Earth And Planetary Science Letters, v. 389, 74–85. https://doi.org/10.1016/j.epsl.2013.12.015
101. Jicha, B.R., Johnson, C.M., Beard, B.L., Hart, G.L., Shirey, S.B., and Singer, B., 2009, Discriminating assimilants and decoupling deep- vs. shallow-level crystal records at Mount Adams using 238U–230Th disequilibria and Os isotopes: Earth and Planetary Science Letters, v. 277, p. 38-49. http://dx.doi.org/10.1016/j.epsl.2008.09.035
101. Jicha, B.R., Johnson, C.M., Beard, B.L., Hart, G.L., Shirey, S.B., and Singer, B., 2009, Discriminating assimilants and decoupling deep- vs. shallow-level crystal records at Mount Adams using 238U–230Th disequilibria and Os isotopes: Earth and Planetary Science Letters, v. 277, p. 38-49. http://dx.doi.org/10.1016/j.epsl.2008.09.035
100. Jicha, B.R., Hart, G.L., Johnson, C.M., Hildreth, W., Beard, B.L., Shirey, S.B., and Valley, J.W., 2009, Isotopic and trace element constraints on the petrogenesis of lavas from the Mount Adams volcanic field, Washington: Contributions to Mineralogy and Petrology, v. 157, p. 189-207. http://dx.doi.org/10.1007/s00410-008-0329-6
100. Jicha, B.R., Hart, G.L., Johnson, C.M., Hildreth, W., Beard, B.L., Shirey, S.B., and Valley, J.W., 2009, Isotopic and trace element constraints on the petrogenesis of lavas from the Mount Adams volcanic field, Washington: Contributions to Mineralogy and Petrology, v. 157, p. 189-207. http://dx.doi.org/10.1007/s00410-008-0329-6
76. Hart, G.L., Johnson, C.M., Hildreth, W., and Shirey, S.B., 2003, New Os isotope constraints on intra-crustal recycling of crustal domains with discrete ages: Geology, v. 31, p. 427-430. http://dx.doi.org/10.1130/0091-7613(2003)031%3C0427:NOIEFI%3E2.0.CO;2
76. Hart, G.L., Johnson, C.M., Hildreth, W., and Shirey, S.B., 2003, New Os isotope constraints on intra-crustal recycling of crustal domains with discrete ages: Geology, v. 31, p. 427-430. http://dx.doi.org/10.1130/0091-7613(2003)031%3C0427:NOIEFI%3E2.0.CO;2
74. Hart, G.L., Johnson, C.M., Shirey, S.B., and Clynne, M.A., 2002, Osmium isotope constraints on lower crustal recycling and pluton preservation at Lassen Volcanic Center, CA: Earth and Planetary Science Letters, v. 199, p. 269-285. https://doi.org/10.1016/S0012-821X(02)00564-2
74. Hart, G.L., Johnson, C.M., Shirey, S.B., and Clynne, M.A., 2002, Osmium isotope constraints on lower crustal recycling and pluton preservation at Lassen Volcanic Center, CA: Earth and Planetary Science Letters, v. 199, p. 269-285. https://doi.org/10.1016/S0012-821X(02)00564-2
58. Brandon, A.D., Becker, H., Carlson, R.W., and Shirey, S.B., 1999, Isotopic constraints on time scales and mechanisms of slab material transport in the mantle wedge: evidence from the Simcoe mantle xenoliths, Washington, USA: Chemical Geology, v. 160, p. 387-407. https://doi.org/10.1016/S0009-2541(99)00109-6
58. Brandon, A.D., Becker, H., Carlson, R.W., and Shirey, S.B., 1999, Isotopic constraints on time scales and mechanisms of slab material transport in the mantle wedge: evidence from the Simcoe mantle xenoliths, Washington, USA: Chemical Geology, v. 160, p. 387-407. https://doi.org/10.1016/S0009-2541(99)00109-6
43. Brandon, A.D., Creaser, R.A., Shirey, S.B., and Carlson, R.W., 1996, Osmium recycling in subduction zones: Science, v. 272, p. 861-864. https://doi.org/10.1126/science.272.5263.861
43. Brandon, A.D., Creaser, R.A., Shirey, S.B., and Carlson, R.W., 1996, Osmium recycling in subduction zones: Science, v. 272, p. 861-864. https://doi.org/10.1126/science.272.5263.861
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